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2013 Biology STAAR Review

Welcome to your 2013 Biology STAAR Review. This packet has been prepared to get you ready for your STAAR test in 2013. This packet should be used as a study guide to help you prepare for your upcoming test. Take notes and star, underline, highlight etc… anything you may be unsure of and would like to discuss with Coach Furin during class. I am here to help so please don’t be afraid to ask questions!!!

Station 1: Cell Structure and Function

Biological Organization Atoms biological molecules cells tissues organs organ systems organism population community ecosystem biosphere Atoms of different elements (such as carbon, hydrogen, oxygen, nitrogen and phosphorus), join together to form: Biological Molecules. Biological molecules join together to form cells. The cell is the basic unit of living organism. Cells join together to form Tissues. Tissues join together to form organs. Organs join together to form Systems. Systems join together to form an organism.

Organisms join together to form populations.

Populations join together to form a community. A community is several interacting populations that live in a common environment. Communities join together to form an Ecosystem. An ecosystem is the living and nonliving parts of an environment. Ecosystems join together to form the biosphere. The biosphere is the portion of the earth that supports life.

Biomolecules(polymers) - Large organic molecules that make up living things. Organic molecules are CARBON based. 4 types of biomolecules:

Carbohydrates – made of carbon, hydrogen and oxygen. The ratio of Hydrogen to Oxygen in Carbs is always 2:1. Living organisms use carbohydrates such as a source of energy. Plants store energy in the form of STARCH. Starch is a polysaccharide carbohydrate formed by linking together monosaccharides in a process called dehydration synthesis. The other two groups of polysaccharides are cellulose (the most abundant organic compound on earth) and glycogen (stored energy in animals). Glucose, fructose and galactose are simple sugars (monosaccharide), the smallest units (monomers) of a carbohydrate. Sucrose (glucose + fructose) is a disaccharide commonly known as table sugar. The reverse of dehydrations synthesis-the breaking down of large molecules by adding water is know as HYDROLYSIS.

Lipids- Store energy and make up cell membranes. Composed of C, H and O just like Carbohydrates but the ratio of H:O is not 2:1 1. Fats, oils and waxes 2. Phospholipids - lipids that form cell membranes.

Proteins- Made up of amino acids linked together by peptide bonds. Composed of C, H, O & N. Proteins have many important functions. Example: Hemoglobin is a protein in red blood cells that carries oxygen. There are 20 common amino acids that make up proteins. You don’t need to know the names of the amino acids, just know that they are joined together to make proteins.

Proteins are needed for: • Growth, Maintenance & Repair • Moving substances in and out of the cell • Regulating chemical reactions • Enzymes are usually proteins. They speed up the rate of chemical reactions. Enzymes are found in all living cells.

Nucleic acids –this is what the NA in DNA and RNA stands for-They store and transmit genetic (hereditary) information and are involved in making proteins. There monomer is called a NUCLEOTIDE = SUGAR, PHOSPHATE AND A NITROGEN BASE. Each organism is different because of the sequence of the nitrogen bases in their DNA. These nitrogen bse sequences also direct the synthesis of all of an organism’s protein synthesis. Animals get necessary biological molecules, or the components of biomolecules, from the foods they eat.

Plant and Animal Cells-

Plant cellsare autotrophic, multicellular eukaryotic organisms that have:

 Plant cells have a cell wall made of cellulose which gives the cell structure and support.

 Plant cells have organelles called chloroplasts that contain chlorophyll and other pigments necessary for photosynthesis.

 The chlorophyll in the chloroplasts captures solar energy for photosynthesis.

 During plant cell mitosis the interphase occurs as a cell plate is built between the two new daughter cells.

 Plant cells have a large central vacuole for storing starch

Both plant and animal cells have:

 Mitochondria for cellular respiration (harnessing energy)  A plasma membrane that surrounds the cell.  A nucleus that contains the DNA (eukaryotic). DNA has the genetic code for making all the proteins in a cell. Other cell organelles include:

 Lysosome – organelle that carries out the digestive processes in the cell.  Rough Endoplasmic Reticulum – has ribosomes that makes proteins.  Smooth Endoplasmic Reticulum – detoxifies and makes lipids. Has no attached ribosomes.  Golgi apparatus – prepares, stores, sorts and distributes proteins.  Ribosomes- where proteins are made.

Cell Division-

Bacteria divide asexually by binary fission. Bacteria do not have a nucleus (prokaryotic).

Cell Cycle-interphase, prophase, metaphase, anaphase & telophase followed by cytokinesis

Mitosis - Cell division in cells that have a nucleus (eukaryotes). Starts with prophase>>> metaphase>>>anaphase>>>telophase>>>cytokinesis

Mitosis produces cells that are genetically identical to the parent cell.

 If the parent cell has 46 chromosomes… the daughter cells will also have 46 chromosomes (diploid # of chromosomes. Meiosis- the production of sex cells or gametes. 4 new cells are produced with half the number of chromosomes (haploid # of chromosomes).

 If the parent cell has 46 chromosomes, each of the daughter cells will have 23. Meiosis produces eggs and sperm.

 Egg cells and sperm cells must have half the number of chromosomes as the parent cell… so that the zygote has the proper # of chromosomes. A zygote is a fertilized egg.  Nondisjunction occurs during Anaphase I of meiosis and results in the failure of the chromosomes to separate properly when the chromosomes appear as tetrads.

The Plasma Membrane and Homeostasis

The plasma membrane (also called the cell membrane) is a membrane made up of phospholipid bilayer molecules. It serves as a boundary around the cell.

The plasma membrane is semi-permeable. It allows only certain things into and out of the cell. It helps to maintain the homeostasis of the cell.

Homeostasis is maintaining a balance, or regulating internal conditions in an organism despite external changing conditions.

 Ex. All living organisms must have the proper balance of temperature, water, energy, pH (relative acidity-H+ ions- or baseness-OH- ions- of a substance) etc. Cell Transport-

Passive Transport- When substances pass across the membrane without requiring cellular energy moving with the concentration gradient.

 Diffusion is the movement of a substance from an area of greater concentration to an area of lesser concentration…ex. Mixing Water and Kool-Aid

 Osmosis is the diffusion of water across a membrane from an area of high water concentration to an area of low water concentration….ex. placing a salt water fish in freshwater will cause the cells of the fish to swell and explode (lyse)-hypotonic solution…ex. Placing a freshwater fish into salt water will cause the cells of the fish to shrink (plasmolysis)—hypertonic solution.

 The membrane is usually the plasma membrane.

 Osmosis does not require cellular energy, so it is a form of passive transport.  When a cell is at equilibrium (no net movement of water in or out of the cell) the cells is said to be in an isotonic solution.

Active Transport- When cell energy (in the form of ATP) is required for substances to pass across the plasma membrane….ex. phagocytosis, endocytosis, exocytosis all move against the concentration gradient and require energy from ATP to do so.

Cell Respiration

Cell Respiration-The process of transferring stored energy from glucose to energy for the cell (ATP).

When animals eat food their digestive systems break it down into molecules like glucose.

One minor problem! Glucose is not used directly for energy. So these molecules are transported to the cells throughout the body where they enter the mitochondria and are broken down through cellular respiration (aerobic-with oxygen- and anaerobic-without oxygen) and converted into the stored chemical energy of ATP molecules which are the only source of energy for chemical work in the cell. ATP is the molecule that the cell can directly use for energy.

To make ATP in the mitochondria the cell needs: glucose and oxygen.

This is the reason we breathe! Our cells must have oxygen to make ATP (energy) for the cell.

What are the products of cellular respiration?

 ATP (energy for the cell)  Carbon dioxide

 Water

(You exhale carbon dioxide because it’s a waste product of the cell.) The reaction for cellular respiration is:

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

Glucose + Oxygen carbon dioxide + water + energy

Photosynthesis

Photosynthesis is the process by which plants make their own food (glucose).

The cell organelle where photosynthesis takes place is called the chloroplast which also contain other pigments (carotenoids & Xanthophylls) that increases the rate of photosynthesis by capturing more of the wavelengths of the spectrum of light form the sun.

Photosynthesis builds glucose molecules. The formula for glucose is- C6H12O6 which is a simple carbohydrate known as a monosaccharide that when linked together make starch (polysaccharide)

For photosynthesis to take place the plant cell must have the follwoning raw materials: sunlight, carbon dioxide, and water.

The formula for photosynthesis is:

6CO2 + 6H2O + sunlight C6H12O6 + 6O2

Carbon Dioxide + water + energy glucose + oxygen

Compare the formulas for photosynthesis and cellular respiration.

Photosynthesis- 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2

Cellular respiration- C6H12O6 + 6O2 6CO2 + 6H2O + ATP

They are the opposite! Know one and you will know the other!

Viruses- are made up of a core of nucleic acid (DNA or RNA) surrounded by a protein coat (capsid). They are considered to be non-living because they don’t respire, grow, metabolize nutrients or develop. They can only reproduce by invading a cell. The are much smaller than bacteria. Most are pathogenic (cause diseases) and some are very virile (deadly).

Bacteriophage- a virus that attacks bacterial cells.

Before the virus can replicate, it must attach to and enter a host cell. The virus is shaped to lock on to a receptor site of a specific host cell. The virus injects its nucleic acid (DNA or RNA) into the host cell. The host cell makes copies of the viral genes and proteins and the new viruses are assembled. The new viruses (virions) burst (lyse) out of the host cell, killing it. They can now attack and kill other host cells (known as the LYTIC CYCLE of infection).

Not all viruses immediately kill the cells they infect. After the viral nucleic acid is injected into the host cell, it may remain inactive for a period of time (LYSOGENIC CYCLE of infection).

Viruses cause diseases such as smallpox, AIDS, influenza (flu), warts and the common cold.

The HIV virus (which causes AIDS) attacks a type of white blood cell called helper T cells. Helper T cells help the body fight infection. AIDS attacks the host’s immune system making them weaker and susceptible to secondary infections.

Viruses have a specific receptor sites that will only fit a certain type of cell.

Antibiotics are used to kill bacterial infections, but will not kill viral infections.

Vaccines are made of a weaker or similar virus that triggers the body to make antibodies (the bodies first line of defense against an invader) to prepare the body to fight off the viral infection.

Station 2: Mechanisms of Genetics

DNA- (deoxyribonucleic acid) is found in the nucleus of cells. It contains the hereditary information for making proteins.

DNA is made up of building blocks called nucleotides. Each nucleotide is made up of

1. Sugar (deoxyribose) 2. Phosphate

3. One of the following nitrogen bases: adenine, thymine, cytosine, or guanine

The nucleotides are bonded in a specific way.

Adenine always bonds with Thymine.

Cytosine bonds with Guanine.

The shape of DNA is described as a double helix or a twisted ladder as first shown by Watson and Crick.

The exact sequence of the nitrogen bases determines the traits of an organism.

DNA is the molecule that determines an organism’s eye color, body structure, protein structures and cellular enzyme production.

The components that make up the genetic code are common to all organisms.

Terms that relate to DNA: genes, chromatin, chromatid, chromosomes, genetic material, allele, deoxyribonucleic acid, genome, and nucleic acid (cytosine+guanine, adenine + thymine (uracil in RNA).

DNA Replication Before the cell can divide, the DNA must replicate or make a copy of itself.

The sides of the DNA molecule separate with the help of DNA helicase (enzyme that unzips strand).

New nucleotides bond with the existing nucleotides.

Two identical strands of DNA are formed.

RNA- Ribonucleic Acid

There are 3 types of RNA involved in making proteins:

mRNA = messenger RNA tRNA = transfer RNA rRNA = ribosomal RNA

mRNA (codons) is a copy of the DNA code (made during transcription),

tRNA (anti-codons) carries amino acids to the ribosomes to assemble proteins during translation (protein synthesis) & rRNA is structural in nature and makes up the ribosomes.

RNA is different from DNA in the following ways:

1. RNA is single stranded

2. RNA has the sugar ribose instead of deoxyribose in DNA.

3. The nitrogen bases in RNA are adenine + uracil(instead of thymine), cytosine + guanine.

Adenine bonds with uracil. A-U

Cytosine bonds with Guanine. C-G

A sequence of 3 nucleotides of mRNA is called a codon. Each codon codes for an amino acid.

Example: The codon CCA codes for the amino acid proline –make sure that you know how to use the codon chart for protein synthesis. tRNA has an anti-codon that compliments the mRNA codon and will deliver the correct amino acid to the ribosome for assembly into a protein molecule.

Protein Synthesis (Translation)

DNA has the instructions for making all the proteins needed by the cell. DNA is found in the nucleus of the cell.

(DNA makes up the chromosomes)

Protein synthesis is the process by which the cell makes proteins using the DNA code. Protein synthesis occurs in two steps:

1. transcription – the DNA code is copied to make mRNA.

 The hydrogen bonds between the DNA molecule separate (DNA helicase).

 mRNA nucleotides join one side of the DNA strand to make a copy (polymerases).

 mRNA leaves the nucleus to take the copied DNA code to a ribosome.

2. Translation – tRNA brings amino acids to the ribosomes to make a protein.

Genetics - the study of heredity.

Humans have 23 pairs of chromosomes. Segments of chromosomes that code for specific traits are called genes. Genes come in pairs.

Genes control traits. Chromosomes are made up of DNA. You received one set of chromosomes from your mother (23) and one set from your father (23) to make 23 pairs or 46 chromosomes.

Genes exist in alternative forms called alleles. Alleles are located on chromosome pairs.

Many gene pairs follow Mendel’s law of dominance and recessiveness.

A dominant gene will override or show up over a recessive gene.

A capital letter is used to represent a dominant gene and a lower case letter is used to represent a recessive gene.

For example, free earlobes (unattached) is dominant over attached earlobes.

The phenotype of an organism is the physical appearance, or what you see.

The genotype is the actual genetic makeup.

If both genes are the same, the individual is homozygous.

If the two genes are different, the individual is heterozygous for that trait.

The genetic makeup of organisms can be studied by: DNA fingerprinting, genetic modifications, and chromosomal analysis.

Punnett Squares- can be used to predict the possible genotypes and phenotypes of the offspring.

Before setting up your Punnett square you must first determine what genes can be in the parent’s gametes (sex cells).

During meiosis, the formation of sex cells, the gene pairs will separate and the gametes will receive one of each. The allele for widow’s peak (W) is dominant. The gene for no widow’s peak (w) is recessive. One parent is heterozygous for widow’s peak. The other parent has no widow’s peak. What are the possible genotypes of their offspring?

Heterozygous parent = Ww

Parent with no widow’s peak = ww

Ww x ww

Put the possible genotypes of one parent across the top of the Punnett square and the possible gametes of the other parent down the side.

Fill in the squares.

Set up and complete the Punnett square for this cross in the space below.

EeWW x eeWw - hint: use the foil method

Genetics-Patterns of Inheritance

Genetic traits are not always dominant or recessive. Some traits follow different patterns of inheritance.

Incomplete Dominance

Two different genes, when paired, blend together and produce a 3rd phenotype.

Red snapdragons and white snapdragons produce pink snapdragons.

Codominance – both alleles are expressed.

When a certain variety of black chicken is crossed with a white chicken, all of the offspring are checkered. Both feather colors are equally expressed.

Sex- Linked Traits

 Traits are found on the X sex chromosome.  The Y chromosome does not have a gene for the trait.  Males only have to inherit 1 recessive gene; more males will have the condition.  Example is hemophilia (h) a recessive blood clotting disorder. The normal gene (H) codes for normal clotting.

Sex-Linked Traits

XhXh –female with hemophilia

XHXh – female carrier

XhY – male with hemophilia

XHY – normal male

XHXH – normal female, not a carrier

Multiple Alleles -traits controlled by more than two alleles in a population.

Each individual has two genes for blood type, but 3 alleles exist in our population.

The type A allele and the type B allele are codominant. Type 0 is recessive. This gives us 4 blood types.

A B AB O

Karyotypes

Karyotype – a picture of an organism’s chromosomes.

Normal humans have 23 pairs of chromosomes.

Chromosomes occur in pairs. In humans the 23rd pair is the sex chromosomes.

Females - XX

Males - XY The Y chromosome in males doesn’t really look like a Y. It is much smaller than the X.

Sometimes individuals are born with missing or extra chromosomes. A karyotype can be used to determine if an individual has too many or too few chromosomes.

Trisomy – 3 chromosomes instead of 2

Monosomy – 1 chromosome instead of 2

An extra 21st chromosome is Trisomy 21.

Trisomy 21 is called Down Syndrome.

Meiosis the formation of gametes (egg and sperm). When meiosis occurs normally, each gamete receives 1 of each chromosome.

Sometimes the chromosomes fail to separate during meiosis and gametes will receive extra chromosomes or will be missing chromosomes. This is called nondisjunction.

If these gametes are fertilized, the embryo will have extra or missing chromosomes.

Mutations- are a change in the DNA of a cell.

Mutations can be caused by:

1. Mistakes in replication 2. mistakes in transcription 3. external agents

External agents that can cause mutations:

1. Examples: ultraviolet rays from sun, x-rays

2. Harmful chemicals examples: benzene, asbestos

A mutation will only be passed to the offspring if it occurs in a reproductive cell or gamete.

Occasionally, a genetic mutation will occur that is beneficial to the organism.

The mutation is beneficial if it improves the organism’s chance of survival in a specific environment.

Station 3:Biological Evolution and Classification

Evolution is the theory that organisms change over time. The fossil record indicates that organisms change over time.

Homologous structures are structures that are similar and suggest evolution from a common ancestor.

DNA sequencing is also considered evidence of evolution. Comparing the DNA of different species show how similar or different they are.

Vestigial structures are considered evidence that organisms change over time. Vestigial structures are structures that have little or no function but were probably used by ancestral organisms. The appendix is a vestigial structure.

Boa constrictors and pythons have the remnants of hind legs and pelvic bones. This is another example of vestigial structures.

Natural selection is believed to be the primary mechanism by which populations of organisms change over time.

Natural selection states that organisms with favorable traits are more likely to survive, reproduce, and pass those traits on to their offspring.

The genetic makeup of an individual does not change!

The genetic makeup of a population can change over time.

Natural Selection -A scientific theory that explains the process of evolution.

Natural Selection is based on 4 principles:

1. Variations exist among populations. 2. Organisms produce more offspring than can survive. 3. Organisms compete for natural resources. 4. The individuals that have variations suited to their habitat will survive and reproduce, passing on their genetic makeup to the next generation.

Example of Natural Selection: Among a species of butterfly there is variation in color. Some are green and some are red.

The red butterflies are more easily seen and eaten by the birds than the green butterflies.

More of the green butterflies survive to reproduce. Over time we have more green butterflies than red butterflies. Natural selection has occurred. The gene pool of the population has changed.

Populations evolve; individuals do not!

Scientists predict that natural selection will cause an increase in antibiotic resistant bacteria due to the overuse and misuse of antibiotics.

Example: You have strep throat. There is variation among the species of Streptococcus bacteria that is making you ill. Some bacteria are naturally more resistant to antibiotics than others.

You get a prescription of the antibiotic penicillin. The medicine kills the weaker, least resistant bacteria first.

The doctor tells you to take the antibiotic for seven days. You feel better after 3 days so you stop taking it.

The first few days you take the medicine you continue to kill the weaker bacteria. Because you didn’t take the antibiotic as prescribed, you have left behind the antibiotic resistant bacteria which will reproduce more antibiotic resistant bacteria.

Classification of Organisms

Taxonomy is the science of naming and classifying.

The classification of organisms is a highly debated topic. Many scientists use the 3 domain system.

The 3 domains are: Bacteria, Achaea and Eukaryota.

The 6 kingdom system is also widely used. The 6 Kingdoms are Archaebacteria, Eubacteria, Protista, Fungi, Plant and Animal

The kingdoms are divided into smaller groups called phyla; the phyla are divided into smaller groups and so on…

Kingdom, Phylum, Class, Order, Family, Genus, Species.

Ex: How are Humans Classified?

 Kingdom-Animalia

 Phylum- Chordata

 Class-Mammalia

 Order- Primates

 Family- Hominidae

 Genus-Homo

 Species-Homo sapiens

 Scientific Name- the scientific name, or species name, of an organism includes the genus name followed by the specific name.

 Example of a scientific name or species name: Homo sapiens.  Homo is the genus name

 Sapien is the specific name

The scientific name of an organism should be underlined or in italics. The genus name is capitalized, and the specific name is not.

Example: Felis domesticus (house cat)

The kingdoms Archaebacteria and Eubacteria include all of the prokaryotes. Prokaryotes are cells that do not have a membrane-bound nucleus.

Kingdom Archaebacteria

These “extreme bacteria” are believed to be the oldest life forms.

Bacteria in this kingdom are called the “extremists” because they live in extreme habitats, often where no other organisms can survive. Their biochemical diversity allows them to live in a wide variety of environments.

Some Archaebacteria live in oxygen-free environments such as marshes and swamps or the guts of mammals such as cows. These Archaebacteria produce methane gas.

One type of Archaebacteria lives in water with high concentrations of salt such as the Great Salt Lake and the Dead Sea.

Other Archaebacteria thrive in the hot, acidic water of hot sulfur springs.

Some live in deep cracks in the ocean floor where temperatures are often over 100˚c.

Kingdom Eubacteria

Some bacteria have cilia or flagella which allows them to move.

The prokaryotes in the kingdom Eubacteria are more common. The prokaryotes in this kingdom are often referred to as the “true bacteria”.

Bacteria are often classified according to their shape.

Cocci- round

Bacilli- rod shaped

Spirillum- spiral shaped Some Eubacteria cause disease, but most of them do not. A few diseases caused by Eubacteria are tetanus, typhoid fever, tuberculosis, diphtheria, strep infections, dental cavities and staph infections.

Most bacterial infections can be cured with antibiotics.

The spread of harmful bacteria can be reduced by: 1. Cooking foods properly 2. Washing hands with soap and water 3. Covering mouth and nose when coughing and sneezing 4. Limiting the touching of mouth, eyes and nose

Antibiotics, such as penicillin, work by preventing the cell walls of bacteria from developing properly. The bacterial cell walls develop holes, and the cell will die.

Some bacteria are helpful, such as the bacteria that aid in digestion, and the nitrogen-fixing bacteria on the roots of plants. Legumes are plants with root nodules containing nitrogen-fixing bacteria. Soybeans and peanuts are legumes.

Swiss cheese is made with the help of bacteria.

Bacteria are important decomposers. Decomposers break down dead and decaying organic matter.

Bacteria reproduce by binary fission.

Protista, Plantae and Animalia, the Fungi Kingdom is eukaryotic. Eukaryotic cells have a nucleus.

Kingdom Protista- is the most diverse kingdom. These organisms may be unicellular, multicellular, autotrophic, heterotrophic, microscopic or very large.

Protists are eukaryotes. Eukaryotic cells have a true nucleus and other membrane- bound organelles. Protists may be made up of one or more eukaryotic cells.

Kingdom Protista is divided into 3 main groups:

 Plant-like protests (algae) o Algae produce much of the Earth’s oxygen as a product of photosynthesis.

o Green algae are believed to be the ancestors of plants  Animal-like Protists (protozoa) o Classified according to how they move. Some, like the Paramecium, move by tiny hair-like projections called cilia.

o Some protozoa move by long whip- like structures called flagella.

o One type of flagellate protozoan lives in the gut of termites. The flagellate digests the cellulose (wood) for the termite. This is an example of a mutualistic relationship. Both the termite and the protozoan benefit.

o Some protozoa, like the amoeba, move by pseudopods which are flowing extensions of the cell.

o Some protozoa do not move at all and live as parasites in other organisms. Malaria is caused by a protozoan that is transmitted by mosquitoes. o  Fungus-like Protists (slime mold)

Kingdom Fungi- includes mushrooms, yeasts, mold, mildew and many parasitic species.

Fungi can be unicellular, but most are multi-cellular.

Fungi cells have cell walls made of chitin.

Fungi are heterotrophs. They cannot make their own food like plants; they take in food. Fungi obtain food by secreting digestive enzymes outside the cell and absorbing the digested nutrients. This is called extracellular digestion.

Many fungi are decomposers. Decomposers break down dead and decaying organisms.

The antibiotic penicillin is derived from Penicillium mold. Antibiotics kill bacteria by preventing their cell walls from developing properly.

Ringworm is caused by a parasitic fungus that attacks the skin.

Yeast is a fungus that is used in the baking of bread.

Kingdom Plantae- Plants are multicellular (more than one cell) autotrophs (make their own food by photosynthesis). Plants include mosses, ferns, trees, grasses and many more.

Plant cells have thick cell walls made of cellulose. The cell wall gives the plant structure and support.

Plant cells have chloroplasts which contain chlorophyll for photosynthesis.

Nonvascular plants like mosses are small and do not have vessels for transporting water and nutrients.

Vascular plants have vessels for transporting water and nutrients.

Some plants, like ferns, reproduce by forming spores. The spores are usually found on the underside of the fronds.

Some plants reproduce by forming seeds in flowers.

Some plants produce seeds in fruit. Pine trees, spruce, fir and hemlock are examples of conifers.

Annual Rings- A cross section of a tree shows annual growth rings. Years of sufficient rainfall will produce thicker rings than dryer years.

Animals can be divided into the invertebrates and vertebrates. Invertebrates do not have a backbone. Vertebrates do have a backbone.

Kingdom Animalia - Invertebrates

The Kingdom Animalia consists of multicellular heterotrophs (must get food from another source) that move to obtain food. Animal cells do not have a cell wall.

Cnidarians- Jellyfish, coral and the sea anemone. This group of invertebrates has tentacles with stinging cells.

Flatworms tapeworm. Roundworms nematoades. Segmented worms  earthworm.

Mollusks- The mollusks have a muscular foot for movement and a mantle. In mollusks with shells, the mantle secrets the shell. Includes clams, oysters, snails, octopus, squid and chambered nautilus.

Arthropods- have jointed appendages, an exoskeleton, and body segments.

 Arachnids- Spiders, ticks and mites  Crustaceans- lobsters, crabs, crawfish  Insects- fly, grasshopper, ladybug, etc.  Centipedes and millipedes

Echinoderms- They move by tiny tube feet, have spiny skin and live in the ocean.

Ex. sea star, sea cucumber, sand dollar

Invertebrate Chordates- Have a notochord but no vertebrae. Ex. Tunicate.

Kingdom Animalia - Vertebrates

The vertebrates include:

Jawless Fish. Ex. Lamprey

Cartilaginous Fish- have skeletons made of cartilage. Ex. Shark and ray

Bony Fish- have skeletons made of bone.

Amphibians – They have thin moist skin, must return to water for fertilization, eggs lack a protective shell and must be laid in water. Amphibian means “double life”. Include frogs, toads, and salamanders. Reptiles- reptiles are adapted for life on land with water-tight skin, internal fertilization and an amniotic egg. An amniotic egg provides nourishment for the embryo and has protective membranes, and a shell that prevents drying. Reptiles include snakes, lizards, turtles, alligators and crocodiles.

Birds (Aves) – Have adaptations for flight such as hollow bones, feathers and wings. Birds are warm blooded (endotherms). A bird’s beak and feet are adapted for what they eat and where they live.

Mammals- Warm blooded, have hair, feed their young milk, have a diaphragm and a 4 chambered heart.

Station 4- Biological Processes and Systems

Integumentary System

The primary organ of the integumentary system is the skin.

Function of the skin:

 Protect against infection.  Protect against dehydration.  Excrete waste through perspiration.  Detect touch, pressure, pain, heat and cold.  Make vitamin D through exposure to sunlight.  Help to maintain body temperature.

Skin has two primary layers, the epidermis and the dermis. The epidermis is the outer layer. The exterior layer of the epidermis is made up of dead cells that contain the protein keratin.

The interior of the epidermis contains living cells that continually divide to replace the dead cells. Some of the cells contain melanin, a pigment that gives the skin color and helps protect it from sun damage.

The skeletal system:

 Made up of bones and cartilage that support the body.  Protects internal organs such as the brain, heart etc.  Bone contains marrow that produces blood cells.  Bone stores essential minerals. Red bone marrow produces red blood cells, white blood cells and platelets.

Axial skeleton-skull, vertebral column, ribs and sternum.

Appendicular skeleton- the bones of the arms and legs and structures associated with them.

Muscular System

3 types of muscle tissue:

1. Smooth 2. Skeletal 3. Cardiac

Smooth muscle lines organs such as the intestines and moves food through the digestive system (peristalsis).

Skeletal muscle is attached to and moves the bones.

Cardiac muscle makes up the heart.

Muscle cells that are working will sometimes run out of the oxygen required for aerobic respiration. Muscle cells can make small amounts of energy without oxygen (anaerobic reparation).

The Digestive System

The purpose of the digestive system is to break down food so it can be carried to the cells and used to make energy (ATP).

Digestion begins in the mouth. Chewing breaks food into smaller pieces and the enzymes in saliva begin the chemical process of digestion.

After the food is swallowed, it travels through the esophagus to the stomach where the digestive enzymes break down proteins.

Food then enters the small intestine which is lined with tiny finger-like projections called villi that absorb nutrients. The villi are the link between the digestive system and the circulatory system.

Excess water is absorbed in the large intestine. The large intestine contains the good bacteria, E. coli, that helps you digest your food.

Nervous System The basic unit of structure and function in the nervous system is the neuron, or nerve cell.

Chemicals called neurotransmitters cross a gap called a synapse to carry messages from one neuron to another.

The nervous system can be divided into the central and peripheral nervous systems.

Central nervous system includes the brain and the spinal cord.

The peripheral nervous system carries impulses from the body to the central nervous system. All the nerves in the body except the brain and spinal cord make up the peripheral nervous system.

Parts of the brain:

 Cerebrum – divided into 2 halves. Controls your conscious activities, intelligence, memory, language, muscle movement, and senses.  Cerebellum – balance, posture and coordination.  Brain stem – made up of the medulla oblongata, pons and midbrain. The medulla oblongata controls involuntary activities such as breathing and heart rate.

The medulla oblongata (part of the brain stem) reacts to increased levels of CO2 in your blood stream, stimulating the respiratory system to increase the rate of breathing.

The nervous system works closely with the muscular system.

The Endocrine System

The endocrine system is a system of ductless glands that produce hormones.

Endocrine Glands and Hormones

 Pancreas – secretes insulin which regulates blood sugar levels.  Pituitary –gland that secretes growth hormone  Thyroid – secretes thyroxin which regulates metabolism.  Adrenal glands – produce hormones to prepare body for “fight or flight”  Testes and ovaries – reproductive hormones

Circulatory System

The purpose of the circulatory system is to deliver oxygen and nutrients to the cells, and pick up carbon dioxide and other waste.

Blood includes:

 Red Blood Cells - contain hemoglobin molecules which carry oxygen  White Blood Cells – fight disease  Platelets – cell fragments that help blood clot.  Plasma – liquid part of blood

The heart has 4 chambers. The upper chambers are the atria (atrium is singular) and the lower chambers are the ventricles.

Blood Vessels:

Arteries carry blood away from the heart.

Veins carry blood back to the heart.

Capillaries – tiny vessels that allow for nutrient and gas exchange.

Respiratory System

The purpose of the respiratory system is to take in oxygen and release carbon dioxide.

 The respiratory system includes:

o Mouth and nose o Trachea – windpipe. o Bronchial tubes – passageway from the trachea to the lungs. o Lungs – made up of tiny air sacs called alveoli.

Alveoli – tiny air sacs where gases are exchanged with the bloodstream.

The diaphragm is a muscle that is important in breathing.

When relaxed, the diaphragm is in a dome shaped position. This position decreases the volume of the chest cavity and forces air out of the lungs.

When contracting, the diaphragm contracts, which enlarges the chest cavity allowing, air to rush into the lungs.

Tiny hairs called cilia line the air passages. Mucus traps particles and the cilia beat upward to keep the particles out of the lungs.

Reproduction

Testes – produce the male gamete, sperm cells.

Sperm cells have flagella for locomotion (movement).

Ovaries – produce the female gamete, the egg cell. Egg cells and sperm cells (gametes) have half the number of chromosomes of other cells.

Each month an egg is released by one of the 2 ovaries. If fertilization occurs, it will occur in the oviduct. The fertilized egg, or zygote, will travel to the uterus and implant on the uterine wall. The fetus will develop in the uterus for 9 months.

Excretory System (Urinary System)

The function of the excretory system is to filter waste from the blood and remove it from the body.

The urinary system helps to maintain the homeostasis (balance) of body fluids.

Lymphatic System and Immunity

Immunity defends the body against disease.

The lymphatic system transports tissue fluid (lymph) and filters out and destroys disease-causing pathogens.

The lymphatic system includes:

 The tonsils, which provide protection against bacteria and other pathogens that enter your mouth and nose.  The spleen filters out and destroys bacteria and worn out red blood cells.  Thymus gland  Lymph nodes

White blood cells are important in immunity.

Helper T cells are a type of white blood cell.

The HIV virus, which causes AIDS, attacks helper T cells.

Plant Adaptations

Evolution of plants: All plants probably evolved from green algae (Protists).

Some plants are nonvascular and some are vascular.

Nonvascular plants don’t have vessels, or vascular tissue, for transporting water and nutrients. Nonvascular plants, like mosses, cannot grow very large.

Vascular plants have two main types of vascular tissue, xylem and phloem.

Xylem transports water. Phloem transports food such as glucose.

Xylem and phloem are like tiny straws that transport water and nutrients throughout a plant. Plant roots have 3 functions:

1. Anchor the plant 2. Absorb water and nutrients from the soil. 3. Store food and water.

Plant roots have tiny root hairs that increase the surface area for absorption.

Stems

1. Support the plant. 2. Transport materials between the roots and the leaves. 3. Sometimes store food and water.

Leaves- absorb sunlight and carry out photosynthesis.

Leaves have a waxy covering called a cuticle that reduces water loss.

On the underside of leaves there are tiny openings called stomata for gas exchange and transpiration of water.

Large, broad leaves are an adaptation for capturing sunlight. This is beneficial in regions where many plants compete for sunlight.

Climbing vines are an adaptation for obtaining sunlight.

Desert Plants-Thin leaves or needles are an adaptation that protects the plant’s stored water supply from animals. Leaves that are modified as needles also reduce water loss from transpiration.

Seed Dispersal

A seed consists of a plant embryo and its food supply enclosed in a protective coat.

Many seeds are adapted for dispersal away from the parent plant so they don’t have to compete for water, sunlight, soil, nutrients and space.

A fruit is a ripened ovule of a flower.

It provides protection for seeds and aids in dispersal.

When animals eat fruit, the seeds are not digested and are deposited away from the parent plant.

Seeds are not only dispersed by animals. They are also dispersed by wind, water, and fire.

Cockleburs are seeds that are dispersed by attaching to animal fur.

Mistletoe seeds are dispersed when its fruit is eaten by birds. A coconut is dispersed by dropping in the water. It will eventually reach the shore where it will sprout into a tree.

The cones of the Jack Pine tree will open and release seeds only after the cone has been exposed to the high heat of a forest fire.

Parts of a Flower

A flower is the reproductive structure of flowering plants.

Label the stamen and pistil.

Flowers contain both male and female structures that are involved in producing seeds.

The male part is the stamen which is made up of a filament topped by an anther. Pollen is found on the anther.

The female part of the flower is the pistil. The pistil is made up of the stigma, style and ovary.

In this picture of a day lily you can see the stamen (male parts) surrounding the pistil (female part).

Pollen from the anther, on the tip of the stamen, moves down the pistil where it fertilizes the ovum and produces seeds.

Station 5: Interdependence within Environmental Systems

Abiotic and Biotic Factors

Abiotic factors are all of the nonliving parts of an organism’s environment. Examples: air currents, temperature, moisture, light, and soil.

Biotic factors are all of the living organisms that inhabit an environment.

Matter and energy flow between living organisms (biotic) and the physical environment (abiotic).

Food Chains and Food Webs A food chain is a model that shows how matter and energy move through an ecosystem.

x. Grass  Mouse  Hawk

The arrows show the direction energy is transferred from one organism to the next.

Each step in a food chain is called a trophic level.

Grass  Mouse  Eagle

1st trophic level  2nd trophic level  3rd trophic level

A food web shows more feeding relationships than a food chain.

Autotrophs, Heterotrophs and Decomposers

Autotrophs- (also known as producers) these organisms make their own food.

Examples include plants and algae.

The first trophic level in a food chain will always be a producer (autotroph).

Heterotrophs

Heterotrophs are organisms that feed on other organisms. (They cannot make their own food.)

Heterotrophs that only eat plants are called herbivores.

Heterotrophs that only eat other animals are called carnivores.

Heterotrophs that eat both plant and animal matter are called omnivores.

Autotrophs  Herbivore  Carnivore

Producer  Primary Consumer  Secondary Consumer

1st trophic level  2nd trophic level  3rd trophic level

Decomposers -Break down and absorb dead and decaying plants and animals.

Symbiosis

Symbiosis means living together. 3 types:

1. Mutualism is a symbiotic relationship in which both species benefit.

2. A symbiotic relationship in which one species benefits and the other species is not harmed or benefited is known as commensalism.

3. Parasitism - one member benefits, and the other member is harmed. In a parasitic relationship the organism that benefits is called the parasite. The organism that is harmed is called the host.

Predation is the feeding of one organism on another. Owls are animals that feed on other animals such as mice. The owl is the predator and the mouse is the prey.

Predator-prey relationships help to maintain the health of a population. Predation keeps population sizes within the limits of the available resources.

 If the prey population increases, the predator population may increase as well.

 If the prey population decreases, the predator population will decrease.

 Many predator-prey relationships show a cycle of population increases and decreases over time.

 Predators often have to compete with other species for food.

Energy Pyramids

The trophic levels can be shown in a pyramid.

The producers are always at the bottom of the pyramid.

The amount of energy decreases as you move up the pyramid. Only about 10% of the energy is passed from one trophic level to the next.

Carrying Capacity

Carrying capacity is the maximum number of organisms of a species that an ecosystem can support. The resources in any given environment can only support a certain number of organisms. Food, water and space are resources necessary for survival.

Nitrogen Cycle

Nitrogen makes up about 78% of the atmosphere and is an important element in organisms.

Nitrogen cycles through the living and nonliving parts of the environment.

Plants need nitrogen to make proteins but are unable to directly use the nitrogen in the atmosphere.

Plants rely on nitrogen-fixing bacteria that live in the soil or on their roots to convert atmospheric nitrogen into a form they can use.

When animals feed on plants, they obtain nitrogen.

When plants and animals die and decay, the nitrogen is returned to the atmosphere or the soil.

Phosphorus Cycle

Phosphorus is an element very important to all living things. It is part of the molecules that make up the cell membrane and a part of ATP, the molecule that cells use for energy. Phosphorus is also an important component of DNA and RNA.

Plants absorb phosphorus from the soil.

Consumers get phosphorus by consuming plants.

When organisms die and decompose, the phosphorus is returned to the soil.

Phosphates in the soil wash into bodies of water, settle at the bottom, and become incorporated into sedimentary rock to be released years later by weathering.

Water Cycle

The water cycle is made up of 4 main parts

1. Evaporation- liquid water changes into water vapor. Evaporation is caused by heat energy.

2. Transpiration- is the evaporation of water from the leaves of plants. Stomata are microscopic openings in leaves that control the exchange of gases. The stomata allow the carbon dioxide into the cell which is necessary for photosynthesis. The opening and closing of stomata also regulate the amount of water vapor lost by the plant.

3. Condensation- water vapor in the air cools and changes back into a liquid. Clouds are formed by condensation

4. Precipitation- when water falls back to the earth in the form of rain, hail, sleet or snow. All parts of the water cycle are physical changes. The composition of the water molecule doesn’t change at all.

Carbon-Oxygen Cycle

Carbon and oxygen are elements that are essential to living things.

Carbon and oxygen both cycle through the living and nonliving parts of the environment.

Green plants take in carbon in the form of carbon dioxide and produce oxygen.

Oxygen in the atmosphere is used in the formation of organic matter. Carbon dioxide is released.

Animals take in oxygen and release carbon dioxide.

Animals use oxygen to make energy during cell respiration.

When organic matter decays, carbon dioxide is released into the atmosphere.

Remember that bacteria and fungi are decomposers that help to break down dead and decaying organisms.

Greenhouse Effect

Gases in the atmosphere such as water vapor, carbon dioxide and methane trap heat energy from the sun.

Without these gases, heat would escape back into the atmosphere and the earth would be about 600 cooler.

The greenhouse effect is important. Without it the earth wouldn’t be warm enough for humans to live.

The problem is the enhanced greenhouse effect.

With increasing carbon dioxide emissions from humans the greenhouse effect may also be increasing.

Burning fossil fuels and deforestation are increasing the gases in the atmosphere.

Deforestation is the removal and burning of forests. The burning of trees adds CO2 to the atmosphere and removes the living plants that take CO2 out of the atmosphere. (Remember that plants use CO2 for photosynthesis.).

Theme: Life - Biology is the study of life, why make the theme of a course about life about anything else? Ecology is just one section of biology, where life encompasses the entire course. The basic unit of life, the cell, is then the best place to start and build from there.

Topics to interweave throughout each unit: interdependence, homeostasis, evolution, metabolism and heredity

Scope and Sequence: (following the basic outline of the TEKS as written by the state) also in-line with our current resource, stemSCOPES and the Pearson supplemental aides. The TEKS can be broken into 3 categories, the cell, genetics and ecology. The sequence supports a building of knowledge that allows every unit a tie-in to the previous unit with the last two units serving as the conclusion that joins all otherunits together so that students get a genuine understanding of how all the parts work together to make up the whole. Additionally, these units can serve as a review for the STAAR test.

Each TEK is listed with the Readiness standards in bold. Each unit includes a readiness standard (in some cases two) to serve as the big idea for that unit. .

Category 1: Cells- The Foundation

Unit 1: The Cell B.4- The student knows that cells are the basic unit of all living things with specialized parts that that perform specific functions and that viruses are different from cells. (a) Compare and contrast prokaryotic and eukaryotic cells This unit will include the study of the history of the cell, parts of the cell-organelles and function, and a study of the differences between prokaryotic and eukaryotic cells in terms of complexity. Additionally how to define a virus by comparison. Also a basic overview of the different types of cells and how they are suited to perform specific functions.

Unit 2: Cell Transport B.4-(b) investigate and explain cellular processes, including homeostasis, energy conversions, transport molecules and synthesis of new molecules This unit will focus on how the cell maintains homeostasis but regulating what enters and leaves the cell by active and passive transportation. Important highlights include the introduction of homeostasis, the use of energy by the cell and a very basic overview of the types of molecules the cell needs to function properly

Unit 3: Viruses B.4-(c) compare the structures of viruses to cells, describe viral reproduction, and describe the role of viruses in causing diseases such as HIV and influenza. This unit will focus on the study of what a virus is and how it reproduces. Now that students have prior knowledge of cellular functions, the maintenance of homeostasis and basic metabolism, students can make a comparison as to how cells are different and why diseases such as AIDS and the flu are treated differently when they go to the doctor (antibiotics, immunity, vaccines, etc.) Unit 4: Cell Differentiation B.5- The student knows how an organism grows and the importance of cell differentiation. (a) Describe the stages of the cell cycle (DNA replication and mitosis) and the importance of the cell cycle to the growth of organisms (b) Examine specialized cells (c) Describe the roles of DNA and RNA in cell differentiation (d) Recognize that disruptions in the cell cycle lead to diseases like cancer. This unit will focus on how organisms grow and develop to either remain a single celled organism or become a multicellular organism with specialized tissues and how those tissues know how to become what they are supposed to be. Included would be a basic overview of DNA, what it is and the purpose it serves, structure will come later. Focus on DNA replication and Mitosis supporting this growth and development and the consequences (cancer) of an error happening during this process. Included in this unit will be a more in-depth look at the different types of cells, specifically a microscopic look at the types of cells listed in the TEKS in B.5 (B). Can also touch on the controversy over stem cell research (ethics).

Unit 4: Biochemistry B.9- The student knows the significance of various molecules involved in metabolic process and energy conversions that occur in living things. (a) Compare the structures and functions of different types of biomolecules (carbs, lipids, nucleic acids and proteins) (b) Compare the reactants and products of photosynthesis and cellular respiration in terms of their energy and matter (c) Identify and investigate the role of enzymes (d) Analyze and evaluate the evidence regarding formation of simple organic molecules and their organization into long complex molecules having information such as the DNA molecule for self-replicating life. This unit will focus on the basic structure and function of the biomolecules listed in the TEKS as well as a brief introduction to chemical reactions, as they relate to cell functions such as photosynthesis in plants and cellular respiration in all living organisms. Students will investigate the role of enzymes in chemical reactions. Unit 5: Biological systems (part 1) (B.10) The student knows that biological systems are composed of multiple levels. (a) Describe the interactions that occur among systems that perform the functions of regulation, nutrient absorption, reproduction and defense from injury or illness in animals (b) Describe the interactions that occur among systems that perform the functions of transport, reproduction, and response in plants (c) Analyze the levels of organization in biological systems and relate the levels to each other on the whole system (B. 11) The student knows that biological systems work to maintain balance (a) Describe the role of internal feedback mechanisms in the maintenance of homeostasis. This unit will focus on the major body systems of animal and plants and how those systems work together to maintain homeostasis within the organism.

Category 2: Genetics

Unit 6: The Genetic Code (B.6) The student knows the mechanisms of genetics including the role of nucleic acids (a) Identify the components of DNA, and describe how information for specifying the traits of an organism is carried in the DNA (b) Recognize the components that make up the genetic code are common to all organisms (c) Explain the purpose and process of transcription and translation using models of DNA and RNA (d) Recognize that gene expression is a regulated process (e) Identify and illustrate the changes in DNA and evaluate the significance of these changes (mutations and their effects) Since the basic structure and function of nucleic acids has been covered, this unit will focus how segments of DNA (genes) are expressed via protein synthesis, as well as the consequences of genetic mutations on the individual (to be revisited during the evolution unit).

Unit 7: Heredity (B.6) The student knows the mechanisms of genetics... and the principles of Mendelian genetics (f) Predict the possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid crosses and non-mendelian inheritance (g) Recognize the significance of meiosis to sexual reproduction (h) Describe the techniques such as DNA fingerprinting, genetic modifications and chromosomal analysis are used to study the genomes of organisms This unit will focus on the basic principles of genetics and inheritance, sexual and asexual reproduction and how traits are passed on to offspring (formation of gametes by meiosis). Additionally, the biotechnology behind genetics (karyotyping, DNA fingerprinting, cloning and genetic modification plus the ethical dilemmas surrounding some of those topics) and genetic abnormalities.

Category 3: Evolution, Classification and Ecology

Unit 8: Principles of Evolution (B.7) The student knows the evolutionary theory is a scientific explanation for the unity and diversity of life. (a) Analyze and evaluate how evidence of common ancestry among groups is provided by the fossil record, biogeography, and homologies including anatomical, molecular and developmental (b) Analyze and evaluate scientific explanations concerning any data of certain appearance, stasis and sequential nature of groups in the fossil record (g) Analyze and evaluate the scientific explanations concerning the complexity of the cell This unit will serve as an introduction to the basic principles of evolution but looking at the history of life on earth and how scientists have supported the theory of evolution through evidence in the fossil record, homologies and gene sequences as well as the endosybiotic theory.

Unit 9: Population Genetics (B.7)-(c) analyze and evaluate how natural selection produces change in populations, not individuals (d) Analyze and evaluate how the elements of natural selection, including inherited variation, the potential to produce more offspring than can survive and a finite number of environmental resources, result in differential reproductive success. (e) Analyze and evaluate the relationship of natural selection to adaptation and to the development of diversity in and among species (f) Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation and recombination This unit will focus on the principles of Darwinian evolution, natural selection and population genetics with a focus on the competition for limited resources and carrying capacity of an ecosystem.

Unit 10: Taxonomy (B.8) The student knows that taxonomy is the branching classification based on the shared characteristics of organisms and can change as new discoveries are made. (a) Define taxonomy and recognize the importance of a standard taxonomic system to the scientific community (b) Categorize organisms using a hierarchical classification system based on similarities and differences shared among groups (c) Compare characteristics of taxonomic groups (6 kingdoms) This unit will focus on classification of organisms, why it is important, how it is done and characteristics of major classification groups (6 kingdoms).

Unit 11: biological systems (part 2) (B.11) The student knows that biological systems work to achieve and maintain balance (b) Investigate and analyze how organisms, populations and communities respond to external factors (c) Summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and ecosystems (d) Describe how the events and processes that occur during ecological succession can change populations and species diversity. (B.12) The student knows that interdependence and interactions occur within an environmental system. (a) Interpret relationships (symbiotic) (b) Compare variations and adaptations of organisms in different ecosystems This unit will focus on how organisms interact with one another and their environments, referring back to the biological systems unit previously covered.

Unit 12: Ecology (B.12) The student knows that interdependence and interactions occur within an environmental system. (c) Analyze the energy flow through ecosystems using models (d) Recognize long-term survival of a species is dependent on changing resources (e) Flow of matter through ecosystems (carbon and nitrogen cycles) and consequences of disruption (f) Describe how environmental change can impact ecosystem stability This unit will focus on how organisms interact with their environments and the biological consequences of altering any part of this environment. Ethics- pollution, wildlife preservation, conserving resources

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