Genetics/Genetic Disorders, Evolution, & Classification Review Sheet Test 2013-14

Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______Genetics/Genetic Disorders, Evolution, & Classification Review Sheet Test 2013- 14 Aside from these genetics questions, you can use Review sheets & Genetics Problem Sets from the Unit 8/9 webpage (answer keys are also on the same page).

Genetics 1. What is a gamete? A sex cell used for reproduction with ½ the regular # of chromosomes as an organism’s regular body (somatic) cells

2. How many chromosomes are found in a human gamete? 23

3. How does the number of chromosomes in a human gamete compare to the number of chromosomes in a human body (somatic) cell? Why is this important? a gamete has ½ the regular # of chromosomes as an organism’s regular body (somatic) cells so that when fertilization occurs, the offspring has the correct # of chromosomes (& not too many)

4. What is an allele? different forms of a gene for the same trait (ex. brown/blonde hair)

5. Compare/contrast dominant & recessive alleles. Dominant alleles: “block” the expression of the recessive allele, can be expressed (in the phenotype) when part of a homozygous dominant genotype or a heterozygous genotype, are represented by a capital letter Recessive alleles: are “blocked” by the dominant allele, can be expressed (in the phenotype) ONLY when part of a homozygous recessive genotype, are represented by a lower-case letter

6. How many alleles for a single trait do we get from each parent? 1 from each parent (So, we have a total of 2 alleles for each trait.) Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______7. What is genotype? The allele combination an organism has for a trait. Written as a combination of 2 letters, ex. TT, Tt, tt.

8. What is phenotype? How the genotype is expressed/”seen” (physically, physiologically, behaviorally). Usually given as an adjective (ex. purple, tall, color-blind)

9. What does it mean when an organism’s genotype is homozygous? How is this represented? Homozygous means that the organism has 2 of the SAME alleles for a trait. This is represented by using 2 of the same case letters, ex. TT or tt.

10. What does it mean when an organism’s genotype is heterozygous? How is this represented? Heterozygous means that the organism has 2 of DIFFERENT alleles for a trait. Represented by using 1 letter of each case, ex. Tt.

11. Why must an organism that shows the recessive trait be homozygous for that trait? B/c if it had even one dominant allele, that dominant allele would “block” the recessive allele from being expressed/”seen”

12. The trait we see (ex. flower color, hair color, etc.) is due to the __protein______that is made as a result of transcription and translation.

13. In a Punnett Square, the letters along top & side represent _the alleles in each parent’s gametes (sperm or eggs)______. Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______

14. In a Punnett Square, the boxes represent __the possible genotypes of the offspring resulting from the cross______.

15. A female has which 2 sex chromosomes? ____XX____ A male? ____XY____

16. Which parent’s chromosomes determine the sex of the offspring? Explain your reasoning. Dad’s (male) b/c mom always gives an X to the offspring. If dad gives an X, the offspring is a girl. If dad gives a Y, the offspring is a boy.

17. What is codominance? When 2 alleles are equally dominant and both traits show up in the heterozygous offspring. Represented by 2 capital letters. Ex. AB blood type in humans

18. What is meant by multiple alleles? Give an example of a trait that is controlled by multiple alleles. Even if a gene has multiple alleles, a person can only have how many of those alleles? Multiple alleles are when there are more than 2 different genes (alleles) for a trait. Human blood types are controlled by multiple alleles (There are 3 alleles: A, B, & o). A person can ONLY have 2 alleles even if a gene has more than 2 versions b/c a person gets 1 allele from Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______mom & 1 from dad. Ex. A human can have an AB genotype for blood type, but not ABo.

19. __(Males/Females)_ will have only 1 allele for traits carried on the X chromosome. b/c a male only has 1 X chromosome... the Y doesn't carry an allele.

20. When making a Punnett Square for ___sex-linked______traits (such as hemophilia), you must consider the sex chromosome (X or Y) & gene it carries (shown as superscript/exponent) together as a unit… ex. XG.

21. What does it mean that a female is a carrier for a (recessive) X-linked trait? If a female is a carrier for an X-linked trait, she has a heterozygous genotype, ex. XGXg. She, herself, does not have the trait/disorder b/c she has the dominant "normal" allele, but she does carry the recessive "affected" allele that can be passed on to her offspring. 22. Sex-linked traits that are controlled by recessive alleles on the X-chromosome are more likely to show up in _____(males/females)_____. Why? b/c a male only has 1 X chromosome... the Y doesn't carry an allele. So, while a female can have 3 genotypes: XGXG, XGXg, XgXg (2 of which do not cause her to be affected b/c they contain at least 1 dominant allele), a male can only have 2 genotypes: XGY & XgY (only 1 of which does not cause him to be affected b/c it contains the dominant allele).

23. KNOW how to make and interpret Punnett Squares for dominant/recessive, X- linked and human blood types (codominant and multiple alleles). Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______24. In pea plants, purple flowers are dominant to white flowers. Is it possible for two purple flowers to have a white-flowered offspring? Explain your reasoning/use a Punnett Square to show your thinking. If both plants are heterozygous, they would be purple, but carry the recessive white allele. If both pass on the recessive allele, the offspring would be white.

25. A woman is colorblind (XcXc). She marries a normal man (XCY). Can they have a son that is normal? Explain your reasoning/use a Punnett Square to show your thinking. Since colorblindness is X linked & recessive and the mother has the disorder (is XcXc), she can only give a Xc allele… the dad gives the son the Y allele… So, all sons would be colorblind (is XcY)

XC Xc XH Xc

Xc Y Xc Y Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______

Evolution 26. Which gas was not part of Earth’s early atmosphere? oxygen

27. Define evolution. theory that species have changed gradually over time (as a result of the changes in allele frequency due to natural selection)

28. What are the 4 mechanisms (causes) of evolution? Give a brief description of each. a.1. migration: gene frequencies change as individuals move in or out of the population

a.2. genetic drift: change in gene pool of small population that takes place by CHANCE

a.3. mutation: random change in DNA sequence of a gene (can change amino acid sequence & protein coded for… can change the way the trait is expressed)… not all mutations matter in evolution, to matter they must be heritable (in gametes)

a.4. natural selection: organisms with variation best suited for environment tend to survive, & reproduce (“survival of the fittest”)… more offspring will have favorable adaptation than before. …acts on individuals, but causes evolution of a population (by changing the allele frequencies in gene pool).

29. Describe Jean-Baptiste Lamarck’s explanation for how evolution occurs. What was his theory called? Give an example. “Theory of Acquired Characteristics”  acquired traits are passed on… Exà giraffe acquired longer neck by reaching for leaves on higher branches & passed on to offspring; Ex. Tattoo passed to offspring… Experimentation did not support Lamarck’s theory.

30. What are Darwin’s 4 main points related to his “Theory of Natural Selection”? Give an example of each. a.1. Overproduction of offspring: more offspring are produced than generally survive to ensure that at least some will survive long enough to reproduce & pass on genes Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______a.2. Struggle to survive (competition): more organisms than resources to go around leads to competition (for food, water, shelter, mates, light, nutrients, etc.).

a.3. Variation within population: there are differences in traits in a population… Individuals w/ variations for traits adaptive for their environment have a better chance of survival, & thus, leave more offspring… What causes variety?  sexual reproduction, crossing over during meiosis, arrangement of chromosomes during meiosis, mutations… Variations can be adaptations & are NOT a response to the environment, they just happen to be “useful” when environment changes.

a.4. Successful reproduction (“natural selection”): Those organisms best suited for environment tend to survive, reproduce, & pass on genes (“survival of fittest”) leading to more offspring that have the favorable adaptation than before.

31. What are the 4 things that can cause variations amongst the individuals of a population? Give a brief description of how each causes variation. a.1. sexual reproduction: combining alleles from 2 genetically different parents (instead of just copying DNA, like in asexual reproduction)

a.2. crossing over during meiosis: pieces of chromosomes are swapped during crossing over during prophase 1 of meiosis a.3. a rrangement of chromosomes during meiosis: how chromosomes align during metaphase 1 or 2 of meiosis determines which chromosomes go into which gametes (& in which combinations)

a.4. mutations: random change in DNA sequence of a gene (can change amino acid sequence & protein coded for during translation) which can change way trait is expressed

32. Darwin did not have knowledge of ___genetics______.

33. Who came up with a similar explanation for evolution as Darwin? Wallace Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______34. What is a homologous structure? Give an example. Homologous structures are structures that are similar in structure (and sometimes function) but with some modifications. They are evidence of a common ancestor and of divergent evolution (in which the organisms are becoming more different). Ex. human arm/hand, whale flipper, dog’s front leg, bat wing, bird wing, crocodile’s front leg  all have similar bone structures & patterns (w/ some modifications)

35. What is an analogous structure? Give an example. Analogous structures have similar functions, but not structures due to similar environment/use. Organisms do NOT have common ancestor, but have structures that are becoming more similar (convergent evolution) due to similar usage. Ex. insect wing & bird wing  both are used to fly, but insect wings don’t have bones while bird wings do

36. What is a vestigial structure? Give an example. Vestigial structures are structures with decreased size or function. They often have no apparent use in the present organism. Vestigial structures are evidence that an organism has changed. Ex. hip bones in whales (evidence of the fact that whales had ancestors that had legs & walked) & appendix in humans (apparently used when our diets were more plant-based & less animal-based).

37. How do embryos, provide evidence for evolution? When looking at embryos of organisms… the early stages are very similar, which is evidence that they inherited same basic body plan from a common ancestor. In the later stages there is more distinction… the greater the # of similar stages, the more closely related the organisms are (& the more recently they split from their common ancestor). Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______

38. How does biochemistry (DNA, amino acids, proteins, etc.) provide evidence for evolution? Similar organic compounds are coded for by similar DNA (ex. proteins). DNA is the most reliable form of evidence. If 2 very different species share (large amounts of the same) DNA it is evidence of common ancestry. The higher %, more closely related (ex. human & chimpanzees 98% similar; humans & other mammals 80% similar)

39. Are adaptations a response to the environment (a choice) or do they just happen to be “useful” when the environment changes? Explain your reasoning. Adaptations are NOT a response to environment! They just happen to be “useful” when environment changes. Certain features are not developed “in order to” adapt to change in env…. Variation already exists in population & certain variations become useful when env changes… The organisms w/ the best-suited variations survive & produce offspring while others die before they can reproduce… in this way a population/species becomes adapted to its environment… 40. ___Indirect evidence______for evolution includes the fossil record, comparative anatomy, comparative embryology, & comparative biochemistry.

41. ___Direct evidence______for evolution is evolution we can “see”, such as antibiotic-resistant bacteria and pesticide-resistant insects.

Classification

42. What “nickname” was Carolus Linnaeus given? Discuss Linnaeus’ classification system. Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______ “The Father of Modern Taxonomy”

 Classification system in which the 2 main groups, plants & animals, were known as kingdoms…

 Also used smaller, more specific groups like genus (a group of similar species) and species (organisms that can mate w/ each other & produce fertile offspring)

 Gave organisms names that described their traits

o Naming system is known as “binomial nomenclature”

. Names have 2 parts

 1st part is the organism’s genus (similar to a person’s last name)

 2nd part is the organism’s species (similar to a person’s 1st name)

43. What are the rules for writing scientific names? Give examples.

 Genus is 1st & always capitalized

 Species is 2nd, written in all lowercase letters, & descriptive

 When written/typed italicized or underlined when hand-written

o Examples Homo sapiens; Homo sapiens

44. In the current classification system, organisms are classified by ____? Evolutionary relationships

45. When we classify organisms, we start with __ very broad/general______characteristics down to ____very narrow/specific______characteristics. Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______

46. Show the relationship between the 3 domain, 5 kingdom, & 6 kingdom systems of classification.

(Eu)bacteri 3 Domain system Archaea Eukaryota (Eukarya) a 6 Kingdom (Eu)bacteri Protista Archaea (Archaebacteria) system a fung plan animalia 5 Kingdom Monera i tae system

47. List the 8 taxa (classification groups) used to classify organisms from broadest/most general to narrowest/most specific. What saying can you use to help you remember? Relate each group to continents, countries, etc.

 Domain Did Continent (North America)

 Kingdom King Country (USA)

 Phylum Phillip State (CT)

 Class come County (Fairfield)

 Order over Town (Darien)

 Family for Neighborhood (Noroton Heights)

 Genus good Street (High School Lane)

 Species spaghetti? House # (80) Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______48. What is the relationship between taxonomic levels (classification groups)?

 From domain down, each level has a new set of criteria (characteristics) that must be shared

 As go down levels, exclude organisms that don’t share the next trait.

 The more closely related 2 organisms are, the more levels of classification (taxa) they share

 Once an organism shares a more specific taxon (lower group) it MUST share the more unifying taxa (higher groups)

o Ex. organisms in the same species (lower taxa) MUST belong to the same class (higher taxa)

o Ex. organisms in the same class (high taxa) do NOT NECESSARILY belong to the same species (lower taxa)

49. Characteristics of each domain/kingdom? Use the chart. 3 Domain Archaea (Eu)bacteria Eukaryota (Eukarya) system

6 kingdom Archaea (Eu)bacteria Protista Fungi Plantae Animalia system (Archaebacteria)

5 kingdom Monera system

Prokaryotic/  prokaryotic  Prokaryotic  eukaryotic  eukaryotic  eukaryotic  eukaryotic eukaryotic

Unicellular/  unicellular  unicellular  Mostly  Mostly  multicellular  multicellular multicellular unicellular multicellular

feeding  Heterotrophic  Heterotrophic  Heterotrophic  Heterotrophic  autotrophic  heterotrophic or autotrophic  autotrophic  autotrophic (digest food (photosynthesi outside & s) absorb nutrients) Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______other  Older, less  modern, more  can be plant-  Cell walls  cell walls  no cell wall characteristic complex complex like, animal- (made of (made of s bacteria bacteria like, fungus- chitin) cellulose)  live in  evolved from like  decomposers &  produce extreme Archaea parasites oxygen environments  most common (very hot, bacteria very cold, acidic, salty,  very diverse etc.)  free-living or pathogenic

examples  bacteria that  Staphylococcu  Amoeba  mushrooms  mosses  invertebrates live in salt s  Paramecium  mold  ferns o insects lakes  E. coli  Euglena  yeast  trees o worms  bacteria that  cyanobacteria (unicellular) o sponges live at  algae  grasses o corals hydrothermal  shrubs vents  vertebrates  land-based plants o fish o birds o amphibians o reptiles o mammals

50. What is a dichotomous key?

 A tool used to help classify/identify objects by using pairs of opposing statements or asking a question with 2 possibilities.

51. What are the 2 formats/methods for making a dichotomous key?

a. List

a.i. How many pairs of characteristics/statements will you have compared to objects?

a.i.1. One less pair of characteristics than objects… ex. 5 objects  4 pairs or characteristics/statements Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______b. Branching/tree diagram

b.i. How many objects should be in each of the final boxes?

b.i.1. (in final box MUST have only 1 object)

52. When making a dichotomous key always use __paired, opposing__ statements/questions. Give an example. green?/not green?

53. What type of characteristics/traits do we usually use when making a dichotomous key? PHYSICAL characteristics/traits Give an example. color, shape, # of toes

54. When making a dichotomous key what shouldn’t you do?

a. Usually DON’T use job/function

b. DON'T use a characteristic that changes

c. Ideally, DON'T repeat a trait… Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______

55. Make a dichotomous key for the sporting equipment below:

EXAMPLE (LIST FORMAT)

Sporting Equipment

1a worn on feet…………… go to 2 1b not worn on feet…….go to 4

2a laces……………………….go to 3 2b no laces………………….M

3a wheels……………………N 3b no wheels……………….J

4a handle…………… ………go to 5 4b no handle………………H

5a oval head……………….L 5b no oval head………….go to 6

6a L-shaped…………………I Name ______ANSWER KEY______Date ______Mrs. Geithner-Marron (Bio 200) Period ______6b not L-shaped…………… K