Botany Unit Study Sheet

Botany Unit Study Sheet. Test Date: ______

Five tasks must be performed by plants that live on land. 1. Land plants need to support their leaves and other body parts so that they do not collapse. 2. Land plants need to obtain water and minerals. 3. Land plants need to transport food, water, minerals, and other materials from one part of the body to another. 4. Land plants need to prevent excess water loss to the environment. 5. Land plants need to get sperm cells and egg cells together so that reproduction can occur.

Mosses and Liverworts (Non-vascular Plants)

 Mosses, liverworts, and hornworts are tiny plants that live in moist places. They can be found on rocks, damp tree bark, in the cracks in sidewalks, and the muddy banks of ponds and streams. Because they are small and live in places where water is plentiful, they have few special adaptations for dealing with the challenges of life on land.  These small plants reproduce using spores.  Mosses, liverworts, and hornworts do not have true roots, stems, or leaves. They do have root-like parts, stem-like parts, and leaf-like parts.  Mosses, liverworts, and hornworts belong to the phylum Bryophyta. They are called non-vascular plants because they have no tube-like cells.  Bryophytes do not have tube-like cells that transport nutrients and water from place to place within the plant.  Nutrients and water are transferred from cell to cell (without a system of tubes) in non-vascular plants. This is not a very efficient system, but it is good enough for a very small organism like a moss plant.  The stiff, rigid cell walls of non-vascular plants are the only support structures that they need.  During reproduction their sperm cells swim to their egg cells when they are covered with rainwater or dew.  Gardeners use moss to change the chemical balance of soil for certain plants like rhododendrons and azaleas.  Some mosses are added to soil to improve its ability to retain water.  Sphagnum moss was used by Native Americans as diaper material, and soldiers during the Civil War often used it to treat and bandage wounds because of its natural antiseptic effects.  Deposits of sphagnum moss that has been dead and compressed for a long time is called peat. Peat is used as fuel in some parts of the world. Ferns and their Allies (Primitive Vascular Plants)

 Ferns and their relatives, horsetails and club mosses are the earliest vascular plants to appear on the Earth.  Vascular plants have true roots, stems, and leaves.  Vascular plants have a waxy covering called a cuticle covering their leaves.  Vascular plants have a system of tiny tubes that allow food, water, and other materials like minerals to be transported quickly and effectively throughout the entire body of the plant.  Even though they have tube-like cells, ferns and their relatives reproduce using spores. They need standing water so that their sperm can swim to find eggs to fertilize during reproduction.  Ferns can grow much taller than mosses and their relatives.  Ferns are used as houseplants because of their beautiful, delicate leaves, called fronds.  Fern spores develop on the undersides of fronds. They are formed in structures called sporangia. Clusters of sporangia are called sori. (Many people mistake the sori or spore cases on ferns for a plant disease or insect infestation!)  Some types of ferns in an early stage of development called fiddleheads are used as food.  Horsetails were once used for tooth cleaning because of their abrasive parts.

Gymnosperms & Angiosperms (Advanced Vascular Plants)

 Vascular plants have a transport system made up of interconnecting tube-like cells.  There are two types of vascular tissue: xylem cells and phloem cells.  Other tissues in vascular plants provide strength and places for storage.  Xylem cells carry water and dissolved minerals from plant roots up the stems to the leaves. (Hint for remembering this term: “w” and “x” are near each other in the alphabet.)  Phloem cells carry food that is produced in the leaves down the stems to the roots. (Hint for remembering this term: The “ph” in phloem has the sound of the letter “f.” The word “food” begins with the letter “f.” Phloem cells carry food.)  Vascular plants have roots, stems, and leaves.  Roots anchor the plant into the ground and absorb water and minerals from the soil.  Stems transport materials between the roots and the leaves. Stems also support the leaves of the plant and hold them up to the sunlight.  The leaves produce the food through the process of photosynthesis.  During the process of photosynthesis, carbon dioxide and water are converted to glucose and oxygen. The plant uses the glucose for food, and the oxygen is released into the air.  Most vascular plants reproduce using seeds. (Some more primitive vascular plants such as fern and horsetails reproduce using spores.)  A seed contains an embryo plant, a food supply called a cotyledon, and a seed coat.  Seed plants do not require standing water to reproduce.  The flower is the reproductive structure of the seed plant. The egg and sperm get together in the safety of the flower.  The eggs of the flower are located in the ovary of the flower.  The sperm is found in the pollen.  Pollination is the process by which pollen is carried from the male part of the flower, the stamen, to the female part of the flower, the pistil.  During pollination, pollen lands of the top of the pistil. Each pollen grain creates a tube in which a sperm cell travels until it meets an egg cell, which is located in the ovary of the pistil.  Fertilization occurs when the sperm cell fuses with the egg cell. After fertilization a seed forms.  There are two kinds of seed plants, gymnosperms and angiosperms.  Gymnosperms are plants that have naked seeds. Cone-bearing trees are gymnosperms. The seeds are produced singly in the scales of the cone. (Other gymnosperms are ginkgoes and cycads.)  Angiosperms are plants that have covered seeds. The seeds are covered with a fleshy covering. The seeds develop within the flower’s swollen ovary called a fruit.  Plants are classified as annuals, biennials and perennials according to how long it takes them to produce flowers and how long they live. Annuals live for one season. Biennials complete their life cycles in two years. Perennials live for many years.  The growth of a plant in response to an environmental stimulus is called a tropism. Geotropism (also known as gravitropism) is a plant’s response to gravity. Phototropism is a response to light.

Be sure to know the following diagrams:  Plant parts (leaf, stem, root, fruit, flower)  Flower parts (petal, sepal, pistil, ovary, stamen, anther)  Seed parts (embryo, cotyledon /food supply, seed coat)