SOL Study Book Fourth Grade Life Processes Table of Contents Page 1: Structures of Plants Page 2: Pollination Page 3: Processes of reproduction Page 4: Seedless plants Page 5: Photosynthesis Page 6: Dormancy Page 7: Practice Questions Structures of Plants For many typical green plants there are structures that perform basic functions: Roots anchor the plants and take water and nutrients from the soil A taproot sends a single large root into the soil Fibrous roots spread out into the surrounding soil Plant stems provide support and allow movement of water and nutrients. Veins are bundles of tubes that carry food and water in stems and roots Leaves are the main food making part of the plant. They use energy from sunlight to make food from water and carbon dioxide Flowers make seeds that grow into new plants. The sepals are small leaves that form the housing of the developing flower. Page 1 Pollination A seed is an undeveloped plant with stored food sealed in a protective covering. Seeds can grow into small plants when given water and light. In most plants, seeds are made in flowers. The male sex cells are found in pollen. Pollen is produced by the anther which is part of the stamen. The female sex cells, the eggs, are in the pistil. Pollination can take place when pollen is carried form a flower’s anther to its own pistil or another flower’s pistil. Pollen can be carried from flower to flower by insects, the wind or sometimes birds. Page 2 Process of Reproduction After pollination the next step in the formation of a seed is fertilization. After pollen reaches the pistil, a pollen tube starts to grow. The pollen tube grows down the flower into the ovary. The ovary is a structure containing egg cells. It is the ovary that grows to form a protective fruit. The ovule is like the egg in animals and once fertilization has taken place it will become the seed. A seed develops from a fertilized egg cell into an embryo. Inside each seed is an embryo and a food source. When the time is right, the embryo uses the food to begin to grow its first root, stem, and leaves. Seeds disperse in different ways. -Some plants scatter their own seeds. The protective, fleshy fruits explode to shoot their seeds away from the parent plant. -Some seeds are carried by the wind or water. - Some seeds are carried by animals Page 3 Seedless plants Some plants do not have flowers or produce seeds. Plants such as mosses and ferns use spores. A spore is a cell in a seedless plant. A spore can grow into a new plant. The moss plant has two separate stages in its life cycle. In the first stage, it produces spores. The moss spores grow into moss plants that have male branches and female branches. In the second stage, the male branches produce male sex cells. The female branches make female sex cells. One male and one female sex cell combine to make a fertilized egg. The fertilized egg grows into a thin stalk with a spore case on top. When the spore case opens, the spores are released. Spores that land on damp ground may grow into new moss plants, and the cycle begins again. Page 4 Photosynthesis Green plants produce their own food through the process of photosynthesis Green plants use chlorophyll to produce sugar (food) using carbon dioxide, water, nutrients, and sunlight. Leaves are the primary food producing parts of green plants. Oxygen and sugar are the products of photosynthesis. The sugar is used as food for the plant and oxygen is released into the air. Page 5 Dormancy Viable seeds that do not germinate are said to be dormant. Dormancy can be regulated by the environment or by the seed itself. If a seed is not exposed to sufficient moisture, proper temperature, oxygen, and for some species light, the seed will not germinate. Dormancy can help a plant to survive unfavorable conditions, as in annual plants that pass the cold winter season as dormant seeds. Adaptations help the seeds survive in different types of environments, increasing the chances that they’ll germinate when conditions are right for growth. Some seeds require a period of cold temperatures (winter) followed by warmth (spring) to germinate. Others have hard seed coats that soften up during freeze and thaw cycles. Some seeds have chemicals in their coats that inhibit germination until they are washed away by heavy rains. Some seed coats require “scarring” before they will germinate Page 6 Practice Questions Trees, wild flowers, and grasses are all considered to be — F vascular plants _ G nonvascular plants H woody plants J nonwoody plants The part of a plant cell that gives the cell its green color is the — A nucleus B cytoplasm C vacuole D chloroplast _ One way that mosses and ferns are similar is they both — A are flowering plants B produce spores _ C grow in areas with little rainfall D are dormant during the winter Seeds can lie dormant for many years until — A sunlight causes photosynthesis B food webs are complete C conditions are right for growth D conduction of food occurs Page 7