2 Plants The plant world is a diverse world. There are plants that trap animals, others that bloom every 30 years, and still others that smell like rotting meat!!!Although you probably don’t see these uncommon plants everyday, all plants, the common and the bizarre, all share some common traits.
3 What is a Plant?Members of the plant kingdom share many characteristics.All plants are autotrophs, or organisms that produce their own food. All plants are eukaryotes that contain many cells. In addition, all plant cells are surrounded by a cell wall.
4 Adaptations for living on Land Most plants live on the land. How is this any different from living in the water?Think about this…Multicellular green algae float around in the ocean. They obtain water and other materials DIRECTLY from the water around them.For plants to survive on land, they must have ways to obtain water and other nutrients from their surroundings, retain water, transport materials in their bodies, support their bodies, and reproduce.
5 Obtaining Water All organisms need water to survive (DUH!) Obtaining water is easy for something like algae, it just diffuses into the cell. Its trickier for plants though…Because most plants live on land, they need adaptations for obtaining water from the soil. Plants also must have ways to obtain nutrients from the soil.
6 Retaining WaterAfter getting water, plants need a means of holding onto it. If they weren’t able to, they could easily dry out due to evaporation.When there is more water in plant cells than the air around it, water leaves the plant and enters the air.One adaptation that helps the plant reduce water loss is the cuticle.Cuticle: Waxy, waterproof layer that covers the leaves of most plants.
7 Transporting Materials A plant needs to be able to transport food, water, minerals, and other materials from one part of its body to another.In general, water and minerals are taken up by the bottom part of the plant while food is made at the top. Even though this is the case ALL plant cells need water, food, and minerals.
8 Transporting Materials (cont.) In tiny plants, materials simply move from one cell to the next.Larger plants need a better method of transport, so these plants have a tissue that transports material called vascular tissue.Vascular Tissue: A system of tube-like structures inside a plant through which water, minerals, and food move.
9 Transporting Materials (cont.) Xylem: Vascular tissue that helps transport water and nutrients up a vascular plant.Phloem: Vascular tissue that helps transport food down a vascular plant.Cambium: Produces new xylem and phloem.
10 SupportA plant must be able to support its own body. Again, this is a simple task for small plants as they have less body to hold up, but can be difficult for larger plants.Large plants’ food making parts need to be exposed to as much sunlight as possible, so they have a series of rigid cell walls and vascular tissue to strengthen and support their bodies.
11 ReproductionAll plants undergo sexual reproduction that involves fertilization.For algae and some plants, this can only happen in a water environment. This is because the sperm cells swim through the water to reach the egg cells.Other plants have adapted in a way that they can reproduce sexually on land.
12 ReproductionMany plants have developed a specific adaptation to allow them to reproduce sexually on land.Pollen: Carries plant sperm cells that allow for sexual reproduction on land.Plants that pollinate create seeds as a result.Seed: A structure that contains a small plant inside.
13 Seeds!As stated previously, seeds contain immature developing plants. Since plants make food through photosynthesis, and plants in seeds don’t receive sunlight, they need some food stored so that they can bust out of their shells.Cotyledon: Leaves in seeds that store food for a developing plant.Germination: When a juvenile plant breaks out of a seed.
14 Classifying PlantsHundreds of thousands of plant species exist in the world today.Scientists informally group plants into two major groups:Nonvascular plantsVascular plants
15 Nonvascular PlantsNonvascular Plants: Plants that lack a system of tubes for transporting water and other materials.Characteristics of nonvascular plants:Low growingNo rootsObtain water and materials directly from their surroundingsBecause they get things directly from their environments, they usually live in damp, shady places.
16 Vascular Plants Vascular Plants: Plants with true vascular tissue. Characteristics of vascular plants:Better suited to live in dry areasCan grow tall due to extra support of vascular systemMore efficient at moving materials through their bodiesOften obtain nutrients and water from soil with roots
17 Vascular PlantsUnlike non-vascular plants, vascular plants have roots to allow them to absorb water and nutrients from the soil, as well as anchor them in place. Roots need to burrow deep into the ground, so they have special tissue to protect them as they do.Root cap: Protective layer around the roots of vascular plants.
18 Complex Life CyclesPlants have complex life cycles that include two different stages, the sporophyte stage and the gametophyte stage.Sporophyte Stage: Stage where plants produce tiny spores that grow into a new organism.Spore: Tiny cell that can grow into a new organism.Gametophyte Stage: Stage where the plant produces sperm and egg cells.