1. Plants All plants have these things in common: – Plants make their own food – Plants have a cuticle, a waxy coating that covers parts exposed to the sun – Plants have cell walls. – Plants reproduce with spores and sex cells

2. Classification of Plants Plants are divided into two basic groups: vascular and nonvascular. – Nonvascular plants have no “plumbing” to transport water and minerals. – Plants with tissues that can deliver needed materials to their cells are called vascular plants.

3. Nonvascular Seedless Plants Mosses and Liverworts are small. They grow on soil, tree bark, and rocks. They do not have a vascular system. They live in places that are almost always wet. They do not have stems, roots, and leaves.

4. Seedless Plants Mosses usually live together in large groups, covering soil or rocks with a mat of tiny green plants. Each moss plant has slender, hairlike threads of cells called rhizoids. Rhizoids help hold the plant in place.

5. Seedless Plants Liverworts are small, nonvascular plants that usually live in damp or moist places. The life cycle is similar to that of the mosses.

6. Vascular Seedless Plants Ancient ferns, horsetails, and club mosses grew to be very tall. The first forests were made of club mosses that grew to be 40 m high! These plants have vascular systems and therefore they can grow taller than nonvascular plants.

7. Seedless Plants Ferns grow in many places. Most are small although some tree ferns in the tropics grow as tall as 23 m.

8. Seedless Plants You are probably familiar with the sporophyte of the fern. The gametophyte is a tiny plant about half the size of your fingernails. The gametophyte is flat and shaped like a heart. It needs water so that the sperm can swim to the egg.

10. Seedless Plants Seedless vascular plants play important roles in the environment. – They help hold the soil in place and prevent soil erosion. – Ferns are popular houseplants. The fiddleheads are harvested and eaten. – Seedless vascular plants from millions of years ago are now coal.

11. Plants with Seeds There are two types of plants that produce seeds: – Gymnosperms – plants that do not produce flowers. – Angiosperms – plants that produce flowers.

12. Plants with Seeds Seed plants have a two part life cycle like other plants but they differ from other plants in the following ways: – They produce seeds which nourish and protect the young sporophytes – The gametophytes do not live independently of the sporophytes. They are tiny and are always found in the reproductive structures of the sporophyte. – The male gametophytes do not need water to travel to the female gametophytes.

13. Plants with Seeds Pollen is the dust like structure that is carried by the wind or by animals. – The male gametophytes develop inside the pollen.

14. Plants with Seeds A seed develops after fertilization takes place. Fertilization is the union of an egg and a sperm. The seed is made of 3 parts: – A young plant (sporophyte) – Stored food – Tough seed coat

15. Plants with Seeds Plants that reproduce by seeds have advantages over plants that reproduce by spores. – When a seed germinates (begin to grow), the young plant is nourished by the food stored in the seed. – By the time the food has been used, the plant is able to make its own food. – A gametophyte from a spore must be in an environment that it can begin photosynthesis as soon as it begins to grow.

16. Plants with Seeds Gymnosperms – in Greek means naked seed. It is called this because the seed is not enclosed in a fruit. – They are four groups of gymnosperms: Conifers Cycads Ginkgoes Gnetophytes

17. Plants with Seeds The gymnosperm that you are probably most familiar with is the conifer. The name conifer comes from the Greek to “carry cones”

18. Plants with Seeds Conifers have two types of cones – male and female. – The male gametophytes are pollen, the dust like particles that produce sperm – The female gametophyte produces eggs. – Wind carries the pollen from the male cone to the female cone. – The transfer of pollen is called pollination.

19. Male and Female Cones Male cones Female Cone

20. Plants with Seeds Among the gymnosperms, the conifers are the most economically important. People harvest the wood for building and paper products. The resin is used for soap, turpentine, paint, and ink.

21. Plants with Seeds Angiosperms (or flowering plants) are the most abundant plants today. They can be found in almost every environment.

22. Plants with Seeds Flowers help angiosperms reproduce. Some flowers attract animals. When the animals visit different flowers, they may carry the pollen from flower to flower.

23. Plants with Seeds Fruits are also important structures for reproduction in angiosperms. They help ensure that seeds survive as they are transported to areas where new plants can grow. Fruits surround and protect seeds.

24. Plants with Seeds Some have structures that help the wind carry them long or short distances. Others may attract animals that eat fruits and discard the seeds some distance from the parent plant. Prickly burrs are fruits that are carried from place to place by sticking to the fur of an animal.

25. How are these seed types spread?

26. Plants with Seeds Angiosperms are divided into two classes : – Monocots – Dicot The two classes differ in the number of cotyledons in their seeds. A cotyledon is a seed leaf found inside a seed.

28. Plants with Seeds - Importance Angiosperms are important for all animals. They provide food for animals directly and indirectly.

29. Plants with Seeds - Importance They also provide wood and fibers for clothing.

30. Plants with Seeds - Importance They are important for use in medications as well as perfume.

31. Tree Dichotomous Key Use the information we’ve discussed today to identify the plants pictured on the dichotomous key.