Kingdom Plantae. Botany - the study of plants.

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1 Kingdom Plantae Botany - the study of plants.

2 Summary All Plants are autotrophs that produce food by photosynthesis. cell walls composed of cellulose. non-motile eukaryotic multicellular. Plants are loosely organized into 4 groups based on the presence or absence of vascular tissue and seeds.

3 Vascular tissue Vascular tissue - tissue that transports water and sugars throughout an entire plant. Plants lacking vascular tissue are called bryophytes. Plants which have vascular tissue are called tracheophytes.

4 Vascular tissue is made up of xylem and phloem cells. Xylem carries water and minerals to the leaves. Phloem transports food synthesized in leaves throughout the plant.

5 Land plants have a cuticle and stomata (singular stoma). Cuticle is a noncellular layer secreted by epidermal cells to protect cells from drying out. Stomata are pores in the epidermis of a plant, to permit the exchange of gases between the plant and the air around it.

6 Life Cycles of Plants An alternating cycle of both a haploid gamete stage (Gametophyte) and a diploid spore stage (Sporophyte). This cycle is known as the Alternation of Generations Sporophytes produce haploid spores through meiosis (division of the chromosome) that can grow without any fertilization. The spore grows into a gametophyte that produce male and female gametes that can fuse and develop into another sporophyte

7 Alternation of Generations

8 Non-vascular plants: Bryophytes Mosses, liverworts, and hornworts

9 BRYOPHYTES (Phylum Bryophyta) Nonvascular land plants use diffusion and osmosis to transport materials throughout the plant. small in size they grow close to the ground in moist, shaded areas. lack true roots, stems and leaves, they are anchored to the ground by structures called rhizoids. Bryophytes are the only plants to have a life cycle that is predominantly in the haploid gametophyte stage. They produce male and female gametes that require water to allow the sperm to swim to an egg creating a zygote that will develop into a new sporophyte.

10 Tracheophytes Vascular plants: Ferns, gymnosperms, and angiosperms Sporophyte dominated life cycle Seedless (spore bearing) Seeded Plants

11 TRACHEOPHYTES (Phylum Tracheophyta) Tracheophytes have vascular tissues (xylem & phloem). That allow plants to grow much taller, by being able to draw water up through their bodies. Means of reproduction: spores: for club mosses, horsetails, and ferns. seeds: for flowering plants (angiosperms) and conifers (gymnosperms).

12 Seedless Vascular Plants (Ferns) Reproduce by spores, and have an alternation of generations that is dominated by the sporophyte life cycle. (opposite non-vascular) Ferns are the most diverse seedless vascular plant. (dinner to decorations) Life Cycle see page 173 Write a list of ALL key words that come out of the life cycle of the fern. Underline any terminology you have encountered before and note where you have used the word before.

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15 Seed Producing Tracheophytes There are two main groupings for seed producing plants: Gymnosperms (conifers and relatives)- cone bearing plants that have seeds exposed on their cones scales. Angiosperms (flowering plants) plants with protected reproductive structures that have adaptations to increase the likelihood of reproduction.

16 What is a Seed? A seed is a multi-cellular structure containing an embryo and a food source. The embryo consists of a: An immature root An immature shoot One or two seed leaves Seeds have hard protective structures and can survive without water for years. They can also be carried great distances by animals etc

17 Gymnosperms Have all normal plant characteristics Have seeds on their cone scales Most are coniferous trees (pines, spruce, etc )

18 Survival Strategies Reproduction with male pollen and pollen tubes removes the need for moisture. Protective bark prevents water loss Shape helps prevent snow/ice damage, and increases the area for photosynthesis to occur. Needle-like leaves have thick cuticle and sunken stomata to prevent water loss. Do not loose their needles so photosynthesis can begin earlier and they do not need extra nutrients to grow new leaves.

19 Angiosperms (flowering plants) Plants that protect their seeds within the body of a fruit. Make up ¾ s of all plants, including: Trees, shrubs, herbs, grasses, water plants, etc Divided into two large classes based on the number of seed leaves (cotyledons) Monocots one seed leaf (grasses, lilies) Dicots two seed leaves (roses, peas, maple trees)

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22 Diversity and success of the Angiosperms : The angiosperms are the most diverse plant group. They can self-pollinate (clone) or crosspollinate with another plant. Also, this diversity is due to a variety of other factors, such as:

23 1) Presence of specialized structures Plants attract animal pollinators with colour and a supply of food (often nectar) to carry pollen from plant to plant Different flower colors, smells, and shapes attract different pollinators. Eg. Bees can t see red, so they are often on blue or yellow flowers. Flies are attracted to flowers such as stink-cabbage. Many insects see UV spectrum. (See Fig. 6.14, pg. 177)

24 2) Seeds are protected Flowers are sporophytes that do not produce spores. The pollen grains, and the eggs are all that remain of the gametophyte generation. The embryo is enclosed in hard tissue to form a seed. The seed case enables the embryonic plant to survive adverse weather conditions such as drought, hot or arid periods and cold.

25 3) Function of the fruit in seed dispersal Some seeds in fruits are easily dispersed by wind and by water. Eg. Coconut Some fruits are eaten and dispersed by animals. The seed resist digestion and will pass intact in an animal s feces to germinate in a new spot.

26 4) The presence of specialized tissues Some plants possess special tissues and behaviours to help them survive heat, cold, and droughts. Eg. small leaf hairs and sunken stomata help to reduce water loss.

27 Now make like a tree and leave!!