Chapter 11

1. Chapter 11 Protists

2. Chapter 11: Section 1 Objectives • Describe the characteristics of protists. • Describe 4 ways that protists get food. • Describe 3 ways protists reproduce.

3. Protists • What are protists? • Members of Kingdom Protista • They come in a range of sizes • Some are poisonous • Very diverse group • Protista is a very diverse group with few traits in common. • What does diverse mean?

4. General Characteristics • Very diverse. • Have few traits in common. • Can be uni-cellular, multi-cellular, or live in colonies. • Can be producers, consumers, or decomposers. • All are eukaryotic. • What does this mean about their cells?

5. General Characteristics • Related more by how they differ than by how they are similar. • Less complex than other eukaryotic organisms. (do not have specialized tissue). • Fungi, plants, and animals have specialized tissues that have specific functions.

6. Protists and Food • Protists get food in many ways: • Some eat organisms (consumers) • Some make their own food (producers) • These protists contain chlorophyll and get their food through photosynthesis. • Others eat dead or decaying organisms (decomposers)

7. Producers • Produce their own food through photosynthesis. • Have specialized structures called chloroplasts in their cells. • Chloroplasts capture energy from the sun. • Plants use this same process to produce food.

8. Finding Food • Some protists must get their food from the environment. • Heterotrophs are organisms that cannot make their own food. • These organisms get food through 1 of the following methods: • Eat other organisms • Eat parts/products of other organisms • Eat remains of organisms

9. Finding Food • Many protist heterotrophs eat small living organisms, such as bacteria, yeast, or other protists. • Some protists can get food in more than one way. • For example, some species of slime molds are decomposers and consumers.

10. Finding Food • Some protist heterotrophs are parasites. • A parasite invades another organism to get the nutrients that it needs. • An organism that a parasite invades is called a host. • Do parasites cause harm to, benefit, or cause no harm to their host?

11. Producing Protists • Kingdom Protista is a very diverse group. • Like all living things, protists reproduce. • Most protists reproduce asexually. • These offspring are identical to the parent. • Traits are pulled from only one parent. • Like bacteria, they reproduce by binary fission. • Some reproduce by sexual reproduction.

12. Section 2: Objectives • Describe how protists can be organized in 3 groups based on shared traits. • List an example of each of the protist groups.

13. Kinds of Protists • Protists are hard to classify because of so much diversity in the group. • One way that protists are grouped is based on shared traits. • Scientists are constantly discovering new traits/characteristics about protists so they are hard to classify.

14. Kinds of Protists • Protists are placed into 3 groups: • Producers • Heterotrophs that can move • Heterotrophs that can’t move • These groups do not show how protists are related to each other except for 2 traits.

15. Protist Producers • Protist producers use the sun’s energy to make food through photosynthesis. • These protists are known as algae. • All algae have the green pigment chlorophyll. • Most algae have other pigments that give them color. • Almost all algae live in water.

16. Protist Producers • Multi-cellular algae live in shallow water along the shore. • Free-floating uni-cellular algae are called phytoplankton. • These algae cannot be seen without a microscope. • These algae usually float near the water’s surface. • These produce much of the world’s oxygen. • Why would these algae need to live in shallow water?

17. Red Algae • Most of the world’s seaweed is red algae. • Most live in tropical oceans attached to rocks. • These contain chlorophyll, but a red pigment gives them their color. • This red pigment allows them to absorb light that filters into deep water.

18. Green Algae • This is the most diverse group of protist producers. • Chlorophyll is the main pigment in their cells. • Most live in water or most soil. • Can be uni or multi-cellular. • Individual cells of some species live in small groups called colonies.

19. Ch. 1 Sec. 1-2 Pop Quiz • 1) List 3 general characteristics of protists. • 2) _______ capture energy from the sun. • 3) What are heterotrophs? • 4) Some heterotrophs are ________. • 5) Most protist reproduce ________. • 6) List the 3 groups that protists are placed in • 7) Free-floating uni-cellular algae are called ____________. • 8) _______ is the most diverse group of protists.

20. Brown Algae • Found in cool climates. • Attach to rocks or form large floating masses. • Contain chlorophyll and a yellow pigment. • Form very large masses that can grow up to 60 meters. • Produce food through photosynthesis.

21. Diatoms • Single-celled. • Found in both salty and fresh water. • Get their energy through photosynthesis. • Make up a large percentage of phytoplankton. • Cell walls of diatoms contain a glasslike substance called silica.

22. Dinoflagellates • Single-celled. • Most live in salty water. • Have 2 whip-like strands called flagella. • Use these strands for movement. • Most are producers. • Some are consumers and decomposers.

23. Euglenoids • Single-celled protists. • Most live in fresh water. • Use their flagella to move through the water. • Most are producers. • When there is not enough light to make food, they can be heterotrophs.

24. Heterotrophs That Can Move • Some heterotrophs have special traits that allow them to move. • Others cannot move on their own. • Those that can move are usually consumers or parasites. • These mobile protists are called protozoans.

25. Amoebas • Found in both fresh and salt water. • Look shapeless but are actually highly structured cells. • Eat bacteria and small protists. • Others are parasites that depend on host organisms. • Have pseudopodia (false feet) that help them move around.

26. Heterotrophs That Can’t Move • Not all protist heterotrophs have features that help them move. • Some can move only for a short period in their life. • Many are parasites and absorb nutrients from their host.

27. Section 3: Objectives • Describe characteristics of fungi. • Distinguish between 4 main groups of fungi. • Explain how lichens affect the environment.

28. Characteristics of Fungi • Eukaryotic heterotrophs • Rigid cell walls • No chlorophyll • They are so different from other organisms that they are placed in their own kingdom. • Come in a variety of shapes, sizes, and colors.

29. Food for Fungi • They are heterotrophs but cannot catch or surround food. • Must live on or near their food supply. • Most fungi are decomposers. • Other fungi are parasites. • Some fungi live in mutualism with another organism. • What is mutualism?

30. Microscopic Traits • Multi-cellular fungi are made up of chains of cells called hyphae. • The opening between cells allow cytoplasm to move freely between cells. • Most of the hyphae that make up fungus grow together to form a twisted mass called mycelium.

31. Making More Fungi • Can be sexual or asexual. • Spores are reproductive cells that are protected by a thick cell wall. • Spore = reproductive cell of fungi • Spores are light and easily spread by the wind. • When growing conditions are favorable, fungi will grow where the spores land.

32. Kinds of Fungi • Thread-like fungi • Club fungi • Non-mushroom fungi • Imperfect fungi

33. Thread-like Fungi • A mold is a shapeless fuzzy fungi. • Mold belongs to threadlike fungi. • These fungi reproduce asexually.

34. Club Fungi • These are umbrella shaped mushrooms. • These fungi reproduce sexually (spores). • These fungi have “gills” under the umbrella that allow spores to be dispersed.

35. Non-mushroom Fungi • Mushrooms are not the only club fungi. • Bracket fungi grow outward from trees and form small shelves or brackets. • They attack crops such as corn and wheat.

36. Imperfect Fungi • Includes all species of fungi that do not fit into other groups. • Most are parasites that cause diseases to plants and animals. • Some forms are useful: • Penicillium: source of the antibiotic penicillin

37. Lichens • A lichen is a combination of a fungus and algae that grow together. • The algae live in protective walls of the fungus. • These can grow on rocks because they need only light, minerals, and air to grow.

38. Ch. 11 Sec. 3 Pop Quiz • 1) List 3 characteristics of fungi. • 2) How do fungi get food? • 3) List and describe 4 different groups of fungi. • 4) What is a spore? • 5) Where do algae live in lichens?