chapter 20 protists. question of the day apr 21 eoc review the oldest fossils that have been found...

CHAPTER 20PROTISTS

Question of the DAY Apr 21EOC REVIEW The oldest fossils that have been found are of single-celled organisms. This suggests that life on Earth

A. has become less complex as the atmosphere has changed B. changes in response to mutations but not environment C. mutates in order to adapt to new environments D. has evolved over time from simple to complex organisms

DO NOW Apr 21EOC REVIEW

Draw and label a graph to illustrate a change in finch population if the environment changes to favor large beaks.

DO NOW ANSWERED Apr 21 Recall that this type of change is known as Directional Selection.

AGENDA APRIL 21 OBJECTIVES: Explain the characteristics used to classify

protists.

1. EOC REVIEW QUESTIONS 2. Begin Chapter 20 Protists 3. Review and HOMEWORK

Guided Reading PacketDUE WEDNESDAY Apr 23

CONTINUE TO REVIEW YOUR NOTES EVERY DAY!!!Combined Chapter Test – DATE TBA

20-1: Kingdom Protista Protists are eukaryotes. WHAT FEATURES ARE FOUND IN EUKARYOTES?

Nucleus and membrane bound organelles

Members DO NOT belong to Kingdoms Plantae, Animalia, or Fungi

Most are unicellular. A few consist of hundreds or thousands of cells.

Macrocystic pyrifera

Protists First eukaryotic organisms on Earth were protists

1.5 billion years ago

Very diverse group of organisms

Classified by the way they obtain nutrition.Animallike protists = HeterotrophsPlantlike protists = Photosynthetic protists Funguslike protists = Decomposers

20-2: Animallike Protists - Protozoans

Zooflagellates

Swim using flagella

Absorb food through cell membrane

Reproduce asexually by mitosis and cytokinesisGenetically identical cells

Some perform meiosisNew combination of genetic material

20-2: Zooflagellates

Sarcodines move and feed using pseudopods.Amoeboid movement

Engulf food and other cellsStored in food vacuoles until digested

Reproduce by mitosis and cytokinesis

20-2: Zooflagellates

Ciliates use cilia for feeding and movement.Cilia have same internal structure as flagella

ParameceumCilia arranged in evenly spaced rows

and bundles

Trichocysts protect the cell from dangerRelease spike-like projections

CILIATES Internal Anatomy

Macronucleus – Holds working genes for existenceMicronucleus – Contains a reserve copy of genes

Cilia sweep food into gulletLysosomes digest food

Maintain homeostasis using contractile vacuolesCollect and release water

Can perform Conjugation Exchange of micronuclei with other cells

QUESTION of the DAY APR 22 Viruses are exceptions to the cell theory, but they have some characteristics of living things. What is one of these characteristics?

A. They are made up of many specialized cells. B. They contain genetic material. C. They reproduce by mitosis. D. They contain chlorophyll.

Which statement best explains the patterns seen in these diagrams? A. The organisms at the end of each branch can be found in the

environment today. B. The organisms that are living today have all evolved at the same

rate and have undergone the same kinds of changes. C. Evolution involves changes that give rise to a variety of organisms,

some of which continue to change through time while others die out. D. These patterns cannot be used to illustrate the evolution of extinct

organisms.

AGENDA APRIL 22 OBJECTIVES: Explain the characteristics used to classify

protists.

1. EOC REVIEW QUESTIONS 2. Chapter 20-2 and 20-3 Protists 3. Review and HOMEWORK

WORK ON GUIDED READING PACKET

CONTINUE TO REVIEW YOUR NOTES EVERY DAY!!!Combined Chapter Test – DATE TBA

20-2 Animallike Protists and Disease

Sporozoans do not move on their own Parasites

MALARIA caused by sporozoan Plasmodium Carried by female Anopheles mosquito

African Sleeping Sickness caused by trypanosomes. Bite of a tsetse fly Destroy red blood cells, nerve cells, and can lead to a fatal sleep

20-3: Plantlike Protists

20-2 Trichonympha produce cellulase.Live in guts of termitesDigest wood

20-3 UNICELLULAR ALGAE perform photosynthesis.Contain chlorophyll a, b, and c and accessory pigments

Euglenophytes have two flagella but no cell wallReddish pigment called eyespot helps them find sunlight

20-3: Plantlike Protists

Chrysophytes have gold-colored pigments Cell walls contain the carbohydrate PECTIN

Diatoms produce thin cell walls rich in silicon (Si).

Dinoflagellates are often luminescent.

Photosynthetic Phytoplankton provide food ALGAL BLOOMS deplete nutrients and oxygen

20-4: Red, Brown, Green Algae

RED Algae live deep in the oceans Contain Phycobilins that absorb blue light

BROWN Algae are multicellular Largest and most complex

GREEN Algae are very similar to land plants Cell walls contain cellulose Contain Chlorophyll a and b Store food as Starch

ALTERNATION of GENERATIONSREFER to FIGURE 20-17 PAGE 513Normal Living

Conditions

Haploid cells reproduce asexually

Mitosis produces zoospores

Zoospores genetically identical to the haploid cell that entered Mitosis

Unfavorable Living Conditions

Haploid cells undergo mitosis but release gametes

Two mating types PLUS + and MINUS –

+ and – gametes fuse together

Form a diploid zygote By MEIOSIS, zygote produces

4 haploid cells

Uses of ALGAE

Source of Food Chemicals produced used in medicines and

treatments Industrial uses in plastics, paints, and

electronics Research uses in AGAR plates

20-5 Funguslike Protists Slime Molds recycle organic materials

Reproduce asexually and sexuallyCellular slime molds remain distinct and separatedAcellular slime molds fuse together into plasmodia

large cells with many nuclei

Water Molds feed on dead/decaying matter