CH. 28: Protists

1. Fossil evidence of eukaryotes dates back to

1.5 bya

Which of the following organisms lacks chloroplasts?

A)KelpB)DinoflagellatesC)NoriD)DiatomsE)NONE OF THE ABOVE LACK CHLOROPLASTS

1. Analyze the following statements and choose the one that most accurately supports the endosymbiotic theory.

Antibiotics that inhibit protein synthesis in bacteria can have the same effect on mitochondria.

12. When food is scarce, cells of this organism communicate with each other to form a multicellular slug.

Cellular slime molds

3. Examine the life cycle of cellular slime molds, and determine which feature affords the greatest advantage for surviving food shortages.

Cellular slime molds produce spores when starved.

11. Which is most likely the ancestor of animals?

Choanoflagellates

10. Choose all of the following that are photosynthetic

Diatoms, Dinoflagellates

How might we explain the differences between RNA polymerase II between red algae and green algae, despite genetic similarity between chloroplasts?

Different host cells engulfed the same bacterial symbiont.

2. DNA is not found in this organelle

Endoplasmic reticulum

In a plasmodial slime mold, what behavior occurs in the plasmodium "form"?

Feeding

2. Determine which feature of the choanoflagellates was likely the most significant for the evolution of animals?

Flagellum with a funnel-shaped, contractile collar also found in sponges

What structure would be most diagnostic of a member of the stramenopila?

Having a flagellum that has "furry" extensions on it.

What structure was ultimately responsible for the establishment of a nuclear envelope?

Infoldings of the cell membrane gradually increased to allow the cell to achieve larger volumes. Eventually partitioning of the nucleus provided additional control over gene expression.

The kinetoplastids have a conspicuous organelle for which they are named. What is the role of the kinetoplastid?

It is their mitochondrion.

Plasmodium is an apicomplexan which causes which serious disease, a leading killer worldwide?

Malaria

Which one of the following statements about protists is incorrect?

Protists are prokaryotic organisms.

9. Choose all of the following that exhibit an alternation of multicellular generations.

Red algae

Choanoflagellates are most closely related to which of these organism

Sponges

Which of the following statements most accurately reflect the problems with classification using the category of "protists"?

The grouping is paraphyletic because it excludes groups, such as plants, which are descendents from ancestors of green algae.

What evidence is there for the endosymbiotic origin of chloroplasts and mitochondria?

The structure of DNA in chloroplasts and mitochondria is circular and without centromeres and telomeres.

What is the evidence that diplomonads such as Giardia once had mitochondria but lost them secondarily?

They have in their genome genes which are very similar to those found in mitochondria.

The namesake for alveolata is the collection of membrane stacks just under their cell membrane. What is their likely purpose?

They're probably used for membrane transport activities.

Why is it so hard to develop a vaccine against Chagas disease (caused by trypanosomes which are spread through tsetse fly bites)?

Trypanosomes have thousands of variable antigen genes from which to select, making it hard to develop an antibody which will consistently bind to them

How are protists valuable for understanding the evolutionary origin of mitosis?

Various intermediary strategies may be viewed as "missing links" that help define the spectrum of events which culminated in the events we see in more advanced eukaryotes.

The Stramenopila includes the

brown algae.

7. If a cell contains a pellicle, it

can change shape readily

Paramecium is a common

ciliate

Which of the following produces a unique carbohydrate called chrysolaminarin?

diatoms

The poisonous "red tides" result from blooms of

dinoflagellates.

The White Cliffs of Dover are made up largely of

foraminifera.

5. Trypanosomes are examples of

kinetoplastids.

4. Both diplomonads and parabasalids

lack mitochondria.

6. The function of the apical complex in apicomplexans is to

penetrate host tissue.

8. Stramenopila are

small hairs on flagella

3. The products of budding are ---

two cells, one of which is smaller than the other.