Chapter 23: Eukaryotic Origins

Question 1

Eukaryotes are …

Answer 1

in the domain Eukarya only

Question 2

The structure of Eukaryotes:

Answer 2

• Nucleus with nuclear membrane
• Chromosomes of DNA organized around histone proteins
• Membrane-bound organelles
• Mitochondria (and chloroplasts if photosynthetic)
• Cytoskeleton of microtubules and microfilaments

Question 3

Eukaryotes undergo _____ to reproduce.

Answer 3

mitosis, meiosis, and sexual reproduction.

Question 4

What is the endosymbiont theory?

Answer 4

• Mitochondria and chloroplasts were once free-living
  bacteria
• Engulfed by large host cell, formed chimera cell
• Coevolved together for millions of years and now cannot
  live apart

Question 5

What is the structure of both mitochondria and chloroplasts?

Answer 5

• Two membranes
• Contain their own circular DNA
• Contain their own ribosomes that translate their own proteins
• They divide to create new mitochondria/chloroplasts
• the host cell does not create new mitochondria/chloroplast

Question 6

What is the branch of biology Protist comes from?

Answer 6

• in Domain Eukarya
• Diverse group of organisms that are not plants, not animals, not fungus
• Some are unicellular, some are multicellular
• Some are aerobic(require oxygen), some are anaerobic (do not require oxygen)

Question 7

What are the four ways protist obtain energy?

Answer 7

• Photoautotrophic
• Heterotrophic
• Saprotrophic
• Mixotrophic

Question 8

What are the six monophyletic Eukarya supergroups?

Answer 8

-Archaeplastida
- Amoebozoa
- opisthokonta
- Rhizaria
- Chromalveolata
- Excavata

Question 9

Photoautotrophic:

Answer 9

• Have chloroplasts
• Example: Green algae, red algae, brown algae

Question 10

Heterotrophic:

Answer 10

• Obtain food from the environment
• Phagocytosis
• Example: Amoeba

Question 11

Saprophytic:

Answer 11

• Absorb nutrients from dead/decaying matter
• Example: Slime Mold

Question 12

Mixotrophic:

Answer 12

• Both photoautotrophic and heterotrophic
• Example: Euglena

Question 13

Describe the 3 types of motility protist have:

Answer 13

• cilia, hair-like structures
• pseudopod, tentacle crawling {venom symbiote crawling from spiderman 3}
• flagellum, one single propeller (ex. sperm tail)

Question 14

Protist reproduction includes:

Answer 14

• asexually, binary fission and budding
• sexually
• Some are parasitic and require a host to reproduce

Question 15

Protist are primary producers of

Answer 15

• Phytoplankton
• Zooplankton eat phytoplankton, larger organisms eat zooplankton, etc.

Question 16

Up to __% of oxygen can be attributed to protists

Answer 16

25

Question 17

_________ are photosynthetic dinoflagellates that form symbiotic
relationship with coral polyps.

Answer 17

Zooxanthellae

Question 18

________ protists obtain nutrient from dead organisms and feces

Answer 18

Saprophytic

Question 19

Protists recycles __________ back into the soil and
water. These are limiting nutrients for plant life.

Answer 19

nitrogen and other inorganic nutrients

Question 20

Protist and fungi are ____ as they absorb nutrients from dead organisms and feces making them an ecosystem service.

Answer 20

nutrient recyclers.

Question 21

3 protists as human pathogens?

Answer 21

• Malaria - Unicellular protist, infects red blood cells
• African Sleeping Sickness - Unicellular protist, changes extracellular glycoproteins each time it reproduces, attacks red blood cells, eventually leads to death
• Giardia - Flagellated unicellular protist, infects small intestine

Question 22

3 protists as plant pathogens?

Answer 22

• Downy mildew - Causes discolored, wilted leaves
• Potato blight - Causes stems and leaves to decay