Chapter 27

Question 1

How does Mitosis and Meiosis work in humans?

Answer 1

Mitosis is cell growth and repair and Meiosis is the production of gametes.

Question 2

What is ploidy?

Answer 2

The number of chromosome sets, haploid cells (N) have one copy (only gametes in humans), diploid (2N) have two (most cells in humans), polyploidy have more than two (3N 4N 6N)

Question 3

What is endosymbiosis?

Answer 3

mitochondria are present in all eukaryotic cells and that the
engulfed aerobic heterotrophic bacteria provide the host cell with ATP.

Question 4

How do endosymbiosis relationships end up with them becoming one organism?

Answer 4

Two organisms living together with one inside the other, overtime they evolve into one being and gain a mitochondria and/or chloroplast.

Question 5

According to the endosymbiosis theory, how does a protist gain a chloroplast?

Answer 5

A cyanobacterium is engulfed by the protist, forming a symbiotic relationship, gaining a chloroplast.

Question 6

How do chloroplasts work and who has them?

Answer 6

Plants and plant-like protists, the chloroplast converts light into sugar.

Question 7

What evidence is there to support the endosymbiosis theory?

Answer 7

Mitochondria and chloroplast contain own ribosomes and have double the membranes, have separate genomes (rings of DNA, code for specific proteins), divide by binary fission, and endosymbiosis relationships exist today.

Question 8

What characteristics do protists have?

Answer 8

Eukaryotic, mostly unicellular but complex,
and live in moist environments.

Question 9

What is the difference between being colonial and multicellular?

Answer 9

Colonial means all cells do the same task and look the same, and multicellular means the cells are different and specialize in different things.

Question 10

What are protists in terms of taxonomy?

Answer 10

They are paraphyletic because they do not share the same common ancestor.

Question 11

What are some ways that protists get nutrition?

Answer 11

They can photosynthesize, ingest, and absorb. They can also be parasitic, symbiotic, or free-living.

Question 12

How can protists reproduce?

Answer 12

They can reproduce sexually or asexually. The type depends on the circumstances.

Question 13

What are some advantages to reproducing sexually?

Answer 13

New combination of genes as to avoid predators and the diversity helps adjust to environment.

Question 14

What are some advantages to reproducing asexually?

Answer 14

If population is low, they do not need to find a partner.

Question 15

What is the Red Queen Hypothesis in terms of Biology?

Answer 15

Organisms must always change and adapt in order to stay ahead of predators and disease.

Question 16

Why are protists important?

Answer 16

They produce 50% of the world’s O2, they are the base of many food chains, they help filter water, but some are symbiotic and some are diseases like malaria.

Question 17

How do protists move?

Answer 17

Most protists can move, using structures like pseudopodia (small temporary extensions of body) flagella (String-like structure), cilia (many small hair-like structures), and gliding on protein or carbohydrate-like slime.