Chapter 8

Question 1

What is the cell theory? Hint: where do cells come from?

Answer 1

Cells come from other cells.

Question 2

Prokaryotic cells reproduce by B_ _ _ _ y F _ _ _ _ _ _n.

Answer 2

Binary fission.

Question 3

True or false: a prokaryotic cell only has one circular DNA.

Answer 3

True.

Question 4

What is replication?

Answer 4

Making copies of DNA.

Question 5

True or false: there is only 1 chromosome in eukaryotic cells.

Answer 5

False, there can be more than 1.

Question 6

True or false: eukaryotic cells chromosomes are straight linear.

Answer 6

True.

Question 7

Do different species have different numbers of chromosomes in their cells, or do all species have the same number?

Answer 7

Different species have different numbers.

Question 8

True or false: chromosomes and chromatins are NOT both DNA and protein combinations.

Answer 8

False, they both are.

Question 9

Where is eukaryotic genetic material stored?

Answer 9

The nucleus.

Question 10

True or false: before a cell divides, it duplicates all of its chromosomes, resulting in two copies called sister chromatids.

Answer 10

True.

Question 11

True or false: two sister chromatids attach to each other at centromere.

Answer 11

True.

Question 12

The sister chromatids are so sisterly that they never separate from each other, even during cell division.

Answer 12

False, they do separate during cell division.

Question 13

Human somatic cells have _ _ chromosomes?

Answer 13

46.

Question 14

True or false: eukaryotic cell cycle includes interphase and mitotic phase.

Interphase includes G1, S phase and G2, it is during S phase when DNA replication occurs.

Answer 14

Both are true.

Question 15

What is the division of the nucleus called? M _ _ _ _ _ s.

Answer 15

Mitosis is the division of the nucleus.

Question 16

What is the division of cytoplasm called? C _ _ _ _ _ _ _ _ _ s.

Answer 16

Cytokinesis is the division of cytoplasm.

Question 17

True or false: animals and plants go through cytokinesis exactly the same way.

Answer 17

False.

Question 18

What are the 4 basic phases of mitosis?

1) P _ _ _ _ _ _ e
2) M _ _ _ _ _ _ _ e
3) A _ _ _ _ _ _ e
4) T _ _ _ _ _ _ _ e

Answer 18

1) Prophase
2) Metaphase
3) Anaphase
4) telophase

Question 19

What happens during prophase?

• chromosomes first become visible
• nuclear envelope disintegrates
• centrosomes (centrioles in animals) make protein cables/a spindle.
• cables in a spindle are made of microtubules.
• microtubules attach to chromosomes
• Process is complete when the sister chromatids of a duplicated chromosome are attached by 2 microtubules to opposite poles of the cell.

Answer 19

Chromosomes first become visible with a microscope because the nuclear envelope begins to disintegrate. Centrosomes (centrioles in animal cells) begin to assemble a network of protein cables called the spindle. Cables in the spindle are made of microtubules. Microtubules attach to chromosomes. Process is complete when the sister chromatids are attached by 2 microtubules to opposite poles of the cell.

Question 20

What happens during prophase? (simplified version).

Answer 20

Microtubules attach to sister chromatids and bring them to opposite poles of the cell.

Question 21

Why are spindles important? Hint: think of their function. They pull the sister chromatids to opposite poles of the cell.

Answer 21

They are responsible for ensuring that cell division is correct.

Question 22

What happens during metaphase? Hint: the sister chromatids leave the poles and go back to the c _ _ _ _ r.

Answer 22

The sister chromatid pair are aligned in the center of the cell.

Question 23

What happens during anaphase? Hint: the sister chromatids no longer want to live together… again.

Answer 23

Sister Chromatids separate from each other at centromere and move away from each other toward opposite poles of the cell.

Question 24

What happens during telophase? Hint: the spindle gives up on the sisters because of the separating, moving in, and separating again. The sisters can’t set aside their differences this time, so they form a N _ _ _ _ _ r E _ _ _ _ _ _ e around the set of chromosomes at each pole.

Answer 24

The spindle is dismantled. A nuclear envelope forms around the set of chromosomes at each pole. The chromosomes begin to de-condense. The nucleolus reappears.