Chapter 14: How Eukaryotic Cells Sort and Transmit Chromosomes (PART 1)

Question 1

Define cell division.

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Answer 1

it is the reproduction of cells, and is a highly regulated process that distributes and monitors the integrity of the genetic material

Question 2

T or F: Mitosis is needed for sexual reproduction.

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Answer 2

false; MEIOSIS is needed for sexual reproduction

Question 3

Define the cell cycle.

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Answer 3

the series of phases a eukaryotic cell progresses through from its origin until it divides

Question 4

There are 5 stages in the cell cycle. Describe them all briefly.
Draw the cycle, if you dare! :)

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Answer 4

Question 5

What does a karyotype reveal about chromosomes found in actively dividing cells?

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Answer 5

size, number, and centromere position

Question 6

How are eukaryotic chromosomes prepared for cell division?

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Answer 6

the chromosomes are replicated and compacted into sister chromatids

Question 7

What are sister chromatids?

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Answer 7

two identical copies of a chromosome connected by a centromere

Question 8

Does cell divison occur before or after DNA replication?

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Answer 8

after

Question 9

T or F: Each set of chromosomes is composed of the same type.

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Answer 9

false; each set is composed of several different types of chromosomes

Question 10

How many sets of chromosomes are in eukryotic species?

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Answer 10

2; each set has 23 different types of chromosomes; total is 46

Question 11

The chromosomes that are not sex chromosomes are called what? How many do humans have?

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Answer 11

autosomes; 22

Question 12

What is the term that defines organisms whose cells carry two sets of chromosomes?

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Answer 12

a diploid

Question 13

Most human cells are diploid. What is the exception?

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Answer 13

gametes, the sperm and egg cells; they are HAPLOID, which means they only contain one set of chromosomes

Question 14

In humans, which chromosomes determine the sex of the individual?

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Answer 14

X and Y chromosomes
(XX for females; XY for males)

Question 15

What is a homolog?

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Answer 15

a member of a pair of chromosomes in a diploid organisms

Question 16

T or F: The DNA sequences on homologous chromosomes are not similar. In most cases the sequences of bases on one homolog differs by more than 99% from the other sequence on the other homolog.

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Answer 16

false; the DNA sequences on homolongous chromosomes are very similar, and the sequences usually differ by LESS than 1%.

Question 17

Are the X and Y chromosomes homologous? Why, or why not?

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Answer 17

they are not homologous because they are different in size and genetic composition

Question 18

The G1, S and G2 phase are collectively known as what?

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Answer 18

interphase

Question 19

What happens during interphase?

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Answer 19

the cell grows and copies its chromosomes in preparation for cell division; OR cells may exit the cell cycle and remain for long periods of time in a phase called G0 (G zero).

Question 20

What occurs in the G0 (G zero) phase?

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Answer 20

a cell in this phase has postponed division, OR, in the case of terminally differentiated cells (muscle cells in adult animal), will never divide again. NONDIVIDING PHASE!

Question 21

The M phase includes what two processes?

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Answer 21

mitosis and cytokinesis

Question 22

In a cell’s life, cell growth occurs primarily during what phase?

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Answer 22

G1 phase

Question 23

During which phase of the cell cycle are the chromosomes replicated?

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Answer 23

S phase

Question 24

Which phase is the longest phase of the cell cycle, and which is the shortest?

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Answer 24

G1 phase is the longest and the M phase is the shortest.

Question 25

There are two parts of the M phase; define each one. ## Footnote 14.1

Answer 25

**Mitosis**: one cell nucleus divides into two nuclei, each of which receives the same complement of chromosomes **Cytokinesis**: the division of the cytoplasm to produce two distinct daughter cells

Question 26

Which proteins are responsible for advancing a cell through the phases of the cell cycle? ## Footnote 14.1

Answer 26

cyclins and cyclin-dependent kinases

Question 27

T or F: Cyclin dependent kinases do not depend on cyclin to advance the cell cycle. ## Footnote 14.1

Answer 27

false; they do

Question 28

The three critical regulatory points that occur in the cell cycle of eukaryotic cells are called? ## Footnote 14.1

Answer 28

checkpoints

Question 29

What is the aim of a checkpoint protein? ## Footnote 14.1

Answer 29

to prevent the divison of a cell that has incurred DNA damage or harbors abnormalities in chromosome number

Question 30

What factors determine whether or not a cell will divide? ## Footnote 14.1

Answer 30

External: environmental conditions & signaling molecules Internal: cell cycle control molecules & checkpoints

Question 31

Loss of checkpoints can lead to what? ## Footnote 14.1

Answer 31

mutations and cancer

Question 32

What are the products of DNA replication called? | *HINT: THEY ARE THE SAME AS THE PARENT STRAND AND ARE SEMICONSERVATIVE* ## Footnote 14.1

Answer 32

sister chromatids

Question 33

Chromosomes carry what? ## Footnote 14.1

Answer 33

specific information content that holds all of the information of that species (many chromosomes in eukaryotic organisms)

Question 34

One set of human chromosomes contains how many types of different chromosomes? ## Footnote 14.1

Answer 34

23 (1 set) 2 sets (1 from each parent)

Question 35

What does *n* represent in diploid and haploid sets? ## Footnote 14.1

Answer 35

a set of chromosomes (differs from each species)

Question 36

Are homologous chromosomes identical? ## Footnote 14.1

Answer 36

No; they are nearly identical (example: brown eye vs blue eye genes on chromosome 15)

Question 37

Draw the checkpoints and how the cyclin and cyclin dependent kinases advance a cell through the cell cycle.

Answer 37

Question 38

Can both haploid and diploid cells go through the process of mitosis? ## Footnote 14.1

Answer 38

yes

Question 39

Through what process are our cells being duplicated and what process allows for our cells to heal and regenerate? ## Footnote 14.1

Answer 39

mitosis

Question 40

What serve as the microtubule organizing centers? ## Footnote 14.1

Answer 40

centrosomes

Question 41

Draw the different types of microtubules and where they are located in the cell. ## Footnote 14.1

Answer 41

Question 42

Draw and describe the difference between a cleavage furrow and a cell plate in the process of mitosis. ## Footnote 14.1

Answer 42