Mitosis and Meiosis

Question 1

what does diploid mean?

Answer 1

containing two copies of each chromosomes

Question 2

in animals, are autosomal cells diploid or haploid?

Answer 2

diploid (2n)

Question 3

what does haploid mean?

Answer 3

containing only one copy of each chromosomes

Question 4

are germ cells haploid or diploid?

Answer 4

haploid

Question 5

how many chromosomes do humans have?

Answer 5

46 (23 from each parent)

Question 6

what is the cell cycle?

Answer 6

a specific series of phases during which a eukaryotic cell grows, synthesizes DNA, and divides

Question 7

how many stages are in the cell cycle?

Answer 7

four stages

Question 8

what are the stages of the cell cycle?

Answer 8

G1, S, G2, M

Question 9

which stages are in the interphase?

Answer 9

the first three stages of the cell cycle (G1, S, G2)

Question 10

what is the longest part of the cell cycle?

Answer 10

interphase

Question 11

which type of cells does G0 phase have?

Answer 11

cells that do not divide

Question 12

what do cells do in the G0 phase?

Answer 12

simply lives and carries out its functions, without any preparation for division

Question 13

what happens during the G1 phase (presynthetic gap)?

Answer 13

cells create organelles for energy and protein production (mitochondria, ribosomes, ER) while also increasing their size

Question 14

what must the cell pass in order to get from G1 to S phase?

Answer 14

the restriction point

Question 15

what is the restriction point?

Answer 15

certain criteria, such as containing the proper complement of DNA, that the cell must meet to go from G1 to S phase

Question 16

what happens during the S phase (synthesis of DNA)?

Answer 16

• the cell replicates its genetic material so that each daughter cell will have identical copies
• after replication, each each chromosome contains two identical chromatids that are bound together at the centromere

Question 17

what happens in the G2 phase (postsynthetic gap)?

Answer 17

• the cell passes through another quality control checkpoint
• DNA has already been duplicated

Question 18

what happens during the M phase (mitosis)?

Answer 18

• consists of mitosis itself with cytokineses
• divided into four phases: prophase, metaphase, anaphase, telophase

Question 19

what is cytokineses?

Answer 19

the splitting of the cytoplasm and organelles between the two daughter cells

Question 20

what is prophase?

Answer 20

the first stage of mitosis

Question 21

what happens in prophase?

Answer 21

• condensation of chromatin into chromosomes
• centriole pairs move to opposite poles of the cell
• centrioles form spindle fibers (made of microtubules)
• nuclear membrane dissolves

Question 22

what happens in metaphase?

Answer 22

• centriole pairs are now at opposite ends of the cell
• kinetochore fibers interact with spindle fibers to align the chromosomes at metaphase plate (equatorial plate)

Question 23

what happens during anaphase?

Answer 23

• centromeres split so that each chromatid has its own distinct centromere
• sister chromatids are pulled apart towards the opposite poles of the cell

Question 24

what happens during telophase?

Answer 24

• the reverse of prophase
• spindle apparatus disappears
• nuclear membrane reforms around each set of chromatids

Question 25

what is cytokineses?

Answer 25

- occurs at the end of telophase - separation of cytoplasm and organelles, giving each daughter cell enough material to survive on its own

Question 26

what are somatic cells?

Answer 26

cells that do not produce sexually

Question 27

what kind of cells does mitosis occur in?

Answer 27

somatic cells

Question 28

what does mitosis result in?

Answer 28

two identical daughter cells

Question 29

what kind of cells does meiosis occur in?

Answer 29

gametocytes (germ cells)

Question 30

what does meiosis result in?

Answer 30

up to four non identical sex cells (gametes)

Question 31

what are the similarities between mitosis and meiosis?

Answer 31

- genetically material must be duplicated - chromatin is condensed to form chromosomes - microtubules, emanating from centrioles, divide the genetic material

Question 32

how many rounds of replication and division does mitosis have?

Answer 32

one round of replication and one round of division

Question 33

how many rounds of replication and division does meiosis have?

Answer 33

one round of replication and two rounds of division

Question 34

what does meiosis I result in?

Answer 34

results in homologous chromosomes being separated, generating haploid daughter cells

Question 35

what does meiosis II result in?

Answer 35

results in the separation of sister chromatids, without a change in ploidy

Question 36

what is the synapsis in prophase I in meiosis?

Answer 36

when the homologous chromosomes come together and intertwine