C3: Meiosis

Question 1

describe prophase 1 in meiosis 1

Answer 1

similar to mitosis with the addition of:
homologous chromosomes pair up to form a tetrad so they can cross over with each other (this is called synapsis)

Question 2

describe what synapsis is

Answer 2

when homologous chromosomes pair up (forming a tetrad) and generate new combinations of alleles instead of only parental combinations

Question 3

describe metaphase 1 in meiosis 1

Answer 3

different from mitosis!!
homologous chromosomes pair up on either side of the metaphase plate

Question 4

describe anaphase 1 in meiosis 1

Answer 4

different from mitosis,
homologous chromosomes are moved to either side of the cell, chromatids do not separate, cells stay diploid

Question 5

describe telophase 1 in meiosis 1

Answer 5

one chromosome in each cell that are haploid

Question 6

describe prophase 2 in meiosis 2

Answer 6

same as mitosis

Question 7

describe metaphase 2 in meiosis 2

Answer 7

same as mitosis but the cell is haploid

Question 8

describe anaphase 2 in meiosis 2

Answer 8

same as mitosis but the cell goes from haploid to diploid as the sister chromatids separate and go to opposite sides of the cell

Question 9

describe telophase 2 in meiosis 2

Answer 9

cleavage furrow made of microfilaments undoes prophase, there are 4 haploid cells at the end

Question 10

what is the purpose of mitosis vs. meiosis (respectively)?

Answer 10

• replication
• reproduction

Question 11

what are the products of mitosis vs. meiosis (respectively)?

Answer 11

• somatic cells
• gametes (eggs and sperm)

Question 12

what is the # of cell divisions of mitosis vs. meiosis (respectively)?

Answer 12

• 1
• 2

Question 13

what is the # of daughter cells of mitosis vs. meiosis (respectively)?

Answer 13

• 2
• 4

Question 14

what is the daughter ploidy of mitosis vs. meiosis (respectively)?

Answer 14

• diploid
• haploid

Question 15

what is the G1 of mitosis vs. meiosis (respectively)?

Answer 15

• 2n1x
• 2n1x

Question 16

what is the S (DNA replication) of mitosis vs. meiosis (respectively)?

Answer 16

• 2n1x to 2n2x
• 2n1x to 2n2x

Question 17

what is the G2 of mitosis vs. meiosis (respectively)?

Answer 17

• 2n2x
• 2n2x

Question 18

what is the anaphase 1 of mitosis vs. meiosis (respectively)?

Answer 18

• 2n2x to 4n1x
• 2n2x to 2n2x

Question 19

what is the end of telophase 1 of mitosis vs. meiosis (respectively)?

Answer 19

• 2n1x
• 1n2x

Question 20

what is the anaphase 2 of mitosis vs. meiosis (respectively)?

Answer 20

• n/a
• 1n2x to 2n1x

Question 21

what is the end of telophase 2 of mitosis vs. meiosis (respectively)?

Answer 21

• n/a
• 1n1x

Question 22

what is nondisjunction?

Answer 22

chromosome separation gone wrong

Question 23

• what is trisomy?
• monosomy?

Answer 23

• a zygote w 3 copies of a chromosome
• a zygote w 1 copy of a chromosome

Question 24

what are the 2 types on nondisjunction?

Answer 24

• anaphase 1 failure
• anaphase 2 failure

Question 25

describe anaphase 1 failure

Answer 25

starts w homologous chromosomes in the cell (like normal) but error occurs where once the cell divides only 1 of them gets both chromosomes and the other cell gets none. after this if normal meiosis 2 occurs, (the product being 4 cells) 2 of the cells end up w 2 chromatids each and the other 2 cells dont end up w anything (all 4 cells are abnormal)

Question 26

describe anaphase 2 failure

Answer 26

starts w homologous chromosomes in the cell (like normal), goes through normal meiosis 1 (1 chromosome in each cell), and then error occurs where there is still a product of cells BUT 2 of them are normal (1 chromatid in each), 1 of them has a chromosome, and the other has nothing (first 2 cells are fine, other 2 are abnormal)