Bio Chapter 11

Question 1

Meiosis

Answer 1

Reduces the number of chromosome sets from diploid to haploid
Meiosis takes place in 2 consecutive cell divisions (meiosis I and II)
Results in 4 daughter cells - Each daughter cell has only half as many chromosomes as the parent cell

Question 2

Phases of meiosis I

Answer 2

Prophase I
Metaphase I
Anaphase I
Telophase I and cytokinesis

Question 3

Period between meiosis I and meiosis II
Period before meiosis I and II

Answer 3

Interkinesis
Interphase

Question 4

Phases of meiosis II

Answer 4

Prophase II
Metaphase II
Anaphase II
Telophase II and cytokinesis
Very similar to mitosis

Question 5

Interphase

Answer 5

DNA synthesis and chromosome replication phase

Question 6

Meiosis I

Answer 6

4n to 2n, separate chromosomes

Question 7

Meiosis II

Answer 7

Separate chromatids

Question 8

Prophase I

Answer 8

Mother and father cross over and exchange
Chromosome pairs with its homolog

Question 9

Tetrad

Answer 9

Four sister chromatids of two homologous chromosomes

Question 10

Chiasma/chiasmata

Answer 10

Location where two chromosomes cross

Question 11

Metaphase I

Answer 11

Pairs of homologs line up at the metaphase plate with one chromosome facing each pole
Microtubules from one pole are attached to the kinetochore of one chromosome of each pair
Microtubules from the other pole are attached to the kinetochore of the other chromosome

Question 12

Anaphase I

Answer 12

Pairs of homologous chromosomes separate
One chromosome of each pair moves toward opposite poles guided by the spindle apparatus
Sister chromatids remain attached at the centromere and move as one unit toward the pole

Question 13

Telophase I

Answer 13

Each half of the cell has a haploid set of chromosomes
Each chromosome still consists of 2 sister chromatids

Question 14

Cytokinesis

Answer 14

Usually occurs simultaneously
Forms 2 haploid daughter cells
Animal cells form cleavage furrow
Plant cells form cell plate

Question 15

Interkinesis

Answer 15

Nuclear membrane re-forms around chromosomes, spindle breaks down and chromosomes relax
No chromosome replication

Question 16

Prophase II

Answer 16

Spindle apparatus forms
Chromosomes move toward the metaphase plate

Question 17

Metaphase II

Answer 17

Sister chromatids are arranged at the metaphase plate
Kinetochores of sister chromatids attach to microtubules extending from opposite poles

Question 18

Anaphase II

Answer 18

The sister chromatids separate and move to opposite poles

Question 19

Telophase II

Answer 19

Chromosomes arrive at opposite poles, nuclei form and chromosomes begin de-condensing

Question 20

Cytokinesis in meiosis II

Answer 20

Separates the cytoplasm

Question 21

Egg

Answer 21

XX

Question 22

Sperm

Answer 22

XY

Question 23

Autosomes

Answer 23

Any chromosome that isn’t a sex chromosome

Question 24

Homologous chromosomes

Answer 24

Includes one chromosome from each parent
46 chromosomes in a human somatic cell are 2 sets of 23 (1 from mother and 1 from father)

Question 25

Asexual reproduction vs. sexual

Answer 25

Asexual is a single individual passes all of its genes to its offspring, so it’s genetically identical
Sexual is 2 parents give rise to offspring that have combination of genes from the 2 parents
Sexual is better because it has genetic variation