MEIOSIS

Question 1

• reduces # of chromosomes in gametes
• results in sperm and egg cells
• haploid gametes in diploid organisms

Answer 1

Meiosis

Question 2

1 set of chromosomes

Answer 2

Haploid

Question 3

2 sets of chromosomes

Answer 3

Diploid

Question 4

How many phases of meiosis are there?

Answer 4

8

Question 5

• sperm enters with diploid chromosomes and tetraploid DNA
• chromosomes duplicated to produce sister chromatids / homologous dyads

Answer 5

Interphase / Diploid Cell

Question 6

most complex stage of meiosis (90%)

Answer 6

Prophase I

Question 7

dyad pairs align to create tetrads

Answer 7

Prophase I

Question 8

structure containing 4 chromatids

Answer 8

tetrad

Question 9

stage of Meiosis I where synapsis occurs

Answer 9

Prophase I

Question 10

Synapsis is mediated by __________.

Answer 10

synaptonemal complex

Question 11

homologous chromosomes come together as pairs

Answer 11

synapsis

Question 12

stage of Meiosis I where crossing over occurs

Answer 12

Prophase I

Question 13

non-sister chromatids connect and trade sections at a chiasma

Answer 13

crossing over

Question 14

• chromosomes condense
• tetrads move towards center

Answer 14

crossing over

Question 15

• x-shaped structure
• point of contact

Answer 15

chiasma

Question 16

Substages of Prophase I (5)

Answer 16

1. Leptotene
2. Zygotene / Zygonema
3. Pachytene / Pachynema
4. Diplotene
5. Diakinesis

Question 17

substage of Prophase I wherein synapsis occurs

Answer 17

Zygotene / Zygonema

Question 18

substage of Prophase I wherein chromosomes condense and become visible

Answer 18

Leptotene

Question 19

substage of Prophase I
- chromosomes crossover
- chromosomes become shorter and thicker

Answer 19

Pachytene / Pachynema

Question 20

substage of Prophase I
- paired chromosomes begin to separate into 2 chromosome pairs

Answer 20

Diplotene

Question 21

substage of Prophase I
- nuclear membrane disintegrates
- chromatids are more condensed

Answer 21

Diakinesis

Question 22

spindle fibers attach to each dyad at the kinetochore

Answer 22

Metaphase I

Question 23

divides genetic material

Answer 23

spindle fibers

Question 24

pulls sister chromatids apart

Answer 24

kinetochore

Question 25

- chiasmata break apart - migration towards opposite poles

Answer 25

Anaphase I

Question 26

- chromosomes arrive at poles of cell - cleavage furrow forms - begins cytokinesis

Answer 26

Telophase I

Question 27

- spindle fiber disintegrates - results in 2 non-identical haploid (1n) daughter cells

Answer 27

Telophase I

Question 28

Telophase I results in _ non-identical _____ daughter cells

Answer 28

2, haploid

Question 29

division of parental cell into 2 daughter cells

Answer 29

cytokinesis

Question 30

- starts with 2 cells and chromosomes - spindle formation - nuclear envelope breaks down - dyads contract

Answer 30

Prophase II

Question 31

- chromosomes align on metaphase plate - centromeres are directed and divided

Answer 31

Metaphase I / Metaphase II

Question 32

- sister chromatids separate - begin moving towards poles

Answer 32

Anaphase 1 / Anaphase II

Question 33

- cleavage furrow forms beginning cytokinesis - formation of 4 genetically different haploid (1n) cells

Answer 33

Telophase II

Question 34

Telophase II forms _ genetically different _____ cells

Answer 34

4, haploid

Question 35

Stages of Meiosis

Answer 35

1. Prophase 2. Metaphase 3. Anaphase 4. Telophase

Question 36

uncoiled stringy DNA

Answer 36

chromatin

Question 37

each cell has __ pieces of chromatin

Answer 37

46

Question 38

- haploid (1n) - egg and sperm cells - single set of chromosomes for a total of 23 - sex cells

Answer 38

gametes

Question 39

- diploid (2n) - muscle cells, neurons, liver cells - 23 sets of 2 chromosomes for a total of 46 - body cells

Answer 39

somatic cells

Question 40

Meiosis requires _ nuclear division

Answer 40

2

Question 41

In meiosis, chromosomes _____ and _____

Answer 41

synapse, cross over

Question 42

In meiosis, centromeres survive _____

Answer 42

Anaphase I

Question 43

Meiosis _____ chromosome number

Answer 43

halves

Question 44

Meiosis produces _ daughter nuclei

Answer 44

4

Question 45

Meiosis results in daughter cells __________ from parent and each other

Answer 45

genetically different

Question 46

Meiosis is used only for __________ reproduction

Answer 46

sexual

Question 47

_____ meiotic division halves number of chromosomes

Answer 47

First

Question 48

_____ meiotic division preserves number of chromosomes

Answer 48

Second