Unit Six - Mitosis & Meiosis - Meiosis

Question 1

Definition of Meiosis (3)

Answer 1

1. Produces Gametes
2. Occurs in Gonads
3. Ensures genetic diversity

Question 2

Definition of Gametes (3)

Answer 2

1. Haploid Cell (NO PAIRS)
2. Sex Cells
3. Egg & Sperm

Question 3

Definition of Gonads (3)

Answer 3

1. Reproductive Organs
2. Produce Gametes
3. Ovaries & Testes

Question 4

What is Meiosis made of? (2)

Answer 4

1. Meiosis 1 & Meiosis 2
2. Mitosis needs to occur twice to form 4 nonidentical cells

Question 5

What is the goal of Meiosis 1? (2)

Answer 5

1. Forms Haploid Cells
2. Separate Homologous Chromosomes

Question 6

What is Meiosis 1 made up of?

Answer 6

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

Question 7

What occurs in Interphase 1? (4)

Answer 7

1. Metabolic Activities Proceed
2. Parent Cells Duplicate
3. 1 parent cell undergoes meiosis
4. Other remains in gonads to prevent net loss of parent cells in meiosis

Question 8

What is the parent cell in meiosis? (3)

Answer 8

1. Diploid Cell
2. Undergoes Meiosis
3. To produce non identical haploid cells (gametes)

Question 9

Definition of Synapsis (2)

Answer 9

1. Joining of Homologous Chromosomes
2. Overlap allows a tetrad to form

Question 10

Definition of Crossing Over in Meiosis (4)

Answer 10

1. Swapping of Genetic Material
2. Between Chromosomes
3. To Increase Variation
4. No Genetic Material is Lost

Question 11

What occurs in Prophase 1? (3)

Answer 11

1. Spindle Fibers form
2. Synapsis forms a Tetrad
3. Crossing over occurs between Chromosomes

Question 12

Definition of Tetrad (2)

Answer 12

1. Group of 4 Chromatid
2. Formed by synapsis of chromosomes

Question 13

What occurs in Metaphase 1? (2)

Answer 13

1. Law of Independent Assortment
2. Chromosomes Align at Metaphase Plate

Question 14

Definition of the Law of Independent Assortment (3)

Answer 14

1. Chromosomes randomly align on metaphase plate
2. Allows random distribution of chromosomes to gametes
3. Increasing variation & randomizing maternal/parental chromosomes
   (Each chromosome in homologous chromosomes come from either mother or father)

Question 15

What occurs in Anaphase 1? (2)

Answer 15

1. Disjunction - Separation of Homologous Chromosomes
2. Chromosomes move to opposite poles

Question 16

Definition of Telophase 1 (2)

Answer 16

1. Chromosomes are at the poles
2. Chromosomes decondense

Question 17

Definition of the Law of Segregation (4)

Answer 17

1. Homologous Chromosomes Separate
2. Distributed to diff. daughter cells
3. Reduces chromosome number in 1/2
4. Makes the cell haploid

Question 18

What is the only difference between Meiosis II and Mitosis?

Answer 18

Chromosomes DO NOT REPLICATE in interphase

Question 19

What occurs in interphase II? (2)

Answer 19

1. Does Not Occur
2. Cells temporarily rest

Question 20

What is another way of saying meiosis?

Answer 20

1. Gametogenesis - Formation of Gametes
2. Spermatogenesis (in males)
3. Oogenesis (in females)

Question 20

What happens if the egg is not fertilized?

Answer 20

The egg will not finish meiosis two and shed during menstruation

Question 21

What is variation created by? (4)

Answer 21

1. Crossing Over (Prophase I)
2. Independent Assortment (Metaphase 1)
3. Segregation (Anaphase I)
4. Recombination (Fertilization)

Question 21

What causes mutations?

Answer 21

Mutagenic Agents/Mutagens

Question 21

What causes variation (4)?

Answer 21

1. Crossing Over (Prophase I)
2. Independent Assortment (Metaphase I)
3. Segregation (Anaphase I)
4. Recombination (Fertilization)

Question 22

What are the two occurrences that cause chromosome abnormalities? (2)

Answer 22

1. Nondisjunction 2. Crossing Over Errors

Question 22

What are three types of nondisjunction?

Answer 22

1. Monosomy 2. Trisomy 3. Polyploidy

Question 22

What are three types of crossing over errors?

Answer 22

1. Addition/Deletion 2. Inversion 3. Translocation

Question 22

Definition of Monosomy

Answer 22

1 chromosome in a cell instead of 2 XX -- X__

Question 22

Definition of Nondisjunction

Answer 22

Homologous chromosomes do not separate Ex: One cell has 3 chromosomes and the other only has 1

Question 23

Definition of Trisomy

Answer 23

3 chromosomes in a cell instead of 1 XX -- XXX, XXY, XYY

Question 24

Definition of Polyploidy (3)

Answer 24

1. Common in Plants 2. 2n -- 4n instead of 1n 3. No Disjunction Occurred

Question 25

Definition of Deletion/Addition

Answer 25

Deletion - Missing Genetic Material in Chromosome (CAUSE) Addition - Additional Genetic Material in Chromosome (RESULT)

Question 26

Definition of Inversion

Answer 26

Sequence of genes are reversed

Question 27

Definition of Translocation

Answer 27

Crossover between 2 nonhomologous chromosomes

Question 28

What causes mutations?

Answer 28

Mutagenic Mutations/Mutagens

Question 29

Definition of Recombination (3)

Answer 29

1. Occurs in Fertilization 2. Genetic material exchanged between chromosomes 3. Between Egg & Sperm

Question 30

Definition of Autosome

Answer 30

Body Chromosomes (1 - 22)

Question 31

Definition of Sex Chromosome

Answer 31

Chromosome 23 Female = XX Male = XY

Question 32

What is the difference between the daughter cells of the ovaries and testes?

Answer 32

Ovaries - One Egg and 3 Polar Bodies Testes - 4 Sperm