DNA and Meiosis

Question 1

What happens during metaphase I?

Answer 1

Homologous chromosomes line up in PAIRS in the middle of the cell.

Question 2

What is a haploid cell? What is the haploid number in humans? Give an example.

Answer 2

• A haploid cell is a cell with one set of chromosomes
• 23
• Sperm and egg

Question 3

What is the biggest difference between spermatogenesis and oogenesis?

Answer 3

In spermatogenesis 4 haploid cells form; only 1 mature egg forms in oogenesis (cytoplasm is unequally divided)

Question 4

What is spermatogenesis? How many haploid cells form?

Answer 4

-Sperm production in males
-4 haploids from one diploid

Question 5

What is a monomer of DNA?

Answer 5

A nucleotide

Question 6

What is a monosomy?

Answer 6

The loss of a chromosome as a result of nondisjunction

Question 7

What stage is this?

Answer 7

Anaphase II

Question 8

What stage is this?

Answer 8

Metaphase II

Question 9

What is the female karyotype?

Answer 9

XX

Question 10

What stage is this?

Answer 10

Telophase II

Question 11

What are the nitrogenous bases?
(Write out spelling)

Answer 11

1. Adenine
2. Thymine
3. Guanine
4. Cytosine

Question 12

What happens during prophase I?
(Hint: 4 things)

Answer 12

• Homologous chromosomes condense
• Crossing over occurs
• Nuclear membrane breaks down
• Spindle fibres attach

Question 13

What stage is this?

Answer 13

Telophase I

Question 14

What happens during anaphase II?

Answer 14

-Chromosomes split at the centromere
-Sister chromatids move to opposite ends of the cell

Question 15

What do the order of nitrogenous bases determine?

Answer 15

Genectic sequence/DNA sequence

Question 16

What stage is this?

Answer 16

Prophase I

Question 17

What are purines? What are they?

Answer 17

• Two ringed bases
• Adenine and Guanine

Question 18

What happens during telophase II?

Answer 18

-Nuclei form around chromatids
-Spindle fibres break down

Question 19

What happens during crossing over?

Answer 19

Exchange of segments of chromosomes that occur between a pair of homologous chromosomes.

Question 20

What is a tetrad? What is an autosome?

Answer 20

• A pair of homologous chromosomes
• A NON-SEX chromome

Question 21

What are the two outcomes of meiosis?
Describe them.

Answer 21

Genetic reduction: Produces daughter cells with half the number of chromosomes of parents cells. (End product: 4 daughter cells)
Genetic Recombination: Products of meiosis have different combinations of alleles.

Question 22

What are pyrimidines? What are they?

Answer 22

• One ringed bases
• Thymine and Cytosine

Question 23

What are the remaining 3 haploid cells in oogenesis called? What is their function?

Answer 23

-Polar bodies
-Help with fertilization

Question 24

What is the male karyotype?

Answer 24

XY

Question 25

What stage is this?

Answer 25

Metaphase I

Question 26

What is a trisomy?

Answer 26

Gain of an extra chromosome as a result of nondisjunction

Question 27

What are the 4 errors in structure during meiosis? Describe them.

Answer 27

Deletion: A piece of a chromosome is deleted Duplication: A section of a chromosome appears two or more times Inversion: A section of a chromosome becomes inverted (ATTAG - GATTA) Translocation: A large section of a chromosome attaches to another

Question 28

What is the structure of DNA?

Answer 28

1. Double Helix Shape 2. Pentose Sugar and phosphate (sides of the ladder) 3. Nitrogenous bases link with hydrogen bonds (steps of the ladder)

Question 29

What stage is this?

Answer 29

Prophase II

Question 30

What happens during anaphase I?

Answer 30

Homologous chromosomes are separated and pulled to opposite sides of the cell.

Question 31

What happens during telophase I? (Hint: 3 things)

Answer 31

-Spindle fibres break down -Nuclear membrane begins to form around two nuclei -Cytokinesis occurs and the cell separates into two daughter cells

Question 32

Define nondisjunction:

Answer 32

The failure of homologous chromosome pairs or sister chromatids to separate during meiosis

Question 33

What is a diploid cell? What is a diploid number in humans? Give an example.

Answer 33

- A diploid cell is a cell with two sets of chromosomes - 46 - Body cells

Question 34

What stage is this?

Answer 34

Anaphase I

Question 35

What happens during metaphase II?

Answer 35

Individual chromosomes line up in the middle of the cell

Question 36

What is oogenesis? How many haploid cells form?

Answer 36

-Egg production in females -1 MATURE EGG forms from one diploid

Question 37

What do nucleotide consist of?

Answer 37

1. A phosphate group 2. 5 carbon sugar 3. Nitrogenous bases

Question 38

What is Chargaff's rule?

Answer 38

Adenine binds with thymine (A+T) Guanine binds with cytosine (G + C)

Question 39

What happens during prophase II?

Answer 39

Chromatin tighten and spindle fibres attach to chromosomes

Question 40

What is a homologous chromosome? Give an example.

Answer 40

One pair of chromosomes that share similar characteristics; one from each parent. (Example: Similar length, similar centromere location, same genes in same spots)

Question 41

Compare and contrast mitosis vs meiosis

Answer 41

Answer on paper