Biology 30 - Mitosis & Meiosis

Question 1

Why do cells grow?

Answer 1

• Growth
• Maintenance
• Repair

Question 2

Asexual reproduction

Answer 2

• No genetic variation
• Faster

Question 3

Stomatic cells

Answer 3

• All contain homologous pairs
  
  • 23 mother’s eggs
  • 23 fathers sperm
  • 46 in total (23 pairs)
• Not identical
  X - Mother
  Y - Father

Question 4

Karyotype

Answer 4

• Test of genetic material

Question 5

Cell cycle

Answer 5

• Continuous
  
  1. Interphase (G1, S, G2)
  2. Cell division (Mitosis)
  3. Cytokinesis

Question 6

Interphase

Answer 6

• 90% of cell cycle time
• Nucleus is well defined and bound by the nuclear membrane

Question 7

PMAT

Answer 7

P - Prophase
M - Metaphase
A - Anaphase
T - Telophase

Question 8

Prophase (Mitosis)

Answer 8

1. Chromosomes condense
2. Nuclear envelop disappears
3. Centrioles move to opposite poles admitting spindle fibers
4. Nucleolus dissapears
   - 46 sets (92 chromosomes)

Question 9

Metaphase (Mitosis)

Answer 9

• Sets line up in single file along the metaphase plate (Equator)

Question 10

Anaphase (Mitosis)

Answer 10

• Separation of sister chromatids
• 46 chromosomes at each pole

Question 11

Telophase (Mitosis)

Answer 11

• Chromosomes decoil/decondense
• Nuclear envelop forms around each group of 46 chromosomes
• Nucleolus comes back
• At the same time, third stage of cell cycle begins (cytokinesis)

Question 12

Cytokinesis

Answer 12

• Cell starts to pinch in
• The division of the cytoplasm

Question 13

Sexual reproduction

Answer 13

• Genetic variation
• Slower

Question 14

Diploid

Answer 14

• 46 chromosomes
• 23 homologous pairs

Question 15

Gametes

Answer 15

• Sex cells

Question 16

Meiosis

Answer 16

• Formation of gametes
• Occurs only in sex cells
• Involves two cell divisions
  
  1. Meiosis I
  2. Meiosis II
• Leads to four haploid cells

Question 17

What is the name for the first 22 pairs of chromosomes in meiosis?

Answer 17

• Autosomes

Question 18

What is the name for the last pair #23 of chromosomes in meiosis?

Answer 18

• Sex chromosomes

Question 19

Prophrase I (meiosis)

Answer 19

• Admits meiotic spindle fibers instead of spindle fibers
• Exchanging genetic information between non sister chromatids
• Synapsis & crossing over occurs

Question 20

Tetrad

Answer 20

• Two homologous pairs beside each other
• 4 chromosomes

Question 21

Synapsis

Answer 21

• Homologous pairs finding each other

Question 22

Crossing over

Answer 22

• Cause of genetic diversity
• No sister chromatids will now be identical

Question 23

Metaphase I (meiosis)

Answer 23

• Homologous pairs line up opposite of each other instead of single file line

Question 24

Anaphase I (meiosis)

Answer 24

• Homologous pairs get pulled apart to each pole
• Goes from diploids to haploids
• Ends with two non identical sister chromatids

Question 25

Segregation

Answer 25

• Pulling apart of the homologous pairs

Question 26

Meiosis II

Answer 26

• Starts with 23 sets of sister chromatids instead of 46 in mitosis
• Same steps in cell reproduction as mitosis just with non-identical chromosomes and only 23 sets in each of the cells (separation of sister chromatids)

Question 27

Polar body

Answer 27

• Small haploid cell that is formed at the same time as an egg cell

Question 28

Alleles

Answer 28

• One of two or more versions of a genetic sequence at a particular region on a chromosome

Question 29

Gene

Answer 29

• A segment of DNA coding for a specific trait or protein.

Question 30

G1 (Growth 1)

Answer 30

• General growth & organelle replication, protein synthesis
• DNA consists of a single (unreplicated) chromatin molecule (46 strands)

Question 31

S (Synthesis)

Answer 31

• Replication of chromosomal material (DNA)

Question 32

G2 (Growth 2)

Answer 32

• Structures associated with mitosis & cytokinesis are replicated (cell membrane, proteins, centrioles)