#1 | Meiosis Model

Question 1

Cell Cycle

Answer 1

G1 | Growth and checkpoints for cell damage
S | Synthesis; DNA replication
G2 | Growth and checkpoints for cell damage
M | Cell division; Meiosis occurs`

Question 2

What is Meiosis?

Answer 2

• Type of cell division producing 4 unique haploid daughter cells
• Half genetic information from mother and father, 23 chromosomes
• Produce gametes from germ cells; eggs and sperm

Question 3

Interphase | 1/2

Answer 3

• First cycle of Meiosis
• Chromatin; un-condensed indistinct chromosomes
• Nuclear envelope
• Plasma membrane
• G1, S, G2

Question 4

Interphase | 2/2

Answer 4

• Genetically identical chromosomes
• DNA replication

Question 5

Prophase 1 | 1/2

Answer 5

• Spindle fibres form; composed of microtubules from centrosomes
• 2n
• Chromatins condense into visible chromosomes
• Homologous chromosomes pair

Question 6

Prophase 1 | 2/2

Answer 6

• Crossing over occurs
• Bivalents formed with homologous chromosomes held together by DNA cross over
• Exchange of DNA; genetic variation of mother and father alleles being swapped

Question 7

Metaphase 1

Answer 7

• Homologous chromosomes line up on metaphase plate
• Spindle fibres attach to centromeres
• Independent assortment | Random orientation of homologous chromosome pairs; genetic diversity increases with random chance of genes being passed on

Question 8

Anaphase 1

Answer 8

• Spindle fibres shorten; pull by centromeres
• Homologous pairs separate to opposite poles of the cell

Question 9

Telophase 1

Answer 9

• Nuclear envelope forms around separated chromosomes
• New nuclei form each side; two new cells
• Cleavage furrow forms
• Spindle fibres break down

Question 10

Cytokinesis

Answer 10

• Cell divides into 2 non-identical daughter cells
• Diploid | 46 chromosomes

Question 11

Interkinesis

Answer 11

• Second cycle of Meiosis occurs
• Chromosomes de-condense into into chromatin form; indistinct
• No DNA replication occurs

Question 12

Prophase 2

Answer 12

• Spindle fibres form
• Nuclear envelope breaks down
• Chromatins condense into visible chromosomes

Question 13

Metaphase 2

Answer 13

• Spindle fibres attach at centromeres
• Chromosomes line up single file on metaphase plate

Question 14

Anaphase 2

Answer 14

• Spindle fibres shorten
• Sister chromatids separate to opposite ends of cell
• Random segregation occurs | random separation of chromatids to opposite poles of cell; parental genes have random and equal chance passing onto offspring

Question 15

Telophase 2

Answer 15

• Cleavage furrow forms
• Nuclear envelope surrounds chromatids
• Spindle fibres break down

Question 16

Cytokinesis

Answer 16

• Gametes produced
• 4 haploid daughter cells; 23 chromosomes
• Contain half amount of parent genetic material

Question 17

Results of Meiosis

Answer 17

• Ensure species continuity
• Allow for sexual reproduction with produced gametes
• New allele combination for genetic diversity, organisms can adapt to environmental changes

Question 18

What are tetrads?

Answer 18

• Contains 2 homologous chromosomes with 4 sister chromatids
• In Prophase 1 | 1/2

Question 19

What is Independent Assortment?

Answer 19

• Random orientation of homologous chromosome pairs; genetic diversity increases with random chance of genes being passed on
• Metaphase 1

Question 20

Difference between diploid and haploid?

Answer 20

• Diploid | 46 chromosomes
• Haploid | 23 chromosomes; half genetic information from both parents

Question 21

What is Random Segregation?

Answer 21

• Random separation of chromatids to opposite poles of cell; parental genes have random and equal chance passing onto offspring
• Anaphase 2