CELL CYCLE AND CELL DIVISION

Question 1

What 3 phases make up interphase

Answer 1

G1
2
G2

Question 2

What 4 happens in G1 phase

Answer 2

Organelle replication
Growth in cell size
Protein synthesis
Respiration

Question 3

What happens at S phase

Answer 3

DNA replication

Question 4

What happens at G2 phase

Answer 4

Organelles replicate
Protein synthesis
Respiration
Cell size increase

Question 5

Describe the 4 things that happen in prophase

Answer 5

• DNA supercoil and condenses
• Nuclear envelope disintegrates
• Centrioles divide and move to opposite poles
• Spindle apparatus is formed from spindle fibres and centrioles

Question 6

Describe the 2 things that happen in metaphase

Answer 6

• Spindle fibres attach onto centromeres of chromosomes
• Chromosomes are pulled to the equator to the cell and line up

Question 7

What 2 things happen during anaphase

Answer 7

• centromeres split
• chromtids move to seperate poles now called chromosomes

Question 8

What happens at telophase

Answer 8

Nucleus reappears and chromosomes become invisible

Question 9

Difference between plant and animal centrioles

Answer 9

Plants don’t have them
Animals use them in mitosis

Question 10

Difference between plant and animal cytokinesis

Answer 10

Plant - cell plate forms from inside
Animal - membrane folds inside

Question 11

Difference between plant and animal spindle fibres

Answer 11

Animal - disintegrates in telophase
Plant - stays for cell wall formation

Question 12

Define crossing over in meiosis

Answer 12

Exchange dna between chromatids on homologous chromosomes in Prophase1

Question 13

What does crossing over allow

Answer 13

Exchange in alleles, variation

Question 14

Define independent assortment

Answer 14

Chromosome are randomly organised on either side of the equator