Lecture 4 - The Cell Cycle and Mitosis

Question 1

Chromosomes

Answer 1

• Double Helix of DNA
• Complexed with Proteins (Histones)
• Several Levels of Coiling and Folding

Question 2

Centromere

Question 3

Sister Chromatids

Answer 3

• Joined at the centromere

Question 4

Interphase

Answer 4

G1 - Cells perform normal functions
S - DNA synthesis and replication, replicated chromosome with 2 chromatids
G2 - Cell growth continues and organelle replicate
- Formation of centrosomes to organise that spindle

Question 5

Interphase (G2)

Answer 5

• Phase where cell growth and DNA replication occur.
• Inter = “between”
• Longest Stage

Question 6

Chromosome duplication

Question 7

Prophase

Answer 7

Setting Up

Condenses and attach to spindle fibres

Question 8

Metaphase

Answer 8

Lining Up

Aligned in a plane across the centre of the cell

Question 9

Anaphase

Answer 9

Splitting Up

Spindles pull the towards opposite poles of the spindle

(cleavage of chromatids is triggered by an enzyme)

Question 10

Telophase

Answer 10

Fixing Up

Dismantle Spindle and build new nuclei

Question 11

Cytoskeleton

Answer 11

Spindle of microtubules

Question 12

Output of mitosis

Answer 12

• Two nuclei identical to that of the starting cell
• Each of these nuclei will form a daughter cell
• The daughter cells are genetically identical

Question 13

Mitochondrial Divison

Answer 13

• When a cell is preparing to divide the existing mitochondria duplicate themselves
• They have their own DNA and replicate independently by fission

Question 14

Cytokinesis

Answer 14

• Divison of cytoplasm and formation of two daughter cells