2.1 Processes of Cell Replication

Question 1

What is Mitosis

Answer 1

Cell division resulting in two identical daughter cells, with the same number and kind of chromosomes as the parent cell

Question 2

Interphase

Answer 2

Cell prepares itself for division and DNA replication occurs to produce two copies of each chromosome

Question 3

Prophase

Answer 3

Duplicated chromosomes condense
Mitotic spindle form at either end of the cell. Spindles are composed of micro-tubules which lengthen and shorten to pull chromatids apart

Question 4

Metaphase

Answer 4

Pairs of condensed chromosomes (called sister-chromosomes) line up along the equator of the cell

Question 5

Anaphase

Answer 5

• sister chromatids are drawn to opposite poles of the dividing cell by mitotic spindle
• Microtubules bind to chromatids
• Now only one copy of each chromosomes is at each end of the cell

Question 6

Telophase

Answer 6

Two new nuclear envelopes begin to form around the separated sister chromatids

Question 7

Cytokinesis

Answer 7

Two daughter cells are separated by the tightening of a ring of proteins around the middle of the dividing parent cell.
Two Nuclei are squeezed apart

Question 8

Meiosis

Answer 8

cell division resulting in four daughter cells (gametes), each with half the number of chromosomes of the parent cell

Question 9

DNA replication process step 1

Answer 9

Initiation (unzipping)
enzyme helices unwinds and separates complementary DNA strands by breaking the hydrogen bonds between nitrogen bases

Question 10

DNA replication process step 2

Answer 10

Elongation
small pieces of RNA called primers bind to the ends of the strands, signalling the starting point of replication. DNA polymerase binds to seperated DNA strands at primer sites, and begins to add new base pairs which are complementary to the strand.

Question 11

What direction is DNA replicated

Answer 11

5’ to 3’ direction as DNA is antiparallel

Question 12

DNA replication process step 3

Answer 12

Termination
DNA polymerase reaches the end of the DNA molecule and two identical daughter strands have now been produced. Strands recoil into double helix shape, creating two new DNA molecules