Cell division

Question 1

what are the two types of nuclear divisions

Answer 1

1. mitosis
2. meiosis

Question 3

define gene

Answer 3

gene is a specific sequence of nucleotides along a DNA molecule that codes for a specific sequence of amino acids that make up a polypeptide chain.

Question 4

where is a gene found

Answer 4

locus (s) - specific location on a chromosome

Question 5

after DNA replication…. what is formed?

Answer 5

2 genetically identical DNA molecules joined at the centromere

when chromotin condenses -> visible DNA molecule = sister chromatid

Question 6

outline how cancer is caused

Question 7

what is the function of tumor suppressor genes?

Answer 7

codes for proteins that inhibit normal cell growth by preventing stimulating activity of cellular proto-oncogenes or oncogenes
e.g :
1. as components in the cell-signalling pathwas that inhibit the cell cycle
2. activate DNA repair proteins that repaur damaged DNA, preventing accumulation of cancer-causing mutations
3. activate proteins that trigger apoptosis of irreparably-damaged cells