Christmas Mock HW Flashcards
1
Q
Describe how DNA is replicated.
A
- DNA helicase separates the 2 strands
- by breaking the hydrogen bonds between the 2 strands
- each strand acts as a template
- free-floating nucleotides are attracted to the exposed bases
- by complimentary base-pairing
- DNA polymerase joins the free-nucleotide on the new strand
- the hydrogen bonds reforms
- semi-conservative
- new DNA molecules contain one old strand and one new strand
2
Q
Explain how the doctor could have recognised which cells were in interphase when looking at the samples.
A
there would have been no visible chromosomes/no visible nucleus
3
Q
Which tissue sample was taken from a cancerous tumour?
A
- lower percentage of cells in interphase
- higher percentage of cells in mitosis
- so more cells dividing
- more cells dividing quicker
4
Q
Name one organelle you would expect to find in large numbers in a mucus-secreting cell. Describe its role in the production of mucus.
A
Ribosomes RER mitochondria Golgi Vesicle
5
Q
Complete the table to give 2 differences between the structure of DNA and the structure of RNA
A
DNA double stranded nitrogenous base thymine very long deoxyribose sugar RNA single stranded nitrogenous base uracil shorter ribose sugar
