DNA + RNA

Question 1

DNA structure

Answer 1

• double stranded, antiparallel, a helix
• Read and replicated 5’ to 3’
• Have sugar phosphate backbone (2-deoxyribose)
• A + T, C + G
• associated with proteins - histones

Question 2

DNA replications

Answer 2

Cell cycle
- G1, S, G2, M
- DNA synthesis occurs during S phase

Mitosis
- 1 diploid parent cell produces 2 identical diploid daughter cells

Meiosis
- 1 diploid parent cell produces 4 haploid daughter cells
- gamete formation
- differentiation - crossing over

Question 3

Translation and Translocation

Answer 3

1. Pre-mRNA transcribed from DNA
2. Pre-mRNA spliced into mRNA by having introns removed
   
   • only exon remains
3. mRNA translated into protein in ribosome
   
   • codon ( 3 bases ) codes for amino acid or stop codon
4. Protein is modified and transported around the cell

Question 4

Variation in human genome

Answer 4

Single nucleotide polymorphisms ( SNPs )
- single nucleotide within the sequence is affected
- affect gene function and can make you prone to diseases
- most have no effect

Copy number variations ( CVNs )
- extra or missing stretches of DNA in the sequence caused by insertions or deletions

Question 5

RNA structure

Answer 5

Single stranded
- contains local sections of intramolecular base pairing forming stem-loops

Ribose sugar backbone
- OH group on second carbon

Uracil replaces Thymine

Question 6

3 types of RNA

Answer 6

Ribosomal
- makes up smaller subunit of ribosome
- combines with proteins

Transfer
- carries amino acids to ribosome
- has specific anticodon for each
- each amino acid attaches to OH group on 3’ end
- flatten to form clover leaf structure

Messenger
- carry’s DNA code from nucleus to ribosome in cytoplasm