Genetics&cell Biology

Question 1

Name 4 macromolecules and what they’re made of

Answer 1

Polysaccharides (from sugars)
Fats (fatty acids)
Proteins (amino acids)
Nucleic acids (nucleotides)

Question 2

What is homeostasis

Name 2 ways cell maintains homeostasis

Answer 2

Property of a system to regulate its internal environment to maintain a stable, constant condition
1 balancing cell division w/ apoptosis
2 altruism of infected/damaged cells

Question 3

Name 3 polysaccharides

Answer 3

Maltose- glucose&glucose
Sucrose- fructose&gkucose
Lactose- galactose&glucose

Question 4

Functions of glycoproteins

Answer 4

1 cell recognition
2 prevent cells sticking
3 cell communication

Question 5

How are fats stored

Answer 5

Glycerides

Question 6

Functions of nucleic acids

Answer 6

1 release energy
2 coenzymes
3 cell signalling

Question 7

Describe DNA replication

Answer 7

• unwind at replication origin/forks
• DNA polymerase adds vases from 5’-3’ direction on 3’-5’ template strand to form leading strand
• lagging strand forms from 5’-3’ template strand
• Okazaki fragments joined by DNA ligase
• DNA polymerase proof reads/repairs
• semi-conservative

Question 8

Describe transcription

Answer 8

• RNA polymerase adds based on 3’-5’ template
• spliced to form mRNA
• polyA tail and 5’cap added

Question 9

Describe translation

Answer 9

Ribosome attaches to start codon methionine

• tRNA brings amino acid by complementary anticodon to A site
• peptide bond forms in P site
• old tRNA finds other amino acids
• until stop codon

Question 10

How is gene expression regulated

Answer 10

1 histone acetylation
2 transcription factors bind to promotor region causing RNA polymerase to start transcribing (oestrogen/glucocorticoid)
3 alternative splicing changes properties of protein (VEGFA)
4 miRNAs w/ RISC- miRNA bind to 3’-UTR on mRNA and protein degrades it - used as biomarkers/indicate where cancer originated

Question 11

Describe PCR

Answer 11

• 95 denature
• 55 anneal, excess of primers on opposite strands
• 72 extend by DNA polymerase

Question 12

Uses of Next Generation Seq

Answer 12

1 mutation detection
2pharmacogenetics
3 gene expression
4 microbiology -genome of pathogens

Question 13

How to classify chromosomes

Answer 13

1 size
2 banding pattern
3 centromere position
(Telocentric/acrocentric/submetacebtric/metacentric)

Question 14

Name 2 diseases that occur due to chromatin disorder

Answer 14

1 ATRX syndrome- unwinds chromatin

2 Rett syndrome - chromatin structure due to gene mutation

Question 15

Define aneuploidy and eg

Answer 15

Specific additional/missing chromosome

Eg DS- trisomy 21

Question 16

2 aneuploidy sex conditions

Answer 16

Turners syndrome x

Klinefelter syndrome xxy

Question 17

Heteroplasmy

Answer 17

When balance of mutant and normal DNA in mitochondria is unbalanced so not enough energy can be produced

Question 18

Name the 6 chromosome abnormalities

Answer 18

1 mono/trisomy- extra chromosome 
2 deletion 
3 duplication 
4 inversion 
5 ring 
6 reciprocal translocation - robertsonian translocation= one less chr

Question 19

Ways to obtain chromosomal info

Answer 19

Amniotic fluid, chorionic villus samples, blood, tissue biopsy

Question 20

Name 5 cytogenetic analysis

Answer 20

1 Karyotype
2 Banding- giesma dye makes GC light 
3 painting/FISH (fluorescent in situ hybridisation) DNA probes- chr number/specific sequence 
4 arrays- deletions 
5 whole genome seq