molecular genetics

Question 1

parts of dna

Answer 1

deoxyribose sugar
organic nitrogenous base (ATCG)
phosphate group

Question 2

structure of dna

Answer 2

double helix

2 nucleotide polymer strands running in anti parallel directions

Question 3

func of dna

Answer 3

hereditary material responsible for passing genetic info from cell-to-cell or gen-to-gen

Question 4

structure of dna: specific sequence of bases

Answer 4

info in the form of codes to synthesise proteins

Question 5

structure of dna: long

Answer 5

stores more info

Question 6

structure of dna: double helix

Answer 6

provide stability

Question 7

structure of dna: base pairs held by h bonds

Answer 7

easy unzipping for replication of info

Question 8

def genes

Answer 8

segment of dna

contains info to make specific polypeptides

Question 9

triplet code

Answer 9

3 nucleotides in a gene form a codon, each codon codes for 1 amino acid

Question 10

def mutation

Answer 10

a sudden random change in the structure of a gene/in the chromosome number or structure

Question 11

albinism

Answer 11

partial/complete loss of pigmentation of skin, eyes, hair

affects production of melanin

Question 12

down’s syndrome

Answer 12

47 chromosomes instead of 46

genetic condition that causes lifelong mental retardation, developmental delays

Question 13

sickle cell anemia

Answer 13

alters the message by gene that produces haemoglobin, producing haemoglobin s
rbcs have abnormal rigid sickle shape
less efficient in carrying oxygen, tend to get stuck tgt, blocking smaller capillaries, reducing rate of blood flow

Question 14

dna replication

Answer 14

semi conservative

2 dna molecules from 1 original dna molecule

Question 15

rna vs dna

Answer 15

single vs double
5 carbon sugar (ribose) vs deoxyribose
AUCG vs ATCG

Question 16

trna

Answer 16

carries aa to ribosomes, arranges them along mrna where they are linked by peptide bonds to form proteins
specific for aa it binds

Question 17

mrna

Answer 17

single stranded
transfers genetic info necessary for protein synthesis from dna in nucleus to ribosomes in cytoplasm
synthesised in nucleus
bases arranged in triplets which direct formation of proteins by ribosomes

Question 18

rrna

Answer 18

proteins imported from cytoplasm assembled w rrna into large + small ribosomal subunits

Question 19

location: dna replication vs transcription vs translation

Answer 19

nucleus nucleus cytoplasm

Question 20

template: dna replication vs transcription vs translation

Answer 20

dna dna mrna

Question 21

product: dna replication vs transcription vs translation

Answer 21

dna mrna polypeptide

Question 22

def genetic engineering

Answer 22

manipulation of organism’s genetic material
involves transfer of genes from 1 organism to another
result: transgenic animal/plant
involves use of vector molecule eg plasmids

Question 23

def plasmids

Answer 23

circular
double stranded dna
separate from chromosomal dna
capable of replicating independently from chromosomal dna

Question 24

def sticky ends

Answer 24

single stranded sequence of dna bases found on cut end of gene
bases can pair w complementary bases to form double strand
hold 2 pieces of dna together so they can be sealed by dna ligase

Question 25

def restriction enzyme

Answer 25

protein that recognises a specific short nucleotide sequence + cuts dna only at specific site

Question 26

insulin prod

Answer 26

1. isolate gene using restriction enzyme, prod sticky ends
2. cut bacterial plasmid using same enzyme, prod complementary sticky ends
3. mix
4. dna ligase seal gene to cut plasmid via complementary base pairing, prod recombinant plasmid
5. mix recombinant plasmid w bacteria
6. temp heat/electric shock to open pores in cell surface membrane of bacterium for plasmid to enter
7. bacteria mass cultured in fermenters. insulin extracted + purified

Question 27

genetic engineering: env

Answer 27

+ crops resistance to drought, frost, pest, disease, herbicides
+ GE oil consuming bacteria released into wild to clean up oil spills on sea + land
- loss of biodiversity: GM plants produce toxins kills insects
- herbicide resistant plants cross-bred w weeds
- insects develop resistance to toxins from GM crops

Question 28

genetic engineering: econ

Answer 28

+ livestock GE give max output at min cost for farmer
+ herbicide/pesticide resistance crops incur cost savings for farmers
- prices of seeds not regulated, poorer farmers don’t have financial capacity to benefit from tech while rich farmers continue to get richer

Question 29

genetic engineering: health

Answer 29

+ treatment of diseases (cystic fibrosis)
+ prod of new organs, overcome organ shortage for transplant
+ food designed to meet specific nutritional goals
- antibiotic resistant genes accidentally incorperated into disease-causing bact
- intro of allergens into food, ppl unknowingly consume transgenic food containing protein they’re allergic to
- chem/bio warfare
- accidental prod of harmful toxins in food crops