molecular genetics

Question 1

significance of DNA organisation

Answer 1

1. package large amt of heriditary materials in a small molecule
2. strengthen the DNA structure, for translocation during meiosis/mitosis
3. to minimise the DNA damage
4. control level of gene expression

Question 2

what is one nucleosome?

Answer 2

one histone (8 subunit protein) + DNA wrapped around the histone

Question 3

chromatid definition

Answer 3

the duplicated copy of a chromosome, usually joined with another chromatid at the centromere

Question 4

definition of a gene

Answer 4

• small segment of dna
• specific set of nucleotides
• codes for the synthesis one 1 polypeptide

Question 5

what is a nucleotide made out of?

Answer 5

• 1 phosphate group (joined at the 5’ atom)
• pentose sugar
• nitrogenous base

Question 6

struture of dna

Answer 6

• dounle stranded molecule consisting of 2 polynucleotide chains wound arounf each other foring a double helix
• sugar phosphate backbone with nitrogenous bases projected at rights angles
• adjacent nucletides are held by phosphodiester linkages
• nitrogenous bases from opposite strands are held by hydrogen bonds
• the 2 chains are antiparallel
• complementary base pairing

Question 7

significance of complementary base pairing

Answer 7

1. structure of DNA has to allow for its own replication: the other strand serves as a template for a complementary set of nucleotides to attach by base pairing and hydrogen bonding
2. facilliatte DNA repair: use template strand for a complementary set of nucleptides to attach, giude the repair , base sequence of maintained
3. stability: phosphodiester linkages and hydrogen bonds with hydrophobic interactions

Question 8

types of rna

Answer 8

1. messenger rna
2. transfer rna
3. ribonucleic rna

Question 9

compare dna and rna

Answer 9

• single stranded, double stranded
• pentose sugar is deoxyribose, ribose
• nitrogenous bases: C,G,A,T vs C,G,A,U
• location: mitochondria, chloroplast, nucleus vs cytoplasm and nucleus
• stability: permanent and stable vs temporary and unstable
• type: one type vs many types

Question 10

what is the process of the central dogma?

Answer 10

TRANSCRIPTION: genetic info from DNA is copied to mRNA, and relayed to the cytoplasm. complementary nucleotides attach itself to the template strand base sequence will be equivalent to the coding strand
TRANSLATION: (cytoplasm) genetic information is read by the the ribosome to synthesise and polypeptide

Question 11

why is genetic engineering of insulin needed? why is the current method not practical?

Answer 11

• animal insulin protein is extracted and purified but not identical to human insulin protein
• transmission fo allergens/diseases

Question 12

process of genetic engineering of insulin

Question 13

why is there a need for golden rice?

Answer 13

• it is a transgenic plant that has beta carotene genes.
• in the philliphines, many peopla have vitamin a deficiency, causing blindness
• white rice in their staple food but they are low in vitamin a
  therefore, need to increase the amount of vitamin a

Question 14

benefits of golden rice

Answer 14

• cheap for those in the philliphines as rice is their staple food, cheap source of vitamin a
• reduce the chances of blindness
• new research allows the golden rice not to cause allergies

Question 15

ethical concerns of golden rice

Answer 15

• rise of new GMO, more widespread, hold risk which is not understood
• earlier strains of golden rice had low levels of vitamin a (resolved)
• of the transgenic plant (golden rice) contains genes from animal cells then vegetarians cannot eat it