Genetic Info, Variation And Relationships Between Organaism Section Four

Question 1

What is the proteome of a cell

Answer 1

The full range of different proteins that a cell is able to produce at a given time

Or

The full range of different proteins the genome/DNA is able to code for

Question 2

Give two structural differences between an mRNA and tRNA molecule (2)

Answer 2

• mRNA does not have hydrogen bonds/base pairing. tRNA does
• mRNA is a linear/straight chain, tRNA is a cloverleaf shape
• mRNA does not have an amino acid binding site, tRNA does
• mRNA has more nucleotides
• mRNA has codons, tRNA has anticodons

Question 3

Ways in which dna in chloroplast is different from dna in the nucleus

Answer 3

In chloroplasts-
- dna is shorter
- fewer genera
- dna is circular not linear
- not associated with proteins/histones, unlike nuclear DNA
- introns absent but present in nuclear DNA

Question 4

A difference between the structure of a DNA nucleotide and the structure of an RNA nucleotide

Answer 4

DNA has deoxyribose, rna has ribose

Question 5

Why are not all mutations in the nucleotide sequence of a gene causing change in the structure of a polypeptide

Answer 5

• triplets code for the same amino acid
• occurs in introns/non coding sequence

Question 6

Starting with mRNA, describe how translation lead to the production of a polypeptide.
Do not include descriptions of transcription and splicing in your answer

Answer 6

1) A ribosome attaches to mRNA
2) the ribosome

Question 7

Define universal (genetic code)

Answer 7

The same codon/triplet always codes for the same amino acid

Question 8

Define non overlapping (genetic code)

Answer 8

Each base is only part of one triplet/codon

Question 9

Define degenerate code

Answer 9

More than one codon/triplet codes for each amino acid

Question 10

What is a homologous pair of chromosomes?

Answer 10

Two chromosomes that carry the same genes

Question 11

Two ways in which the arrangement of prokaryotic dna is different from the arrangement of human DNA

Answer 11

Prokaryotic dna is
- circular instead of linear
- not associated with proteins/histones

Question 12

What is species richness

Answer 12

A measure of the number of different species in a community

Question 13

What is degenerate genetic code?

Answer 13

More than one codon codes for a single amino acid.