U1 KA3

Question 1

What does the genome contain?

Answer 1

• all genetic info of a person.

Question 2

What is an organisms genotype?

Answer 2

• a combinations of all genes, (AA, Aa, aa).

Question 3

What is an organisms phenotype?

Answer 3

• the organisms observable traits,
  (brown eyes, blonde hair).

Question 4

What is gene expression, and what does it involve? (2)

Answer 4

• a process in which info from a gene is used for protein synthesis.
• involves transcription and translation.

Question 5

What are the key features of RNA? (4)

Answer 5

• single stranded.
• composed of nucleotides.
• has a uracil base instead of thymine.
• contains a ribose sugar.

Question 6

What is the role of mRNA?

Answer 6

• messenger RNA carries a copy of genetic code from the nucleus to the ribosome.

Question 7

What is the role of tRNA?

Answer 7

• transfer RNA carries an amino acid to the ribosome.
• it has an anti-codon, and an amino acid attachment site.

Question 8

What is a codon made up of?

Answer 8

• three bases put together (mRNA).
• each one codes for an amino acid.

Question 9

What is an anti-codon?

Answer 9

• three bases put together (tRNA).
• each one is complimentary to a specific codon.

Question 10

Where does Transcription occur?

Answer 10

• the Nucleus.

Question 11

What are the stages of Transcription? (3)

Answer 11

• RNA polymerase unwinds the the DNA structure breaking apart the hydrogen bond.
• primary transcript is synthesised as RNA polymerase adds nucleotides to form mRNA.
• primary transcript undergoes RNA Splicing to form the mature transcript.

Question 12

What is RNA Splicing?

Answer 12

• the process by which introns are removed from the primary mRNA transcript.
• the remaining exons are spliced together to form the mature transcript.

Question 13

What is the intron?

Answer 13

• the non-coding region of the primary mRNA transcript.

Question 14

What is the exon?

Answer 14

• the coding region of the primary mRNA transcript.

Question 15

Where does translation occur?

Answer 15

• the ribosome.

Question 16

What are the stages of translation? (6)

Answer 16

• mature mRNA transcript travels in the cytoplasm and attaches to a ribosome.
• tRNA transports amino acids to the ribosome.
• a start codon initiates translation.
• mRNA codons match with tRNA anti-codons.
• peptide bonds form between the amino acids.
• a stop codon terminates translation and a polypeptide is formed.

Question 17

What is alternative RNA splicing?

Answer 17

• it allows multiple mature transcripts to be formed from a single primary transcript by selectively retaining some exons.

Question 18

What does the protein shape determine?

Answer 18

• the function of the protein.

Question 19

What substances make up the ribosome? (3)

Answer 19

• rRNA.
• protein.
• enzymes.

Question 20

How can a polypeptide be modified?

Answer 20

• by adding phosphate.