Protein Synthesis

Question 1

What is an exon a sequence of?

Answer 1

Base sequence coding for polypeptide

Question 2

What does mRNA not have that tRNA does?

Answer 2

Hydrogen bonds / base pairing

Question 3

What is the shape of mRNA compared to tRNA?

Answer 3

mRNA is linear / straight chain, tRNA is cloverleaf

Question 4

What does tRNA have that mRNA doesn’t?

Answer 4

Amino acid binding site

Question 5

Which type of RNA has more nucleotides?

Answer 5

mRNA

Question 6

Do different mRNAs or tRNAs have different lengths?

Answer 6

Different mRNAs have different lengths, all tRNAs are similar / same length

Question 7

What does mRNA have that tRNA doesn’t?

Answer 7

Codons

Question 8

What does tRNA have that mRNA doesn’t?

Answer 8

Anticodon

Question 9

What is an allele?

Answer 9

(Different) form/type/version of a gene / different base sequence of a gene

Question 10

What is a gene a sequence of?

Answer 10

DNA (nucleotide) bases

Question 11

What does a gene code for?

Answer 11

A polypeptide / functional RNA / rRNA / tRNAs / sequence of amino acids / primary structure

Question 12

What causes variation in a population?

Answer 12

Mutation

Question 13

What selects for different features in selection?

Answer 13

Environmental/abiotic/biotic conditions / selection pressures

Question 14

What gets selected during natural selection?

Answer 14

Advantageous features/characteristics/mutation/allele

Question 15

What happens to the allele frequency during selection?

Answer 15

It changes

Question 16

Over what time frame does natural selection occur?

Answer 16

A long period of time

Question 17

What is the genetic code described as if multiple codons code for the same amino acid?

Answer 17

Degenerate

Question 18

What does non-overlapping DNA mean?

Answer 18

A base from one triplet cannot be used in an adjacent triplet

Question 19

What breaks during transcription?

Answer 19

Hydrogen bonds (between DNA bases)

Question 20

How many DNA strands act as a template in transcription?

Answer 20

One

Question 21

What aligns with DNA during transcription?

Answer 21

(Free) RNA nucleotides

Question 22

What base in RNA pairs with adenine in DNA?

Answer 22

Uracil

Question 23

What joins RNA nucleotides together during transcription?

Answer 23

RNA polymerase

Question 24

What type of bonds are formed between RNA nucleotides?

Answer 24

Phosphodiester bonds

Question 25

What is removed from pre-mRNA during splicing?

Answer 25

Introns

Question 26

Where does mRNA attach during translation?

Answer 26

Ribosomes / rough endoplasmic reticulum

Question 27

What binds to complementary codons on mRNA?

Answer 27

tRNA anticodons

Question 28

What does tRNA bring to the ribosome?

Answer 28

A specific amino acid

Question 29

What joins amino acids together?

Answer 29

Peptide bonds

Question 30

What is used to form peptide bonds?

Answer 30

ATP

Question 31

What happens to tRNA after it delivers its amino acid?

Answer 31

It is released

Question 32

What moves along the mRNA during translation?

Answer 32

The ribosome

Question 33

What does ATP do during translation?

Answer 33

Releases energy

Question 34

What does ATP allow to happen in translation?

Answer 34

Peptide bonds form OR Amino acid joins to tRNA

Question 35

What can a mutation in a gene coding for an enzyme change first?

Answer 35

Base sequence (of DNA/gene)

Question 36

What does a change in DNA base sequence lead to?

Answer 36

Change in amino acid sequence / primary structure (of enzyme)

Question 37

What does a change in primary structure affect?

Answer 37

Hydrogen/ionic/disulphide bonds

Question 38

What structural level is altered by bonding changes?

Answer 38

Tertiary structure / active site

Question 39

Why is a mutated enzyme non-functional?

Answer 39

Substrate not complementary / cannot bind / no enzyme-substrate complexes form

Question 40

Why might a gene mutation cause no change in a polypeptide?

Answer 40

Triplets code for same amino acid OR mutation in introns / non-coding sequence

Question 41

What is a gene mutation?

Answer 41

Change in the base/nucleotide sequence of chromosomes/DNA

Question 42

What can a gene mutation result in?

Answer 42

Formation of new allele

Question 43

Why might a mutation have no effect?

Answer 43

Degenerate code OR in an intron OR no change in tertiary structure OR allele is recessive

Question 44

How can a mutation have a positive effect?

Answer 44

Change in polypeptide positively changes properties of protein

Question 45

What might this lead to?

Answer 45

Increased reproductive success or survival