DNA, genes and Protein synthesis Ch.8

Question 1

Definition of Gene

Answer 1

A section if DNA on a chromosome coding for one or more polypeptides.

Question 2

Why is the genetic code said to be universal?

Answer 2

All organisms use the same genetic code

Question 3

Locus

Answer 3

The position on a chromosome where a gene is found

Question 4

Universal

Answer 4

All organisms have the same genetic code

Question 5

Genome

Answer 5

All the genes contained within the cell (includes mitochondria and chloroplast)

Question 6

Degenerate

Answer 6

An amino acid may be coded for by more than one codon

Question 7

Redundant

Answer 7

Same as degenerate, when an amino acid may be coded for by more than one codon

Question 8

(Triplet) Codon

Answer 8

Three nucleotides that correspond to a specific amino acid or stop signal

Question 9

Allele

Answer 9

An alternative form of a gene

Question 10

Histone

Answer 10

Protein around what DNA is wrapped around. In this form chromosomes are called chromatin.

Question 11

Homologous

Answer 11

A pair of chromosomes where one is provided by the father and one by the mother.

Question 12

Proteome

Answer 12

All the proteins that are coded for by the genome

Question 13

Intron

Answer 13

Sequence of non-coding DNA

Question 14

Exon

Answer 14

Sequence of coding DNA

Question 15

Chromosome

Answer 15

Strand of DNA encoded with genes

Question 16

Non-overlapping

Answer 16

Each base is only read once in a sequential order.

Question 17

Diploid

Answer 17

A cell containing two sets of chromosomes one from mother and one from father.

Question 18

Prokaryotes DNA structure?

Answer 18

Short, circular and not associated with proteins.

Question 19

Eukaryotes DNA structure?

Answer 19

long, linear and associated with proteins, called histones. Form chromosomes

Question 20

Whats the structure of DNA in the mitochondria and chloroplast?

Answer 20

Like prokaryotes, short, circular and not

associated with protein.

Question 21

What’s the difference between RNA and DNA?

Answer 21

DNA is double stranded, and has Thymine, and has ribose sugar.

Question 22

What’s the structure of mRNA?

Answer 22

A single long stand in a single helix.

Question 23

What’s the structure of tRNA?

Answer 23

Folded single stranded chain, has anticodon.

Question 24

Which has hydrogen bond? DNA, tRNA, mRNA

Answer 24

DNA and tRNA

Question 25

Put in order of most stable to least stable. tRNA, mRNA and DNA

Answer 25

DNA, tRNA then mRNA

Question 26

What is transcription?

Answer 26

Producing mRNA from tRNA

Question 27

How is mRNA made?

Answer 27

• DNA helicase breaks the H bonds b/n bases and the DNA unwinds and unzips.
• One of the two stands act as a template strand.
• Free nucleotide pair with complementary bases on template strand.
• RNA polymerase joins the nucleotides forming pre-mRNA
• Pre-mRNA is spliced and introns are removed.
• mRNA leaves via nuclear pore

Question 28

What happens in splicing?

Answer 28

Introns (non-coding DNA is removed)

Question 29

Does splicing occur in prokaryotes?

Answer 29

No

Question 30

What is translation?

Answer 30

The production of polypeptides from mRNA

Question 31

Explain the process of translation

Answer 31

• Ribosome attaches to the starting codon of the mRNA,
• A tRNA with complimentary anticodon sequence to mRNA moves to ribosomes and pairs with the mRNA.
• The tRNA carries a specific amino acid
• The next tRNA pairs with the next mRNA codon which carries another amino acid.
• Two amino acids form peptide bonds.
• Ribosome moves to third codon and so on.