(s4-8) DNA, Genes & Protein Synthesis

Question 1

Genes & Genetic Code

How is DNA organised into chromosomes?

Answer 1

DNA is wrapped around histones to form a DNA-histone complex, which then coils further to form a chromosomes.

Question 2

Genes & Genetic Code

What are the differences between eukaryotic and prokaryotic DNA?

Answer 2

1. Eukaryotic DNA is stored in the nucleus, prokaryotic DNA is stored in the cytoplasm.
2. Eukaryotic DNA is longer than prokaryotic DNA.
3. Eukaryotic DNA is linear, prokaryotic DNA is circular.
4. Eukaryotic DNA is associated with histones, prokaryotic DNA is not.
5. Eukaryotic DNA contains introns, prokaryotic DNA does not.

Question 3

Genes & Genetic Code

Other than the nucleus, which eukaryotic organelles contain DNA?

Answer 3

Mitochondria and chloroplasts also contain DNA.

Question 4

Genes & Genetic Code

Describe the structure of DNA inside mitochondria and chloroplasts.

Answer 4

DNA inside mitochondria and chloroplasts is short, circular, and not associated with histones.

Question 5

Genes & Genetic Code

What is a gene?

Answer 5

A gene is a short section of DNA that codes for a polypetide.

Question 6

Genes & Genetic Code

What is the difference between introns and exons?

Answer 6

Introns are non-coding regions that do not code for amino acids, whereas exons are coding regions that do code for amino acids.

Question 7

Genes & Genetic Code

What is a locus?

Answer 7

A locus is a specific position along a chromosome where a gene is located.

Question 8

Genes & Genetic Code

What is the difference between a genome and a proteome?

Answer 8

A genome is the** complete set of genes** within a cell, where a proteome is the full range of proteins that a cell is capable of producing.

Question 9

Genes & Genetic Code

What is the genetic code?

Answer 9

The genetic code is the sequence of bases that code for amino acids.

Question 10

Genes & Genetic Code

What is a triplet?

Answer 10

A triplet is a sequence of 3 DNA bases that code for a single amino acid.

Question 11

Genes & Genetic Code

What is the genetic code universal?

Answer 11

The genetic code is universal because each DNA triplet codes for the same amino acid in all organisms (with a few exceptions)

Question 12

Genes & Genetic Code

What is the genetic code described as being non-overlapping?

Answer 12

The genetic code is described as being non-overlapping because each base in the DNA sequence is only read once.

Question 13

Genes & Genetic Code

Why is the genetic code degenerate?

Answer 13

The genetic code is degenerate because most amino acids are coded for by more than one triplet.