DNA, RNA and Protein Synthesis- DNA, Genes and Chromosomes

Question 1

What kind of DNA do eukaryotic cells contain?

Answer 1

Linear DNA that exist as chromosomes- each made up of one long molecule of DNA and found in the nucleus

Question 2

How does eukaryotic DNA fit into the nucleus?

Answer 2

It is wound up because it is really long

Question 3

What are the proteins called that eukaryotic DNA are wrapped around?

Answer 3

Histones

Question 4

What is the role of histones?

Answer 4

Help to support the DNA

Question 5

How is eukaryotic DNA different in the mitochondria and chloroplasts to in the nucleus?

Answer 5

Circular and shorter, and not associated with histones

Question 6

How is prokaryotic DNA different to eukaryotic DNA?

Answer 6

Shorter and circular, and it isn’t wound around histones

Question 7

How does prokaryotic DNA condense to fit into the cell?

Answer 7

By supercoiling

Question 8

What is a gene?

Answer 8

A sequence of DNA bases that codes for either a polypeptide or functional RNA

Question 9

What determines the order of amino acids in a particular polypeptide?

Answer 9

The order of bases in a gene

Question 10

What is each amino acid coded for?

Answer 10

A sequence of 3 bases known as a triplet

Question 11

How is a polypeptide made?

Answer 11

DNA is first copied into messenger RNA (mRNA) which is the first stage of protein synthesis

Question 12

What is functional RNA?

Answer 12

RNA molecules other than mRNA which performs special tasks during protein synthesis- tRNA and rNA

Question 13

What are introns?

Answer 13

Sections of eukaryotic DNA that don’t code for amino acids

Question 14

What are exons?

Answer 14

Sections of eukaryotic DNA that do code for amino acids

Question 15

Why are the introns removed during protein synthesis?

Answer 15

So they don’t affect the amino acid order

Question 16

What are the regions of multiple repeats outside of genes that eukaryotic DNA contain?

Answer 16

DNA sequences that repeat over and over, don’t code for amino acids, called non-coding repeats

Question 17

What are alleles?

Answer 17

Different forms of a gene

Question 18

Why do different alleles code for a slightly different version of the same polypeptide?

Answer 18

The order of bases in each allele is slightly different

Question 19

How many chromosomes do humans have?

Answer 19

23 pairs- 46 in total

Question 20

What are homologous pairs?

Answer 20

Pairs of matching chromosomes

Question 21

What are chromosomes like in a homologous pair?

Answer 21

Both are same size and have the same genes although they could have different alleles- alleles coding for the same characteristic will be found at the same locus on each chromosome