3.2 - Chromosomes

Question 1

Describe the sructure and function of nuceloid DNA

Answer 1

Most prokaryotes have one chromosome, consisting of a circular DNA molecule which contains all genes needed for the basic life processes of the cell.

Question 2

Define the term “naked” in relation to prokaryotic DNA

Answer 2

DNA in bacteria, that is not associated with proteins, is described as naked.

Question 3

Describe eukaryotic chromosomes

Answer 3

Linear DNA molecules associated with histone proteins

Question 4

Describe the structure and function of plasmid DNA

Answer 4

S: Small extra DNA molecules
S: Small, circular and naked

F: Contain a few genes that may be useful to the cell - EX: Genes for antibiotic resistance are often located in plasmids.

Question 5

Define diploid and haploid

Answer 5

D - has 2 chromosomes of each - 46.

H - has 1 chromosome of each - 23.

Question 6

Define homologous chromosome

What features do they share?

Answer 6

Chromosomes that carry the same sequence of genes.

Same structural features - size, banding patterns, centromere position.
Same genes at the same loci positions.

Question 7

Describe the process of creating a karyogram

Answer 7

Harvest the cells usually from the foetus or WBC’s of an adult.

Chemically inducing cell division where chromosomes are then condensed.

Chromosomes then stained and photographed.

Question 8

What is a karyotype?

Answer 8

Karyotes are the number and types of chromosomes in a eukaryotic cell