B2 - Inheritance and Genes

Question 1

Order these from largest to smallest.
Chromosome
Nucleus
Gene
Cell

Answer 1

Cell > Nucleus > Chromosome > Gene

Question 2

Define nucleus.

Answer 2

The control centre of the cell. Contains the genes in the chromosomes.

Question 3

Define chromosomes.

Answer 3

They are made up of long strings of DNA. They can be found in the nucleus of the cell. A human has 46 in every cell; 23 pairs.

Question 4

Define DNA.

Answer 4

It carries instructions that make up proteins. Proteins then make up a majority of cell structures.

Question 5

Define gene.

Answer 5

Small sections of the DNA which contain a characteristic.

Question 6

Define allele.

Answer 6

All the different forms of the same gene (eg. eye colour - blue eyes, brown eyes, green eyes…)

Question 7

What does homozygous mean?

Answer 7

Two genes the same. Eg BB.

Question 8

What does heterozygous mean?

Answer 8

Two different genes. e.g. Bb.

Question 9

What is a genotype?

Answer 9

The pair of alleles an individual has (the pair of letters eg. bb)

Question 10

What is a phenotype?

Answer 10

The physical characteristic a person has.

Question 11

What are gametes? Name them in males, females and plants.

Answer 11

Sex cells.
MALES - SPERM
FEMALES - EGG
PLANTS - POLLEN.