Inheritance

Question 1

What is DNA?

Answer 1

DNA is the molecule that contains the instructions for growth and development of all organisms

Question 2

What is the genome?

Answer 2

The genome is the entire set of DNA instructions found in a cell.

Question 4

What does a genome contain?

Answer 4

A genome contains all the information needed for an individual to develop and function.

Question 5

What is a gene?

Answer 5

A length of DNA on a chromosome that codes for a specific protein.

Question 6

Where are chromosomes located?

Answer 6

The nucleus of a cell.

Question 7

What is mutation?

Answer 7

mutation is a rare, random change in genetic material that can be inherited.

Question 8

What causes genetic variation in offspring?

Answer 8

Random fertilisation.

Question 9

Why does random fertilisation occur?

Answer 9

Because there are no two egg or sperm cells that are identical so no two siblings can be identical.

Question 10

What is a diploid?

Answer 10

A cell containing two complete sets of chromosomes, one from each parent.

Question 11

Diploid number in human cells?

Answer 11

46

Question 12

What is a haploid cell?

Answer 12

Haploid refers to the presence of a single set of chromosomes in an organism’s cells.
In humans, only the egg and sperm cells are haploid.

Question 13

What number of chromosomes are there in a haploid cell?

Answer 13

23

Question 14

What are the causes of variation in species?

Answer 14

Genetic, environmental or both.

Question 15

What is an allele?

Answer 15

An allele is a version of a gene.

Question 16

What is a dominant allele?

Answer 16

A dominant allele is an allele that is expressed in the phenotype in both homozygotes and heterozygotes
The capital letter in the genotypes.

Question 18

What is a recessive allele?

Answer 18

An allele that is only expressed in the phenotype of homozygotes.
The lower case letter.

Question 19

What does homozygous mean?

Answer 19

A genotype where both alleles for a gene are the same.

Question 20

What does heterozygous mean?

Answer 20

A genotype where the alleles for a gene are different.

Question 21

What is a phenotype?

Answer 21

The physical characteristics of an individual.

Question 22

What is a genotype?

Answer 22

The alleles an individual has for a specific gene. E.g EE or Ee

Question 23

What is polygenic inheritance?

Answer 23

Polygenic inheritance refers to traits that are determined by multiple genes.

Question 24

Are most phenotypic features determined by polygenic inheritance or single genes?

Answer 24

Polygenic features.

Question 25

XX chromosomes?

Answer 25

Females

Question 26

XY chromosomes?

Answer 26

Males

Question 27

How can resistance to antibiotics lead to increase in bacterial populations?

Answer 27

A random mutation can cause a new bacterial allele that codes for antibiotic resistance.
When the bacterial population is exposed to an antibiotic, only those with the resistant allele survive.
The surviving bacteria are more likely to reproduce, passing on their alleles to their offspring.
Over several generations the frequency of the resistant allele increases, leading to a antibiotic resistant strain of bacteria.