Inheritance

Question 1

What are two types of variation?

Answer 1

Continuous and discontinuous

Question 2

What is continuous variation?

Answer 2

Can be any value within a range
No distinct categories
Can be shown by a normal distribution - belt curve
E.g. Height, weight

Question 3

What is discontinuous variation?

Answer 3

When there is two or more distinct categories
Each individual falls into only one of these categories
No intermediates
Can be represented as bar chart
E.g. Blood group, eye colour

Question 4

What is phenotype?

Answer 4

The characteristics the genotype displays

Question 5

What are the three factors of phenotype variation?

Answer 5

Genotype
Environment
Both

Question 6

What is alleles?

Answer 6

Different version of genes

Question 7

w

What is a gene?

Answer 7

a sequence of bases on a DNA molecule that codes for a protein which results in a characteristic

Question 8

What is genotype?

Answer 8

the alleles an organism has.

Question 9

What is homozygous alleles?

Answer 9

When it has two copies of the same alleles

Question 10

What is heterozygous alleles?

Answer 10

When it has two different alleles

Question 11

What is codominant alleles?

Answer 11

Some alleles are both expressed in the phenotype because neither one is reccessive

Question 12

What is a carrier?

Answer 12

A person carrying an allele which is not expressed in the phenotype but that can be passed on to offspring

Question 13

What is monogenic inheritance?

Answer 13

the inheritance of a characteristic controlled by a single gene

Question 14

What is the example for codominant monogenic inheritance?

Answer 14

Sickle-cell anaemia

Question 15

What is sex-linked characteristic?

Answer 15

Alleles that code for them are located on a sex chromosome and carry fewer genes

Question 16

What causes X-linked gene

Answer 16

X-chromosomes is larger than Y-chromosomes and carry more genes
This means males have higher chance of inheriting some disease

Question 17

What is autosomal chromosomes?

Answer 17

Any chromosomes that is not sex chromosomes

Question 18

How does autosomal linkage work?

Answer 18

• Genes on the same autosome are said to be linked
• Because they’ll stay together during the independent assortment during meiosis 1
• Their alleles will be passed on to offspring together
• The closer the two genes are on the autosome, the less likely crossing over is going to split them up, so they are also said to be linked

Question 19

What is epistasis?

Answer 19

The allele of one gene masks the expression of the alleles of other genes

Question 20

What is chi-squared test?

Answer 20

to see if the reuslt of an experiment support a theory