Genetics

Question 1

Pure breeding

Answer 1

Same homozygous so can get only outcomes of the breed they want

Question 2

DNA

Answer 2

Long molecule that contains the genetic code/info in the sequence of their base

Question 3

Gene

Answer 3

A particular protein which determine a characteristic

Question 4

Allele

Answer 4

An alternative form of gene. Different base sequence

Question 5

Mitosis

Answer 5

Produces 2 identical daughter cells used for growth and repair

Question 6

What is the chromosome of a female?

Answer 6

XX

Question 7

What is the chromosome for a male?

Answer 7

XY

Question 8

What is a punnet square?

Answer 8

Gives probabilities of the outcomes

Question 9

How many chromosomes do humans have

Answer 9

46 chromosomes and 23 pairs

Question 10

Inheritance of sex

Answer 10

Each fertilisation has equal chance of producing boy or girl. Male are XY chromosomes and female are XX. Previous offspring to not affect chance

Question 11

Gametes have how many chromosomes

Answer 11

Half the number than normal called haploid.

Question 12

Gamer gas half no. Of chromosomes because?

Answer 12

As when a speed fuses with an egg the resulting zygote has the correct number of chromosomes

Question 13

Ferrilisation

Answer 13

Is random which male gamete fertilises the female gamete- resulting in new combinations of alleles

Question 14

Sexual reproduction

Answer 14

Produces variation between individuals due to random assortment of chromosomes in meiosis and random fertilisation.

Question 15

Advantage of variation to a specie

Answer 15

Some individuals may survive if some change to environment/ threatening events could occur. If a new disease arrives, not all individuals will be wiped out. Individuals best suited to an environment will survive to reproduce and pass on their genes to future generations

Question 16

Mutation

Answer 16

A change in base sequence of a gene/ change in genetic code and therefore a new protein characteristic/ trait being made. Mutations result in new alleles being created within a population( crossing over and independent assortment in meiosis cause a mixing of existing alleles

Question 17

Mutation in gamete

Answer 17

A mutation occurring in a gamete won’t affect the individual but can be passed on/ inherited. The offspring have this mutation in every cell and it can be passed on in their gametes. Mutations in a somatic cells e.g. Skin cell can not be inherited

Question 18

Sexual vs asexual reproduction

Answer 18

Sexual reproduction uses meiosis offspring genetically different- takes longer tine - needs 2parents- but offspring have better disease survival. Asexual uses mitosis all offspring are the same produce identical offspring in large numbers much more quickly but offspring have lack of disease survival