Biology 5 9A Genetics and evolution

Question 1

Give an adaptation of an egg cell

Answer 1

It’s jelly coat only allows a single sperm cell to enter.

Question 2

Give an adaptation of a sperm cell

Answer 2

Has a long tail to make it travel faster or has a streamlined shape

Question 3

Name one recessive allel

Answer 3

Blue eyes, green eyes, blonde hair, or ginger hair

Question 4

Explain the purpose of a punnett square

Answer 4

To find the probability of a certain characteristic getting passed on to the off-spring

Question 5

Name an example of an environment characteristic

Answer 5

Skin colour (tan), length of hair, or accents

Question 6

Define genetic information

Answer 6

The instructions, carried by the genes, that control you characteristics

Question 7

Define characteristics

Answer 7

The features of an organism

Question 8

Explain the role of a male gamete

Answer 8

To fuse two of the nuclei and fertilise the egg cell

Question 9

Define cell division

Answer 9

When a cell grows in size and splits into two. Cells increase their numbers using cell division.

Question 10

What is formed when a fertilised egg goes through cell division?

Answer 10

It forms an embryo

Question 11

What is the difference between inherited and environmental characteristics?

Answer 11

The inherited characteristics are passed on from parents and the environment controls the environmental characteristics.

Question 12

What would be the probability for a child of a parent with blue eyes and a parent with brown eyes and a recessive allel for blue eyes, be to get blue eyes?

Answer 12

50% for blue eyes

Question 13

Define genotype and phenotype

Answer 13

Genotype: The genes that determine what the phenotype of an organism will be. Phenotype: The physical characteristics of an organism

Question 14

Why does a person have brown eyes if they also carry an allel for blue eyes?

Answer 14

Because brown eyes are a dominant allel so the blue eyes will not have an effect as they are a recessive allel.

Question 15

Define homozygous and heterozygous

Answer 15

Homozygous: When both of the genes are the same type. Heterozygous: When the genes are different from each other.

Question 16

If a person has blue eyes what type of genes would they have? Heterozygous or Homozygous?

Answer 16

Homozygous because blue eyes are a recessive allel and show only when the genes are both the same.

Question 17

Give the four steps of Selective Breeding

Answer 17

Firstly, the characteristics which are important are decided. Then the parents that show these characteristics are chosen. Next the best off-spring from the parents are selected to breed with the next generation. Finally the process is continuously repeated.

Question 18

Define natural selection

Answer 18

A process founded by Charles Darwin which states that over a long period of time when species evolved, the fittest survive while the weakest eventually died off.

Question 19

What are some desirable characteristics in animals?

Answer 19

Gentle, produce a lot of food, immune to certain diseases, etc.

Question 20

Describe the process of cloning mammals.

Answer 20

The nucleus of an egg cell is fused with a cell of the mammal getting cloned and then cell division happens forming an embryo. The embryo is then implanted into the mammal that the nucleus came from.

Question 21

Give an argument for and against genetic modifications.

Answer 21

There is too little information about the long-term effects of altering DNA(Against). It offers the prospect of cures for currently incurable disease(For). Etc.

Question 22

Name some enviormental factors that might effect characteristics.

Answer 22

The climate of the environment, the proteins and vitamins that can be provided in that environment, the people in that environment, etc.