Genes Y8

Question 1

What does variation mean?

Answer 1

Differences between organisms

Question 2

Organisms of the same species do they have less or more variation than organisms from different species?

Answer 2

They have less variation because they’re the same species

Question 3

What does species mean?

Answer 3

A group of living organisms containing similar individuals

Question 4

What two things can cause variation?

Answer 4

Environment and genes(or both)

Question 5

What type of variation causes eyecolour?

Answer 5

Genes

Question 6

Example of genetic variation

Answer 6

Eyecolour or finger length

Question 7

Example of environmental variation

Answer 7

Tattoos or piercings

Question 8

Example of environmental and genetic variation

Answer 8

Hair colour and skin colour

Question 9

What is continuous variation?

Answer 9

When all the values could follow on from one another Eg height, weight

Question 10

What is discontinuous variation?

Answer 10

The values are in discrete categories e.g eye colour, species of tree

Question 11

Another word for discontinuous

Answer 11

Discreet

Question 12

Are plants more or less likely than animals to be influenced by their environment?

Answer 12

More likely because they cannot move

Question 13

Name some factors in the environment which could affect plant growth

Answer 13

Water, sunlight, minerals (in soil), space, temperature

Question 14

Put these inside order: chromosome, gene, cell, nucleus, DNA molecule (largest to smallest)

Answer 14

Cell, nucleus, chromosome, gene , DNA molecule

Question 15

Where are chromosomes found?

Answer 15

In the nucleus

Question 16

What are chromosomes made of?

Answer 16

DNA

Question 17

What is a gene?

Answer 17

A short section of DNA

Question 18

What is each gene used to make?

Answer 18

Each gene is a code used to make a particular protein in the body

Question 19

How many pairs of chromosomes are there in our bodies?

Answer 19

23(46 chromosomes)

Question 20

What is special about 23rd chromosome pair?

Answer 20

They may not be identical to each other

Question 21

What’s different about sex cells with chromosomes?

Answer 21

They don’t have all 46 chromosomes they only have 23 so one of each pair

Question 22

How does the body decide which chromosomes will be in the sex cells?

Answer 22

It doesn’t it’s random

Question 23

What sex does XY make?

Answer 23

A male

Question 24

What sex does XX make?

Answer 24

Female

Question 25

What does the 23rd pair of chromosomes determine?

Answer 25

Your sex(xx for female, xy for male)

Question 26

Why are twins the best people to study if you want to find out about the how the environment influences characteristics?

Answer 26

you know that any variation has to be caused by their environment, not genetics

Question 27

What is an allele?

Answer 27

Different versions of the same gene

Question 28

How is an allele for eyes different to a gene?

Answer 28

There is a gene that codes for human eye colour, and there are several alleles e.g coding for blue eyes, brown eyes ect

Question 29

How many alleles do you inherit for each gene?

Answer 29

2of each gene

Question 30

What is a dominant allele?

Answer 30

One that is always expressed, ie if even if only one parent gave the allele to the child, it will still be seen

Question 31

Example of a dominant allele

Answer 31

Brown eyes

Question 32

What are recessive alleles?

Answer 32

These can only be expressed when we inherit to one from each of our parents

Question 33

Example of a recessive allele

Answer 33

Blue eyes

Question 34

What is a polygenic traits?

Answer 34

A trait that is controlled by several genes

Question 35

What is a monogenic trait?

Answer 35

A trait that is controlled by one gene