Reproduction

Question 1

describe the structure of DNA ?

Answer 1

The DNA molecule consists of two strands that wind around one another to form a shape known as a double helix.

Question 2

What is DNA ?`

Answer 2

DNA is the chemical that all of the genetic material in a cell is made up from

Question 3

Where is DNA found ?

Answer 3

DNA is found in the nucleus of animal and plant cells

Its found in really long structures called chromosomes

Question 4

What is a genome ?

Answer 4

A genome is the genetic material in an organism.

Question 5

What is a gene ?

Answer 5

A small section of DNA found on a chromosome

Each gene codes for a particular sequence of amino acids

Amino acids join together to make protein

Question 6

What is genotype ?

Answer 6

An organisms genetic information

Question 7

What is phenotype ?

Answer 7

Observable physical traits

Question 8

What is heterozygous ?

Answer 8

One dominant and one recessive allele

e.g. Bb

Question 9

What is Homozygous ?

Answer 9

2 of the same allele

e.g. BB or bb

Question 10

What is homozygous dominant ?

Answer 10

2 dominant alleles

e.g. BB

Question 11

What is homozygous recessive ?

Answer 11

2 recessive alleles

e.g. bb

Question 12

What is allele ?

Answer 12

An allele is a variant form of a gene

Question 13

How many chromosomes are in each human body cell ?

Answer 13

23 chromosomes

Question 14

What does 22 chromosome determine ?

Answer 14

They determine your characteristics

Question 15

What does chromosome 23rd pair determine ?

Answer 15

If you are male or female

Question 16

What chromosomes do males have ?

Answer 16

They have one X and Y chromosome

The Y chromosome causes male characteristics

Question 17

What chromosomes do females have ?

Answer 17

They have 2 X chromosomes

The XX allows female characteristics to develop

Question 18

What chromosome does sperm have and what does the egg have ?

Answer 18

Sperm has either X or Y chromosome

All egg cells have an X chromosome

Question 19

What is cystic fibrosis ?

Answer 19

An inherited disorder of cell membrane

Its caused by a recessive allele

Question 20

What is cystic fibrosis controlled by ?

Answer 20

It is controlled by a single gene which has 2 alleles

Question 21

What is a carrier ?

Answer 21

Someone who has 1 cystic fibrosis allele and 1 normal allele which means they don’t have cystic fibrosis

Question 22

How can a child get cystic fibrosis ?

Answer 22

Both parent must be carriers or have the disorder themselves

Question 23

What is the inherited disorder polydactyly ?

Answer 23

People with polydactyly have extra fingers or toes

Question 24

What is polydactyly caused by ?

Answer 24

It is caused by a dominant allele this means that a person with 1 polydactyly and 1 normal allele will have polydactyly

You can’t be a carrier of polydactyly

Question 25

How can polydactyly be inherited ?

Answer 25

It can be inherited if just 1 parent carries a faulty allele

Question 26

What is embryo screening ?

Answer 26

Embryo screening is carried out to test whether embryos have any problems with their chromosomes

Question 27

Arguments against embryo screening

Answer 27

It is too expensive

Some healthy embryos are destroyed people think it is unethical

It suggest people with genetic problems are not wanted - could lead to them being treated unfairly

Question 28

Arguments for embryonic

Answer 28

Helps stop people suffering

There are laws to stop it going too far