4.6.1 Reproduction (will come up) P2 2

Question 1

What is a mutation

Answer 1

A random change in the base sequence of DNA which results mostly in no change to the protein codes for, or genetic variants of the protein
Mutations occur continuously

Question 2

Describe the effect of a gene mutation in coding DNA

Answer 2

If a mutation changes the amino acid sequence, protein structure and function may change (enzyme no longer fit substrate, structural protein lose strength)

If a mutation does not change amino acid sequence, there is no effect on protein structure or sequence

Question 3

What is non-coding DNA

Answer 3

DNA which does not code for a protein but instead controls gene expression

Question 4

Describe the effect of a gene mutation in non-coding DNA

Answer 4

Gene expression may be altered. affecting protein production and the resulting phenotype

Question 5

What are alleles

Answer 5

Different versions of the same gene

Question 6

What is a dominant allele

Answer 6

A version of a gene where only one copy is needed for it to be expressed

Question 7

What is a recessive allele

Answer 7

A version of a gene where two copies are needed for it to be expressed

Question 8

What is meant when an organism is homozygous

Answer 8

When an organism has 2 copies of the same allele

Question 9

What is meant when an organism is heterozygous

Answer 9

When an organism has 2 different versions of the same gene

Question 10

What is the genotype

Answer 10

The genes present for a trait

Question 11

What is the phenotype

Answer 11

The visible characteristics

Question 12

What is the problem with single gene crosses

Answer 12

Most characteristics are controlled by multiple alleles rather than just one

Question 13

What is an inherited disorder

Answer 13

A disorder caused by the inheritance of certain alleles

Question 14

How are embryos screened for inherited disorders

Answer 14

During IVF, one cell is removed and tested for disorder-causing alleles
If the cell doesn’t have any indicator alleles then the originating embryo is implanted into the uterus

Question 15

What are the ethical issues concerning embryo screening

Answer 15

It could lead to beliefs in society that being disabled or having a disorder is less human or associated with inferiority

The destruction of embryos with inherited disorders is seen by some as murder

Question 16

Economic issues concerning embryo screening

Answer 16

Costs of hospital treatment and medication will need to be considered if it is known that a child will have an inherited disorder and financial support explored if necessary

Question 17

Social issues concerning embryo screening

Answer 17

Social care for children with inherited disorders may need to be considered if parents are unable to provide care
If an embryo is found to have an inherited disorder and is terminated this can prevent a child and its parents from potential suffering in the future