B1

Question 1

The instructions to control how an organisms develop an function are called what and are found where?

Answer 1

They are called genes and they are found in the nucleus of a cell

Question 2

Genes are instructions for a cell that describe what?

Answer 2

How to make proteins

Question 3

What are the two types of enzymes an give an example for each?

Answer 3

Structural ie collagen

Functional ie enzymes such as amylase

Question 4

What is a gene?

Answer 4

A section of a very long DNA molecule

Question 5

What is a chromosomes?

Answer 5

Chromosomes are long,coiled molecules of DNA

Question 6

Give examples of features determined by environmental factors genetic factors and a combination of both?

Answer 6

Scars. Dimples, Weight

Question 7

Which two factors determine the characteristics of an organism?

Answer 7

Environmental factors and genetic factors

Question 8

Give an example of a characteristic that is several working together?

Answer 8

Eye colour

Question 9

In terms of chromosomes describe the difference between body cells and sex cells?

Answer 9

Body cells contain pairs of chromosomes,(23 pars, 46 chromosomes) but sex cells contain only one chromosome from each pair (23 single chromosomes)

Question 10

What is the name for different versions of the same gene?

Answer 10

Alleles

Question 11

How many alleles does an individual usually have for each gene?

Answer 11

Two

Question 12

What are terms used for the same alleles and for different alleles of the same gene?

Answer 12

Homozygous and Heterozygous

Question 13

Why do offspring not look identical to one parent?

Answer 13

Because genes from different parents come together to produce variation in their offspring

Question 14

Why do offspring have some similarities to their parents?

Answer 14

Because genes from their parents combine in fertilisation of the egg cell

Question 15

Why don’t all off spring look identical to their brothers and sisters?

Answer 15

They inherit a different combination of alleles from their mother and father.

Question 16

If an individual has one or both dominant alleles will they show the associated dominant characteristics?

Answer 16

Yes.

Question 17

If an individual has one recessive alleles, will they show the associated recessive characteristics?

Answer 17

No.

Question 18

If an individual has both recessive alleles, will they show the associated recessive characteristics?

Answer 18

Yes

Question 19

Recall the sex chromosomes for males and females?

Answer 19

Males are XY and females are XX

Question 20

Where is the sex-determining gene located?

Answer 20

On the Y chromosome.

Question 21

What does the sex-determining gene on the Y chromosome trigger?

Answer 21

The development of the testes

Question 22

What does an absence of a Y chromosomes trigger?

Answer 22

the development of ovaries

Question 23

What does the term genotype mean?

Answer 23

It is used to describe the genetic make up of an individual (the gene that someone has )

Question 24

What does phenotype mean?

Answer 24

It is used to describe the observable characteristics that an individual has

Question 25

Give two example of a faulty allele of a single gene.

Answer 25

Cystic fibrosis and Huntington's diease

Question 26

What disease is caused by a faulty dominant allele?

Answer 26

Huntington dieases

Question 27

What diseases is caused by a faulty recessive alelle?

Answer 27

Cystic fibrosis

Question 28

Give three symptoms of Huntington's diease

Answer 28

Tremors, Clumsiness, Memory loss, Inability to concentrate

Question 29

Give three symptoms of Cystic fibrosis

Answer 29

Thick mucus, Difficulty breathing Chest infections Difficulty in digesting foods

Question 30

Can someone be a carrier of a dominant disorder? Why?

Answer 30

No, Because if someone has one allele they will show the characteristics of the faulty disorder.

Question 31

Can someone be a carrier of the recessive gene? Why?

Answer 31

Yes, Because if they have one recessive allele they will not show the symptoms of the disease but they could pass it on to their children

Question 32

List five considerations that must be made when testing adults and foetuses for alleles that cause genetic disorder

Answer 32

- Risk of miscarriage as a result of cell sampling - False positive and negatives - Whether or not to have children as a result of the tests - Whether or not to have the pregnancy terminated - Whether other members of the family should be informed

Question 33

Describe two implications of testing embryos for embryo selection prior to implantations

Answer 33

1. The possibility of designer babies | 2. some embryos will be destroyed

Question 34

Describe the implications of the use of genetic testing by employers and insurance companies

Answer 34

- People may lose their jobs - Employers may be able to cater for the person needs better - Insurance may be hard to get - Insurance may be expensive - People may not get job

Question 35

What is a clone?

Answer 35

An individual with identical genes with another

Question 36

Name two organisms that produces asexually to form clones

Answer 36

Bacteria and plants

Question 37

What factor can contribute to differences between clones?

Answer 37

Environmental factors

Question 38

How can a clone in an animal form naturally?

Answer 38

When cells of an embryo seperate to form identical twins

Question 39

How can a clone of an animal be made artificially?

Answer 39

By using the nucleus of an adult body cell and transferring it to an empty unfertilised cell and implanting it into a female's uterus

Question 40

Describe an adult stem cell

Answer 40

An unspecialised cell that can develop in many, but not all, types of cell.

Question 41

Describe an embryonic stem cell

Answer 41

It is unspecialised cell that can develop into any type of cell

Question 42

Why do adult and embryonic stem cells have the potential to treat diseases?

Answer 42

Because they are unspecialised stem cells they may be treated so they can divide into tissue organs and that can replace or change the functionality of existing tissues and organs within a organisnms

Question 43

In multicellular organisms, when do the majority of cells become specialised?

Answer 43

During the early development (embryo- foetus)