Variation and Genetics

Question 1

What do genes control

Answer 1

Characteristics

Question 2

What are versions of genes called?

Answer 2

Alleles

Question 3

If both the alleles have the same for a particular gene, what is this called?

Answer 3

Homozygous

Question 4

If both the alleles are different for a particular gene, what is this called?

Answer 4

Hetrozygous

Question 5

If the 2 alleles for a particular gene are the same (Aa), which one determines the characteristic developed?

Answer 5

The dominant one (Capital letter)

Question 6

For an organism to express its recessive characteristic, what must be true about both alleles?

Answer 6

They must both be recessive (aa)

Question 7

For an organism to express its dominant characteristic, what must be true about both alleles?

Answer 7

There must be at least 1 dominant allele, but could be true (Aa or AA)

Question 8

What is your genotype?

Answer 8

Which alleles you have

Question 9

What is your phenotype?

Answer 9

Which characteristics you have

Question 10

What are the 2 types of variation?

Answer 10

Genetic and environmental

Question 11

What causes genetic variation?

Answer 11

Different genes

Question 12

What is an organism’s characteristics determined by?

Answer 12

The genes inherited from their parents

Question 13

What are characteristics of an organism influenced by?

Answer 13

The environment e.g hot or cold

Question 14

What is a chromosome?

Answer 14

A long strand of DNA

Question 15

What is a gene?

Answer 15

A section of DNA

Question 16

What does a gene do?

Answer 16

Codes for a particular combination of amino acids which make a specific protein

Question 17

How many amino acids are used in a gene?

Answer 17

20

Question 18

What are the 4 bases?

Answer 18

A T C G

Question 19

What does the order of bases in a gene determine?

Answer 19

The order of amino acids in that protein

Question 20

What chromosomes do men have?

Answer 20

XY

Question 21

What chromosomes do women have?

Answer 21

XX

Question 22

What is your genotype?

Answer 22

Which alleles you have

Question 23

What is your phenotype?

Answer 23

Which genes you have

Question 24

What is cystic fibrosis caused by?

Answer 24

Recessive allele

Question 25

What is cystic fibrosis?

Answer 25

A genetic disorder of the cell membranes. A lot of mucus is produced in air passages and pancreas

Question 26

What is polydactyly caused by?

Answer 26

Dominant allele

Question 27

What is polydactyly?

Answer 27

When someone is born with extra fingers or toes

Question 28

What is sickle-cell anaemia caused by?

Answer 28

Recessive allele

Question 29

What is sickle-cell anaemia?

Answer 29

When RBCs get stuck in capillaries which deprives the body of oxygen

Question 30

How does embryonic screening work?

Answer 30

DNA is isolated, then a gene probe is labelled and is put into the DNA mix and will bind to a specific allele. When a UV lamp is shone, the probe can be seen.

Question 31

When doing embryonic screening, how do you know if the genetic disorder is present?

Answer 31

The probe will have stuck

Question 32

What is a genetic probe?

Answer 32

A short section of DNA which will bind to the allele for the disorder

Question 33

What are some reasons for embryonic screening?

Answer 33

Stop suffering Treating disorders costs the Gov a lot of money Laws stop it from going too far

Question 34

What are some reasons against embryonic screening?

Answer 34

Implies people with genetic problems are undesirable Expensive May come a point where everyone will want "designer babies"

Question 35

What is sexual reproduction?

Answer 35

The fusion of a male and female gamete. Because there are 2 parents, the offspring contains a mixture of their parents genes

Question 36

What is asexual reproduction?

Answer 36

No fusion of gametes or mixing of chromosomes -> No genetic variation. The offspring are clones

Question 37

Name some examples of organisms which reproduce asexually

Answer 37

Plants, bacteria and some animals

Question 38

Describe the process for adult cell cloning

Answer 38

Taking an unfertilised egg cell and removing the nucleus. A diploid cell from another adult body is inserted into the egg cell. An electric shock then causes the cell to undergo division. Then implanted into a surrogate mother

Question 39

What are some disadvantages to cloning?

Answer 39

If a disease comes around, whole population is dead Study into age-related disorders Some people worry humans may be cloned

Question 40

What do the enzymes do in GE?

Answer 40

Cut and paste genes

Question 41

Describe the process of GE and producing insulin

Answer 41

Insulin gene gut out and put into a plasmid. The bacteria then reproduce like crazy

Question 42

What are some disadvantages to GM crops?

Answer 42

Affect biodiversity, unsure whether it is safe, transplanted genes may get out into the natural environment

Question 43

What are some advantages to GM crops?

Answer 43

Increase yield of the crop GM crops could be engineered to give nutrients which people lack Already being grown with no problems