Human Genetics

Question 1

What is genetics?

Answer 1

the biological study of hereditary, attempting to predict the characteristics of offspring from mating

Question 2

Name the 2 processes of cellular reproduction

Answer 2

meiosis

mitosis

Question 3

Which process is used in the reproduction of sex cells (ova/egg and sperm(?

Answer 3

meiosis

Question 4

Which process is used in the reproduction of eukaryotic cells?

Answer 4

mitosis

Question 5

Describe the process of mitosis

Answer 5

a cell doubles its DNA, then splits into 2 identical daughter cells, each with 46 chromosomes (23 pairs)

Question 6

Describe the process of meisos

Answer 6

a cell duplicates its DNA, then splits into 4 non-identical daughter cells, each with 23 chromosomes

Question 7

What term means a cell has 23 chromosomes (half the amount of a eukaryoctic cell)

Answer 7

haploid

Question 8

Which term means a cell has 46 chromosomes?

Answer 8

diploid

Question 9

How many chromosomes does a diploid cell have?

Answer 9

46

Question 10

How many chromosomes does a haploid cell have?

Answer 10

23

Question 11

What name is given to the reproduction of sex cells such as ova and sperm?

Answer 11

meiosis

Question 12

What is a gene?

Answer 12

a unit of hereditary on a pair of chromosomes

Question 13

What is an allele?

Answer 13

half a gene, or the location of a characteristic on 1 chromosome

Question 14

What does homozygous mean?

Answer 14

having two dominant or recessive alleles (both are the same)

Question 15

What does heterozygous mean?

Answer 15

having 1 dominant and 1 recessive allele (one of each)

Question 16

What does dominat mean?

Answer 16

if a dominant allele is present it displays the characteristic in the individual

Question 17

What does reessive mean

Answer 17

that you need to have 2 of the same alleles to show the characteristic

Question 18

Which term means that you have 2 of the same alleles?

Answer 18

homozygous

Question 19

Which term means that you have 1 of each allele?

Answer 19

heterozygous

Question 20

What is a punnet square?

Answer 20

a diagram used to determine the probability of an offspring haing a particular genotype

Question 21

What is a phenotype?

Answer 21

the outward display of a characteristic (what you see)

Question 22

What is a genotype?

Answer 22

the individual’s make up of genes

Question 23

What is a gamete?

Answer 23

a sex cell (sperm or ova/egg)

Question 24

What is a zygote?

Answer 24

the cell produced when a sperm has fertilised an ovum (egg) which contains 1/2 it’s DNA from each - it has 46 chromosomes

Question 25

Is Cystic Fibrosis a dominant or recessive gene?

Answer 25

recessive

Question 26

Is Phenylketonuria a dominant or recessive gene?

Answer 26

recessive

Question 27

Is Sickle Cell Disease a dominant or recessive gene?

Answer 27

partially dominant

Question 28

Is Huntington's Disease a dominant or recessive gene?

Answer 28

dominant

Question 29

What is Phenylketonuria?

Answer 29

where the body is unable to break down the amino acid phenylalanine, which builds up, leading to brain damage

Question 30

What is sickle cell disease?

Answer 30

where red blood cells develop abnormally, so they can block blood vessels, resulting in tissue and organ damage

Question 31

What is cystic fibrosis?

Answer 31

where your lungs and digestive system become clogged with thick, sticky mucous, causing respiratory infections

Question 32

What is Huntington's Disease?

Answer 32

a condition which damage nerve cells in the brain, affecting movement, cognition, balance, awareness, judgement and mood

Question 33

What's the probability of a child being born to 2 parents with phenylketonuria, having it?

Answer 33

100% | As its a recessive gene, both parents would be pp, so all children would be pp

Question 34

What's the probability of a child being born to 1 homozygous PKU, and 1 heterozygous non-PKU parent? (draw the punnet square to help you)

Answer 34

50% PKU | 50% - unaffected carrier

Question 35

What are the possible genotypes of a person without PKU?

Answer 35

PP - homozygous non-PKU | Pp - heterozxygous non-PKU (these are carriers)

Question 36

What's the probability of a child having PKU if they are born to 2 homozygous parents, 1 PKU, 1 non-PKU,

Answer 36

100% non-PKU (carriers)

Question 37

What's the probability of a child having Huntington's Disease if they are born to 2 heterozygous Huntington's parents

Answer 37

75% Huntington's 25% - HH 50% - Hh 25% - hh

Question 38

What's the probability of a child having Huntington's Disease if they are born to a homozygous Huntington's and homozygous non-Huntington's parents?

Answer 38

100% Huntington's | all Hh

Question 39

If someone is heterozygous for Sickle Cell disease, what does that mean?

Answer 39

They have sickle cell trait (which means they're 50% likely to get the symptoms of sickle cell disease)

Question 40

Which genetic disease is carried on a dominant gene?

Answer 40

Huntington's disease

Question 41

Which genetic diseases are carried on recessive genes?

Answer 41

Cystic Fibrosis | Phenylketonuria

Question 42

Which genetic disease is partially dominant?

Answer 42

Sickle cell disease

Question 43

Identify 2 diagnostic tests that can be used to test if a foetus will be born with certain genetic diseases?

Answer 43

amniocentesis | chorionic villus sampling

Question 44

Describe amniocentesis

Answer 44

a long, thin needle is inserted through your abdominal wall, guided by an ultrasound image. A small sample of amniotic fluid is removed for analysis.

Question 45

Describe Chorionic Villus Sampling

Answer 45

a tube or small forceps are inserted through the cervix and a small sample of cells is removed from the placenta