8: Genetics

Question 1

two types of radiation that can cause mutations

Answer 1

high energy radiation, like UV
ionising radiation, like X rays, Gamma rays

Question 2

the genetic code is what—–

Answer 2

degenerate

Question 3

example of a nonsense mutation

Answer 3

cycstic fibrosis

Question 4

what is a genotype

Answer 4

combination of alleles found in an organism at a particular gene

Question 5

what is PKU caused by

Answer 5

a mutation in an autosomal gene that codes for the enzyme needed to convert phenylalanine to tyrosine

Question 6

what is a codominant allele

Answer 6

two alleles that both contribute to the phenotype in a heterozygous individual

Question 7

which pair of chromosomes are sex chromosomes

Answer 7

23rd

Question 8

what are the three types of gene mutation

Answer 8

substitution, deletion, insertion

Question 9

nonsense mutations:

Answer 9

creates a premature stop codon, no functional protein is made

Question 10

what is a gene locus

Answer 10

place gene is found on a chromosome

Question 11

cancer starts how

Answer 11

mutation in gene that causes cell division- oncogene, or in tumour supresser genes

Question 12

what is the result of base substitution

Answer 12

SNP’s formed

Question 13

what do SNP’s stand for

Answer 13

single nucleotide polymorphisms

Question 14

cancer occurs from uncontrolled what

Answer 14

uncontrolled mitosis, forming a tumour

Question 15

2 examples of chemical substances that can cause mutations

Answer 15

carcinogens found in tobacco smoke
mustard gas from WW1

Question 16

what is a gene mutation

Answer 16

a change in the sequence of base pairs in a DNA molecule

Question 17

example of disease involved in inheriting recessive alleles

Answer 17

phenylketonuria, PKU

Question 18

2 types of mutagenic agents

Answer 18

chemical substances, radiation

Question 19

substitution mutations can take three forms :

Answer 19

silent mutations
missense mutations
nonsense mutations

Question 20

which cell, germ or somatic, is cancer related to

Answer 20

somatic

Question 21

example of a missense mutation

Answer 21

sickle cell anaemia

Question 22

example of phenotypic plasticity in humans

Answer 22

skin colour, enzymes activated in UV light increase expression/production of melanin

Question 23

deletion and insertion have an effect on the rest of the sequence known as a

Answer 23

frameshift mutation

Question 24

example of mutation hotspots are regions were it is more frequent, give an example

Answer 24

c-g
can turn into c-t
called methylation
associated with colorectal cancer

Question 25

a germ cell uses waht:

Answer 25

meiosis to produce gametes

Question 26

what is a test cross

Answer 26

a cross with a homozygous recessive organisms that tells you whether a dominant trait organism is hetero or homozygous

Question 27

what is sex linkage

Answer 27

when the gene controlling the characteristic is located on the sex chromosome

Question 28

example of incomplete dominance

Answer 28

mirabilis jalapa, red and white flowers creates pink

Question 29

what is substitution mutation

Answer 29

when a nucleotide base in DNA is randomly swapped for a different base

Question 30

what is deletion mutation

Answer 30

a nucleotide is randomly deleted from the sequence

Question 31

what is insertion mutation

Answer 31

a nucleotide with a new base is randomly inserted into DNA sequence

Question 32

what is the name for environmental factors that increase the mutation rate of cells

Answer 32

mutagenic agents

Question 33

what is a phenotype

Answer 33

appearance/characteristic of an organism

Question 34

what is phenotypic plasticity

Answer 34

although genotype remains fixed, phenotype expressed can vary

Question 35

what is the only source of variation for asexual species

Answer 35

mutations

Question 36

oncogene?

Answer 36

gene that has potential to cause cancer

Question 37

feature of genetic code that means silent mutations can happen

Answer 37

degenerate

Question 38

what needs to be inherited for a child to inherit PKU

Answer 38

2 recessive alleles

Question 39

which three locations are most likely for mutations to occur

Answer 39

uncoiled DNA non coding regions mutation hotspots

Question 40

what is a gene

Answer 40

a sequence of a DNA molecule that codes for a protein or characteristic

Question 41

missense mutation:

Answer 41

alters single amino acid, still codes a protein

Question 42

does the y or x chromosome have few genes

Answer 42

y

Question 43

what is a recessive allele

Answer 43

An allele that only affects the phenotype when present in the homozygous state.

Question 44

what does degenerate mean?

Answer 44

more codons than amino acids, mutations won't always cause change in DNA sequence

Question 45

multiple alleles mean what

Answer 45

many genes can exist in multiple forms

Question 46

are body cell mutations inherited?

Answer 46

no, mutations within a gamete are

Question 47

what is a dominant allele

Answer 47

an allele that has the same effect on a phenotype whether is is homo/heterozygous

Question 48

what are the three alleles of blood groups

Answer 48

IA, IB, i

Question 49

example of phenotypic plasticity in animals

Answer 49

Himalayan rabbit, gene expression is influenced by temperature. parts of body that are cooler- black fur- ears feet nose

Question 50

what is an example of a multiple allele

Answer 50

blood group

Question 51

what is an allele

Answer 51

an alternative version of a gene

Question 52

which molecule detects errors during DNA replication and repair

Answer 52

DNA polymerase

Question 53

a somatic cell uses what

Answer 53

mitosis to produce body cells