4.3 Inheritance

Question 1

What is the definition of allele?

Answer 1

Variations of the same gene

Question 2

What is the definition of gene?

Answer 2

A section of DNA that codes for a polypeptide

Question 3

What is the definition of dominant?

Answer 3

Will be expressed in even when heterozygous

Question 4

What is the definition of recessive?

Answer 4

Only expressed when homozygous

Question 5

What is the definition of phenotype?

Answer 5

Physical expression of a gene

Question 6

What is the definition of genotype?

Answer 6

Combination of alleles

Question 7

What is the definition of homozygous?

Answer 7

Alleles for a characteristic are the same

Question 8

What is the definition of heterozygous?

Answer 8

Alleles for a characteristic that are different

Question 9

What is Mendals first law?

Answer 9

Law of segregation
All characteristics are determined by alleles tat occur in pairs
only one form each pair can be present in a single gene

Question 10

What is Mendals second law?

Answer 10

Law of independent assortment
Each pair of alleles may combine randomly with either of another pair

Question 11

What is Dihybrid inheritance?

Answer 11

The simultaneous inheritance of two alleles determined by two genes on different chromosomes

Question 12

What ratio did Mendal conclude for F2?

Answer 12

9:3:3:1

Question 13

What is a test cross?

Answer 13

Crossing dominant phenotypes wit homozygous recessive

Question 14

When is H0 rejected?

Answer 14

If the result exceeds the critical value and is therefore significant

Question 15

What are the exceptions to mendals law?

Answer 15

Co-dominant alleles
Sex linked genes
Non independent assortment

Question 16

What is sex linkage?

Answer 16

Alleles linked to the X or Y chromosome

Question 17

What are some examples of sex linked diseases?

Answer 17

Red/green colour blindness
Haemophilia

Question 18

What is codominance?

Answer 18

When alleles are expressed equally in the phenotype (e.g. Red, pink and white)

Question 19

What us a mutation?

Answer 19

a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide

Question 20

What is an ancogene?

Answer 20

A mutation allowing cells to divide uncontrollably

Question 21

What is a mutagen?

Answer 21

A factor causing a mutation

Question 22

What is a Insertion/deletion mutations? And what is it impact?

Answer 22

When 1 or more nucleotide pairs are inserted or deleted from the sequence
Causes a frameshift in the sequence of nucleotides

Question 23

What is point mutation/substitution?

Answer 23

where one base pair is replaced by another

Question 24

What is an Oncogene?

Answer 24

A gene that can develop into a tumor

Question 25

What is the impact of cancer to the body?

Answer 25

Inhibited bodily functions

Question 26

What is the impact of cancer to the body?

Answer 26

Inhibited bodily functions

Question 27

How is sickle cell anaemia caused?

Answer 27

A gene mutation to the gene producing haemoglobin Glutamic acid is replaced with valine Polypeptide chain is altered producing Haemoglobin S

Question 28

How is sickle cell anaemia inherited?

Answer 28

Mutated gene is codominant Homozygous = sufferer Heterozygous= 30-40% chance of suffering

Question 29

What are the symptoms of sickle cell?

Answer 29

RBC carrying capacity decreased joint pain organ damage distorted blood vessels

Question 30

What is a silent mutation?

Answer 30

Multiple codons for 1 amino acid so sequence changes but not amino acid produced

Question 31

What is epigenetics?

Answer 31

Control of gene expression with factors outside of sequencing

Question 32

What is methylation of cytosine?

Answer 32

Histone modification after translation nucleosomes pack less tightly making histones more accessible and therefore more transcription occurs

Question 33

What are the consequences of epigenetic changes?

Answer 33

genomic imprinting x inactivation

Question 34

What is genomic imprinting?

Answer 34

Inactivation of a gene/genes passed down generations leading to permeant switching off and genetic conditions

Question 35

What is X inactivation?

Answer 35

Whole chromosome inactivation cells of female mamals will use only one X chromone and the other dense chromatin Barr body

Question 36

What does epigenetics control?

Answer 36

How likely transcriptions are Post transcription alterations

Question 37

What factors impact epigenetics?

Answer 37

Lifestyle mental health Physical health Weather chemical or biological exposure

Question 38

What is an epigenome?

Answer 38

The accumulation of environmental signals received in life

Question 39

What is Hyper-methylation?

Answer 39

Tumour suppressant inhibited so no control of tumour growth

Question 40

What is hypo-methylation?

Answer 40

lack of methylation

Question 41

What is hypo-methylation?

Answer 41

lack of methylation

Question 42

What is hypo-methylation?

Answer 42

lack of methylation