Module 2 - Genetics/Inheritance

Question 1

One of the smallest biological units of heredity located in DNA; transmits hereditary information

Answer 1

Gene

Question 2

Bar-like bodies of tightly coiled chromatin; visible during cell division. Formed with the nucleus by the super-coiling of DNA

Answer 2

Chromosome

Question 3

Two matched genes at the same location (locus) on the chromosome

Answer 3

Allele

Question 4

Location

Answer 4

Locus

Question 5

A pair of morphologically identical chromosomes that carry genes for the same traits

Answer 5

Homologous

Question 6

Having identical genes at one or more loci

Answer 6

Homozygous

Question 7

Having different allelic genes at a given locus or (by extension) many loci

Answer 7

Heterozygous

Question 8

One’s genetic make-up or genes

Answer 8

Genotype

Question 9

Observable expression of the genotype

Answer 9

Phenotype

Question 10

Occurs when one allele masks or suppresses the expression of its partner

Answer 10

Dominant trait

Question 11

A trait due to a particular allele that does not manifest itself in the presence of other alleles that generate traits dominant to it; must be present in double dose to be expressed

Answer 11

Recessive trait

Question 12

How many chromosomes do humans have?

Answer 12

23 pairs of homologous chromosomes

Question 13

How many autosomes do humans have?

Answer 13

44

Question 14

How many sex chromosomes do humans have?

Answer 14

2

Question 15

What do autosomes do?

Answer 15

Guide expression of traits

Question 16

What do sex chromosomes do?

Answer 16

Determine genetic sex

Question 17

The number and size of chromosomes in a cell is the ———-

Answer 17

Karotype

Question 18

All somatic cells of an organism have the same ———-

Answer 18

Karotype

Question 19

Allele code for ——— or ———— form of trait

Answer 19

same; different

Question 20

If two allele code for same trait =

Answer 20

homozygous

Question 21

If two allele different =

Answer 21

heterozygous

Question 22

What are the 5 different types of inheritance?

Answer 22

Autosomal dominant/recessive
Sex-linked inheritance
Multiple allele
Incomplete dominance
Polygenic

Question 23

Name 3 examples of traits that are expressed by dominant genes

Answer 23

Freckles
Normal skin pigment
Dimples in cheeks

Question 24

Name 3 examples of traits that are expressed recessive genes

Answer 24

Albinism
Flat feet
Attached earlobes

Question 25

Inherited traits determined by genes on sex chromosome

Answer 25

Sex-linked inheritance

Question 26

A gene found only on the X-chromosome

Answer 26

X-linked

Question 27

A gene found only on the Y-chromosome

Answer 27

Y-linked

Question 28

2 examples of sex-linked traits

Answer 28

colour blindness

Haemophilia

Question 29

Name 3 types of colour blindness

Answer 29

protanopia
deuteranopia
tritanopia

Question 30

Which blood groups are dominant?

Answer 30

IA and IB

Question 31

Which blood group is recessive?

Answer 31

i

Question 32

How many alleles are there for blood group?

Answer 32

3

Question 33

What are the 4 blood groups?

Answer 33

A, B, AB, and O

Question 34

Both alleles expressed in heterozygous to produce different phenotype to either homozygous, often an intermediate is an example of ———— ———-

Answer 34

Incomplete dominance

Question 35

2 example of traits that can involve incomplete dominance

Answer 35

Hair texture

Flower colour

Question 36

Some traits require several gene pairs

Answer 36

Polygenic inheritance

Question 37

2 examples of traits that involve polygenic inheritance

Answer 37

Skin colour

Eye colour

Question 38

An example of an autosomal recessive disease

Answer 38

Cystic fibrosis

Question 39

An example of a co-dominant genetic disease

Answer 39

Sickle cell anaemia

Question 40

An example of a X-linked recessive disease

Answer 40

Haemophilia

Question 41

Trisomy 21

Answer 41

Down’s syndrome