Mendels Law And Non Mendelian Inheritance

Question 1

What plant did Mendel use to study heredity

Answer 1

Garden peas

Question 2

Why did Mendel choose to work with garden peas

Answer 2

They have short generation time, different observable traits, could control mating, cheap easy and can grow fast

Question 3

What type of fertilization do peas normally use

Answer 3

Self-fertilization

Question 4

How does self-fertilization work

Answer 4

Male organ (stamen) produces pollen grains which make sperm

Female organs (carpels) produces pollen grains eggs

A flowers pollen grain falls on its own female organ and fertilizes the egg

Question 5

How did Mendel prevent self fertilization

Answer 5

Removed male organ

Question 6

I have a homozygous dominant purple plant and a recessive white plant, what will my phenotypic and genotyping ratios be if i cross them

Answer 6

100% purple
100% heterozygous

Question 7

What is an allele

Answer 7

Variations in a genes nucleotide sequence

Question 8

What is the law of segregation

Answer 8

Two alleles for one heritable factor separate during gamete formation

Question 9

What is homozygous

Answer 9

Having two identical alleles

Question 10

What is heterozygous

Answer 10

Having two different alleles

Question 11

What is phenotype

Answer 11

The physical appearance, internal anatomy, physiology or behaviour associated with a genotype

Question 12

What is a genotype

Answer 12

An organisms genetic makeup

Question 13

What is a monohybrid cross

Answer 13

A genetic cross between parents who are both heterozygous for a trait

Question 14

What is a dihybrid cross

Answer 14

A genetic cross between parents that are heterozygous for two traits

Question 15

What is complete dominance

Answer 15

Heterozygous and dominant homozygous produce the same phenotype

Question 16

What is incomplete dominance

Answer 16

When heterozygous phenotype is somewhere between the homozygous ones (the traits are blended)

Question 17

What is co-dominance

Answer 17

Two alleles are equally dominant so if you cross a red and a white flower you get a flower with both red and white pedals

Question 18

What is multiple alleles

Answer 18

When a gene has more than 2 alleles such as blood type with IA IB and i

Question 19

What is epistasis

Answer 19

Two or more genes affect one genotype, expression of one gene interferes with the other

Question 20

What is an epistatic factor

Answer 20

The gene that suppresses the other gene

Question 21

What is the phenotypic ratio of a recessive epistatic dihybrid cross

Answer 21

9:4:3

Question 22

What is pleiotropy

Answer 22

Single gene with multiple phenotypic effects

Question 23

What is norm of reaction

Answer 23

The phenotypic range a genotype can be influenced by the environment

Question 24

Marian syndrome is the result of what type of inheritance

Answer 24

Pleiotropy

Question 25

In Mendelian inheritance each phenotypic trait is

Answer 25

Monogenic

Question 26

What does it mean to be monogenic

Answer 26

Expression of a trait is either dominant or recessive

Question 27

What is polygenic inheritance

Answer 27

One phenotype is controlled by more than one gene which affect each other quantitatively

Question 28

Some examples of polygenic inheritance

Answer 28

Hair colour, skin colour, height, eye colour

Question 29

What is intragenic interaction

Answer 29

Two alleles on the same locus interact to produce a modified genotype (incomplete dominance, codominance, multiple alleles)

Question 30

Intergenic interaction

Answer 30

A gene on one locus interacts with another gene in a different locus or different chromosome (epistasis and polygenic inheritance)

Question 31

Epistatic vs hypostatic gene

Answer 31

The epistatic gene masks the hypostatic gene

Question 32

Describe recessive epistasis

Answer 32

When the epistatic gene is recessive it masks the hypostatic gene

Question 33

Describe dominant epistasis

Answer 33

When the epistatic gene is dominant it masks the hypostatic gene

Question 34

What is the phenotypic ratio of a dihybrid cross with dominant epistasis

Answer 34

12:3:1

Question 35

Complementary epistasis is also called

Answer 35

Duplicate recessive epistasis

Question 36

Describe complementary/duplicate recessive epistasis

Answer 36

When either gene is recessive it masks the dominant phenotype, (to get the dominant phenotype you need C-P-)

Question 37

What is the phenotypic ratio of complementary epistasis of a dihybrid cross

Answer 37

9:7

Question 38

Describe duplicate dominant epistasis

Answer 38

Dominant alleles at both loci produce same phenotype (need aabb to see different phenotype)

Question 39

What is the phenotypic ratio of a duplicate dominant epistasis dihybrid cross

Answer 39

15:1

Question 40

Describe polymeric gene interaction epistasis

Answer 40

Both dominant genes control the same phenotype and if they are both dominant the phenotype is enhanced (if aabb codes for a long plant and A-bb or aaB- code for a spherical plat A-B- will code for a disk plant since both of the dominant genes are shortening the plant)

Question 41

What is the phenotypic ratio for a dihybrid cross of polymeric gene interaction epistasis

Answer 41

9:6:1

Question 42

What is a wild type gene

Answer 42

The most common phenotype or genotype among wild animals

Question 43

A phenotype or genotype which is not wild type is called

Answer 43

A variant or a mutant

Question 44

What is an example of age dependent gene expression

Answer 44

Human male pattern baldness, adult-onset Huntington’s disease

Question 45

What are the three categories for sex traits

Answer 45

Sex-limited, sex-linked, sex-influenced

Question 46

What are sex-limited traits

Answer 46

Traits only visible in one sex, such as feathering in chickens (rooster feathering is only expressed in males)

Question 47

What are sex-linked traits

Answer 47

Traits generally influenced by genes on the X chromosome such as colour blindness

Question 48

What are sex-influenced traits

Answer 48

Traits controlled by genes on autosomes, the phenotype is possible in both sexes but the expression varies, such as male pattern baldness (BB and Bb produce baldness in men but only BB produces it in women)

Question 49

What is temperature dependent gene expression with example

Answer 49

Phenotype dependent on temperature, usually due to affecting the protein produced by the genotype. Himalayan rabbits mainly the c^h allele which develops pigments which functions in colder parts of the body

Question 50

What 4 concepts explained the 3:1 ratio (Mendel)

Answer 50

Alternate versions of genes (alleles) account for variations in inherited characteristics For each character an organism inherits on allele from each parent If the alleles differ the dominant one decides the characteristic The two alleles for a characteristic separate during gamete formation