Mendel's Laws of Heredity

Q. Explain how is it possible for brown eyed parents to have a blue-eyed child. Which law does it illustrate? [5 MARKS]

Q.

The genes controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes?

1. 5

2. 6

3. 4

4. 7

Q.

Which of the given traits of pea plants selected by Mendel expresses itself only in homozygous conditions? Terminal flower, green seed, yellow pod, constricted pod, violet petals, dwarf stem.

Q.

What is the genotypic and phenotypic ratio of the monohybrid test cross?

1. $2:1$

2. $1:2$

3. $1:1$

4. $2:1:1$

Q.

A homozygous purple flower variety of pea plant [PP] is crossed with a white flower variety of pea[pp]. Answer the following questions by using Punnett square:-
i) Mention the phenotype and genotype of the F1 and generation offsprings.
ii) If the offsprings of the F1 and generation are crossed, what will be the phenotypic ratio and genotypic ratios of the F2 generation?
iii) State Mendel's Law of dominance.
​​​​​​iv) What is the scientific name of the pea plant?
v) Name two genetic diseases in humans

Q. Explain the law of segregation with suitable example.(please provide the punnet square also).

Q. Assertion [A]: A geneticist crossed two plants. He got 50% tall and 50% dwarf plants in the progeny.

Reason [R]: One parent was heterozygous tall while the other was dwarf.

1. Both A and R are true and R is the correct explanation of A.
2. A is true but R is false.
3. Both A and R are true but R is not the correct explanation of A.
4. Both A and R are false.

Q.

What are the similarities of incomplete dominance and codominance?

Q. Some humans are able to roll their tongue, while others are not. Two parents (both tongue-rollers) have children where not all are tongue-rollers. Which of the following statements hold true regarding this?

1. The gene for tongue-rolling is dominant.
2. The probability that their child will be a tongue-roller is 0.5.
3. The probability that their child will not be a tongue-roller is 0.75.
4. Both parents are heterozygous for tongue-rolling.

Q.

A pure round seed plant is crossed with the pure wrinkled seed plant. The genotypic ratio shall be______.

1. 1:1:1

2. 2:1:1

3. 1:2:1

4. 3:1:1

Q.

Mendel’s laws were rediscovered by

1. Sutton and Boveri

2. T.H. Morgan and Bridges

3. Hugo de Vries, Carl Correns and Erich Von Tschermak

4. Waldeyer and Hofmeister

Q.

Haploids are more suitable for mutation studies than the diploids. This is because:

1. haploids are more abundant in nature than diploids

2. haploids are reproductively more stable than diploids

3. all mutations, whether dominant or recessive, are expressed in haploids

4. mutagens penetrate in haploids more effectively than in diploids

Q. Which are the contrasting characters that Mendel observed in pod of a pea plant?

1. Length
2. Colour
3. Shape
4. Position

Q. Haploid plants are preferred over diploids for mutation study because in haploids

1. Induction of mutation is easier
2. Culturing is easier
3. Recessive mutation express immediately
4. Dominant mutation express immediately

Q. A monohybrid cross between heterozygous tall pea plant and homozygous dwarf pea plant produced $F_1$ generation with genotypic ratio G and phenotypic ratio P. Find G and P

1. G = 1:1, P = 1:1
2. G = 3:1, P = 1:2:1
3. G = 1:2:1, P = 3:1
4. G = 2:1, P = 1:1

Q. Short notes on: Mendel's monohybrid cross and dihybrid cross

Q. Why did Mendel select the pea plant for his experiment?

Q. Set of observable characteristics in an organism is called phenotype.

1. True
2. False

Q. Can you explain Law of segregation with an example and justification?

Q.

Mendel’s dihybrid phenotypic ratio is

1. 3:1

2. 1:2:1

3. 1:1

4. 9:3:3:1

Q.

Law of segregation

Q. Which amongst the following dominant character is found in human beings?

1. Brown hair
2. Attached earlobe
3. Straight hair
4. Ability to roll tongue

Q.

How many different phenotypes and genotypes are obtained in Mendel’s $F_2$ generation of dihybrid cross?

1. 4 phenotypes and 9 genotypes

2. 4 phenotypes and 16 genotypes

3. 16 phenotypes and 8 genotypes

4. 2 phenotypes and 16 genotypes

Q. " A trail must be inherited but may not be expressed". Justify.

Q. Which of the following traits were studied by Mendel for his experiments on pea plants?

1. Shape of the pod
2. Position of the flower
3. Shape of the seed
4. Colour of the pod

Q. What is Mendelism? Explain the law of independent assortment.

Q. Why did Mendel choose pea plant for his experiment?

Q. The phenotypic ratio in a dihybrid cross is _________________?

Q. Identify the phenotypic ratio of Filial 2 generation given that, the parents are tall (TT) and dwarf (tt).

1. 1 Tall, 3 Dwarf
2. 4 Tall, 0 Dwarf
3. 3 Tall, 1 Dwarf
4. 2 Tall, 2 Dwarf

Q. Gregor Johann Mendel, the father of genetics was

1. Austrian monk
2. British monk
3. Italian monk
4. German scientist