Tag: mendel's law of inheritance

Questions Related to mendel's law of inheritance

Which of the following characteristics represent inheritance of dihybrid crosses in pea :
a) Incomplete dominance
b) Dominance
c) Law of segregation 
d) Co - dominance
e) Polygenic inheritance
f) Law of independent assortment 

  1. b and f

  2. a, d and f

  3. b, c and f

  4. b , c and e


Correct Option: A

The main reason for the success of Mendel was that

  1. He made statistical analysis of the offsprings.

  2. He first took only one character at a time in his crosses.

  3. He kept pedigree records.

  4. He selected pea plants.


Correct Option: B
Explanation:

Main reasons for the success of Gregor Mendel: 

1. Mendel concentrated in one or few characters at a time.
2. He made controlled crosses and kept careful numerical records of the results.
3. He suggested 'factors' as a cause of characters.
4. The experimental material Pisum sativum was a wise choice.

Correct reason of Mendel's success was

  1. He repeated each experiment several times.

  2. Traits chosen by him had genes far apart so that linkage was absent.

  3. He kept record of all experiments.

  4. He used statistical techniques.


Correct Option: B
Explanation:

Mendel chose seven pairs of contrasting traits, the gene for each of which is present on seven different chromosomes of pea plant. Due to the presence on different chromosomes, Mendel's trait followed independent assortment during meiosis and produced the expected parental and recombinant phenotypes. If genes of these traits would have present together showing linkage, Mendel would not have got the expected results. Repeating the experiment, keeping records and use of statistical analysis were the secondary factors; major being the chosen traits not showing linkage. 

So, the correct answer is 'Traits chosen by him had genes far apart so that linkage was absent'.

Mendel was lucky, because

  1. He was born in Austria which is a nice country.

  2. He used pea plant for his experiment which is rich in protein.

  3. The genes for different characters are located on different chromosomes in Pisum sativum.

  4. The Pisum sativum is short-lived plant.


Correct Option: C
Explanation:

Mendel was lucky because he used pea plant i.e. Pisum sativum, they are bisexual, they had pure breeding varieties with observable characters, & each character is regulated by one type of gene, whether it is tall, dwarf, round or wrinkled etc. It was an ideal choice for him.

So, the correct answer is "The genes for different characters are located on different chromosomes in Pisum sativum".

Mendel was successful in formulating the laws of inheritance whereas his predecessors were not because

  1. He studied one clear-cut character at a time

  2. The characters studied by him were present on separate chromosomes

  3. Of the right choice of material

  4. He kept accurate records of his experiments


Correct Option: A
Explanation:

Mendel was successful in formulating the laws of inheritance whereas his predecessors were not because of the following reasons.

He selected only pure breeding varieties of pea for his experiments.

He took one or two characters at one time while his predecessor often studied all the traits simultaneously.

He formulated theoretical explanations for interpreting his results.

He used statistical methods and law of probability for analyzing results, etc.,

So, the correct explanation is ‘He studied one clear-cut character at a time’.

Mendel's laws were rediscovered by

  1. Lamarck, de Vries and Correns

  2. Hugo de Vries, Correns and Tschermak

  3. Morgan, Beadle and Tatum

  4. Hugo de Vries, Morgan and Correns


Correct Option: B
Explanation:

Mendel’s work(monohybrid cross & dihybrid cross) did not receive any recognition, remained unnoticed, and unappreciated for several years due to the following reasons:

Communication was not easy in those days and his work could not be widely publicized.

His concept of stable, unblending and discrete units or factors for various traits did not find acceptance from the contemporaries.

His approach of using mathematics and statistical analysis to explain biological phenomena was totally new and unacceptable to many biologists. He could not provide any physical proof for the existence of factors. In 1900, three scientists Hugo de Vries, Carl Correns, and Erich von Tschermark, worked independently on Mendel’s work, proved whatever explained by Mendel on inheritance is true. It is called Rediscovery of Mendel’s laws.

So, the correct answer is 'Hugo de Vries, Correns and Tschermak'.

Correct reason for Mendel's success was

  1. He repeated each experiment several times

  2. Traits chosen by him had genes far apart so that linkage was absent

  3. He kept record of all experiments

  4. He used statistical techniques


Correct Option: B
Explanation:

He chose garden pea that was easy to grow and to hybridise artificailly.

The plant reproduce well and grows to maturity in a single season.

Mendel then chose to follow seven visible features(unit characters), each represented by two contrasting forms or traits.

Mendel was fortunate in choosing a diploid plant because diploid organisms contain only two sets of chromosomes.

A singe alteration in a trait was therefore demonstrated by a visible differences between varieites.

He restricted his examination to one or very few pairs of contrasting traits in each experiment.

He also kept accurate quatitative records, a necessity in genetic experiments.

In his experiments, no appearance of recombinations and linkage.

So, the correct option is ‘Traits chosed by him had genes far apart so that linkage was absent’.

Mendel's work was rediscovered in

  1. 1756

  2. 1865

  3. 1900

  4. 1910


Correct Option: C
Explanation:

Mendel’s work was rediscovered by Hugo de Vries, T.Correns, and Carl Correns independently in 1900.

So, the correct answer is ‘1900’.

When two genes control a single character and have cumulative effect the ratio is _______

  1. $1:1:1:1$

  2. $1:4:6:4:1$

  3. $1:2:1$

  4. $1:6:15:20:15:6:1$


Correct Option: C
Explanation:
When two genes present on the same loci give an additive or cumulative effect like the spotted and Dotted seed of Lens sps the ratio is 1:2:1
So, the correct answer is '1:2:1'

Successive exploitation of heterocyst depends upon the ______________.

  1. Presence of heterotic effect in the hybrid

  2. Availability of male sterility

  3. Out crossing nature of the flower

  4. Heterotic effect and availability


Correct Option: A