Question

Classify each of the following items below on the left as either pertaining to Mendelian genetics (described by Mendel) or non-Mendelian genetics (discovered after Mendel) using the dropdowns on the right.

1. Dominant-recessive allele system

A. Mendelian           

B. Non-Mendelian      

2. Monohybrid cross yields a phenotypic ratio of 3:1

A. Mendelian           

B. Non-Mendelian      

3. ABO blood type system

A. Mendelian           

B. Non-Mendelian      

4. A male frog with a split vocal sac (Ss) and green eyes (GG) mates with a single sac female (ss) with green eyes (Gg) to make a tadpole with s single sac and green eyes.

A. Mendelian           

B. Non-Mendelian      

5. Codominant alleles

A. Mendelian           

B. Non-Mendelian      

6. X-linked recessive diseases

A. Mendelian           

B. Non-Mendelian      

  

Answer 1

Answer-1 (A) Mendelian

Explanation-

Gregor Johann Mendel also known as the Father of Modern Genetics. His contribution to genetics by experiments conducted on Pisum sativum is remarkable. Based on the results of experiment he presented three laws namely Law of Dominance, Law of Segregation and Law of Independent Assortment.

According to the Law of Dominance, in a heterozygous condition only the character of one allele is expressed over the other in the F1 generation. And this is known as the dominant character or dominant allele. The recessive allele is expressed during the F2 generation.

Answer-2 (A) Mendelian

Explanation-

During a monohybrid cross i.e. the cross conducted between two contrasting characters the phenotypic ratio is 3:1. The cross is given below-

Answer-3 (B) Non- mendelian

Explanation-

Co- dominance is when both the alleles are completely expressed in a heterozygous offspring. As such the ABO blood grouping is an example of co-dominance. ABO blood groups are controlled by the gene I which has three allele i.e. I_A, I_B and i. When both I_A and I_B are present together this is known as co-dominance.

Answer- 4 (A) Mendelian

Explanation-

It is based on the Law of Independent Assortment which was given by Mendel. It states that, when two pair of traits are crossed, tge segregation of one pair of characters is independent of the other pair of character. This means that they are incompletely assorted. As a result the phenotypic ratio is 9:3:3:1. Thus, the cross is as follows-