CSIR NET 2024 | Life Science: Inheritance Biology | 10 April

An experiment was conducted in E. coli to map the following genes (pro, his, bio, met, phe and trp) on a circular map using three different Hfr strains:

* Strain 1, order of transfer (early to late) : trp met his pro

* Strain 2, order of transfer (early to late) : his met trp bio

* Strain 3. order of transfer (early to ,late) : pro phe bio trp

Based on the results, what is the most likely map?

The a₁, a₂, and a₃ are three alleles of a gene in Neurospora.
 
Crosses between different mutants gave the following results. Consider the following processes:
A) gene conversion
B) forward mutation
C) non-homologous recombination
D) incomplete dominance

The process which best explains this result is

Mendelism is also known as Mendelian inheritance refers to the principles of heredity formulated by Gregor Mendel. Following are some of the statements made regarding Mendelism.

A) Incomplete dominance, the phenomenon in which the phenotype of the F1 heterozygote is a blend of both dominant and recessive characters of the true-breeding parents is the first law of Mendelian inheritance.

B) The law of independent assortment states that two members of a pair of alleles separate during the process of gamete formation.

C) According to the law of dominance, in a heterozygote, one allele will conceal another allele. Only the dominant allele will contribute to the phenotype of the heterozygote.

D) Mitochondrial inheritance is a non-mendelian inheritance and does not obey the Mendelian laws.

Which of the above statements is/are incorrect?

The spherical seed character (SS) is entirely dominant over the dented seed (ss) character in Mendel's studies. What phenotypes would emerge from crossing a spherical-seeded, short (SStt) plant with a dented-seeded, tall (ssTT) plant if the height characteristics were incompletely dominant, such that TT are tall, Tt are average, and tt are short?

The feather pattern of mallard ducks is determined by multiple alleles at a locus. One allele, M, produces the wild-type mallard pattern. A second allele, M^R, produces a different pattern called restricted, and a third allele, m^d, produces a pattern termed dusky. In this allelic series, restricted is dominant over mallard and dusky, and mallard is dominant over dusky: M^R >M > m^d. Estimate the number of genotypes and phenotypes produced?