NEET UG 2003 — Principles of Inheritance and Variation

In Drosophila, the sex is determined by,

Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes arc reversed in one cross, is known as:

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

Christmas disease is another name for

Down's syndrome is caused by an extra copy of chromosome number 21. What percentage of offspring produced by an affected mother and a normal father would be affected by this disorder?

Which one of the following traits of garden pea studied by Mendel was a recessive feature?

Which one of the following discoveries resulted in a Nobel Prize?

What would happen if in a gene encoding a polypeptide of 50 amino acids, $25^{\text {th }}$ codon (UAU) is mutated to UAA?

Genes for cytoplasmic male sterility in plants are generally located in:

Pattern baldness, moustaches and beard in human males are examples of:

The linkage map of $\mathrm{X}$-chromosome of fruitfly has 66 units, with yellow body gene $(y)$ at one end and bobbed hair $(B)$ gene at the other end. The recombination frequency between these two genes $(y$ and $b$ ) should be:

Nicotiana sylvestris flowers only during long days and N.tabacum flowers only during short days. If raised in the laboratory under different photoperiods, they can be indued to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason considering $N$. sylvestris and N.tabocum to be separate species ?

When a cluster of genes show linkage behaviour they:

Which one of the following conditions though harmful in itself, is also potential saviour from a mosquito borne infectious disease?