List of practice Questions

Read the following passage and answer the questions that follow.
According to evolutionary theory, every evolutionary change involves the substitution of a new gene for the old one and the new allele arises from the old one. Continuous accumulation of changes in the DNA coding for proteins leads to evolutionary differences. The chemical composition of DNA is basically the same in all living beings, except for differences in the sequence of nitrogenous bases. Given below are percentage relative similarities between human DNA and DNA of other vertebrates:

Assertion (A) : Isolated single cells can be fused to produce somatic hybrids.
Reason (R) : Cells selected for somatic hybridisation have desirable characters.

Assertion (A) : An antibody is a protein molecule made by the lymphocytes.
Reason (R) : An antibody binds to a specific foreign antigen and neutralizes its odd effects.

Assertion (A) : Male contraceptive ‘Nirodh’ works on the principle of avoiding chances of ovum and sperm meeting.
Reason (R) : It is made of thin rubber/latex sheath and is used to cover the penis before coitus.

In a translational unit UTRs are present at :

Land reptiles which went back into water about 200 mya to evolve into fish-like reptiles were :

If the sequence of bases in DNA is ATTCGATG, then the sequence of bases in the transcript will be :

A normal couple produces half the sons as haemophilic and half the daughters as carriers. Choose the option that correctly indicates the chromosome on which the gene for this trait is located.

The lymphoid organ located within the lining of respiratory, digestive and urogenital tract is :

Given below are a few statements with reference to the human sperm.
1. Sperm head contains a large nucleus and a lot of cytoplasm.
2. Mitochondria in the middle piece of a sperm provides ATP for the sperm motility.
3. Posterior part of the sperm head is covered by acrosome.
4. Spermatids undergo maturation into spermatozoa by the process of spermiogenesis.
5. Acrosomal secretions help in the entry of the sperm into the ovum at the time of fertilization.
Choose the option with all true statements from the given options :

Certain viruses used as biological control agents belong to the genus :

How is triple fusion achieved in these plants ?

Cistron is a segment of DNA coding for a :

Select the statements that are true for a typical monocotyledonous embryo from the given options.
1. Scutellum is present towards the centre of the embryonal axis.
2. Embryonal axis of the lower end has radicle and root cap covered by coleoptile.
3. The portion of embryonal axis above the level of attachment of scutellum is epicotyl.
4. Shoot apex and few leaf primordia of embryo are enclosed in a hollow foliar structure.
Choose the correct answer from the following :

Explain the structure of a mature embryo sac of a typical flowering plant.

Describe the changes in the ovary and the uterus as induced by the changes in the level of pituitary and ovarian hormones during menstrual cycle in a human female.

If a natural population with 200 individuals is in Hardy-Weinberg equilibrium for a gene with two alleles A and a, and with the gene frequency of allele A of 0.8, the genotype frequency of Aa will be :

In a pedigree chart, if two unaffected individuals have a child with the trait, what is the most likely mode of inheritance for this trait ?

Explain how human pro-insulin is processed in the cell to become a fully mature functional insulin.

Describe how human insulin is produced using the techniques of genetic engineering.

Describe what is meant by downstream processing.

Describe the Species-Area relationship as observed by Alexander von Humboldt, for a wide variety of taxa in nature.

State any two criteria for determining biodiversity hotspots.