List of practice Questions

Draw a labelled diagram of the embryonic stage that gets implanted in the human uterus. State the functions of two labelled parts.

Mention the functions of each of the following: (i) Tassels of Corn Cob, (ii) Scutellum

Farmers prefer apomictic seeds over hybrid seeds. Give any two reasons.

Suggest how a virus-free healthy plant can be obtained from a diseased sugarcane plant.

In order to force bacteria to take up the recombinant DNA, they must be made competent. Explain how it can be achieved.

Differentiate between grazing food chain and detritus food chain.

Bt-toxin genes have been expressed in plants in order to provide resistance against:
• [(i)] lepidopterans and fungi
• [(ii)] animals and bacteria
• [(iii)] coleopterans and dipterans
• [(iv)] lepidopterans

According to IUCN, some of the extinctions include:
• [(i)] Dodo
• [(ii)] Indian gazelle
• [(iii)] Thylacine
• [(iv)] Steller’s Sea Cow

Assertion (A): Genetically modified microbes help in crop protection.
Reason (R): Bacillus thuringiensis (Bt) bacteria control insects by producing prototoxins.

Assertion (A): Trichoderma species are free living fungi that are very common in the root ecosystems.
Reason (R): They are effective bio-control agents of several plant pathogens.

Assertion (A): The endometrium undergoes cyclic changes during the menstrual cycle.
Reason (R): Perimetrium contracts strongly during delivery of the baby.

Assertion (A): Repetitive sequences make up a very large portion of human genome.
Reason (R): Repetitive sequences do not have direct coding functions in the genome.

Select the odd option in the context of convergent evolution.

Monascus purpureus is a yeast used commercially in the production of which one of the following?

Given below is the restriction site of a restriction endonuclease Pst I and the cleavage sites on a DNA molecule.

Choose the option that gives the correct resultant fragments.

Which of the following ecosystems is most productive in terms of net primary productivity?

The cells of endosperm have 24 chromosomes. What will be the number of chromosomes in the gametes?

During different phases of menstrual cycle, hormones are secreted. Choose the option showing the correct sequence of hormones.

A DNA molecule is 160 base pairs long. It has 30% Guanine. How many Adenine bases are present in this DNA molecule?

Arrange the following in the correct sequence of their evolution and select the correct option:
• [(i)] Seaweed
• [(ii)] Invertebrates
• [(iii)] Jawless fish

S is the stimulant of central nervous system and interferes with the transport of T, a neurotransmitter. Identify S and T and choose the correct option.

In a human female, menstrual cycle of 28 days is represented by the diagram given below (Phase I: Days 1--5, Phase II: Days 6--13, Phase III: Days 15--28). Select the correct statement related with this diagram.

According to Collision Theory, the rate constant of a chemical reaction depends on activation energy. If the activation energy of a reaction increases, then the value of the rate constant \(k\) will:

The work functions of two metals ($M_A$ and $M_B$) are in the 1 : 2 ratio. When these metals are exposed to photons of energy 6 eV, the kinetic energy of liberated electrons of $M_A$ : $M_B$ is in the ratio of 2.642 : 1. The work functions (in eV) of $M_A$ and $M_B$ are respectively.