List of top Biology Questions

Mention any two ways by which HIV and Hepatitis-B can be transmitted to a healthy person.

Study the graph given below that represents the changes in the thickening of the uterine wall in women ‘X’ and women ‘Y’ over a period of one month: \textit{(Refer to the provided graph.)}
What does the graph with respect to woman ‘X’ and woman ‘Y’ indicate? Give a suitable reason.

Explain the improvement in the quality of the milk produced by it.

Name the first developed transgenic cow.

Assertion (A): Patents are granted by the government to an inventor.
Reason (R): Patents prevent others from commercial use of an invention.

Assertion (A): Some aquatic ecosystems have inverted biomass pyramids.
Reason (R): More energy is required by the organisms occupying higher trophic levels.

Assertion (A): A given fig species can be pollinated only by its partner wasp.
Reason (R): The wasp pollinates the fig inflorescence while searching for suitable egg-laying sites.

Assertion (A): Plasmids are autonomously replicating circular extra-chromosomal DNA.
Reason (R): Plasmids are usually present in eukaryotic cells.

The ‘molecular scissors’ fall in the category of:

ELISA technique is based on the principle of:

Turner’s syndrome in humans occurs due to:

The commonly used vector for human genome sequencing was/were:

Select the option that gives the correct identification of ovum, morula, and blastocyst in a human female reproduction system as shown in the following diagram: \textit{(Refer to the provided diagram.)}

Study the table given below: \begin{center} \begin{tabular}{|c|l|l|} \hline Contraceptive & Mode of Action
\hline A. The pill & I. Prevent sperm reaching cervix
B. Condom & II. Prevent implantation
C. Vasectomy & III. Inhibits ovulation
D. Copper-T & IV. Semen contains no sperm
\hline \end{tabular} \end{center} Select the option where contraceptive/contraceptive method are correctly matched with their mode of action:

A list of organisms is given in column ‘R’, whereas in column ‘S’ a list of products produced by them: \begin{center} \begin{tabular}{|c|c|} \hline Column ‘R’ (Organisms) & Column ‘S’ (Products)
\hline \textit{Lactobacillus} & Cheese
\hline \textit{Saccharomyces cerevisiae} & Curd
\hline \textit{Aspergillus niger} & Citric acid
\hline \textit{Acetobacter aceti} & Acetic acid
\hline \end{tabular} \end{center} Select the option where the organisms are correctly matched with the product:

Hugo de Vries proposed the mutation theory of organic evolution after his experiments on:

Which of the options has correct identification of ‘P’, ‘Q’, and ‘R’ in the illustration of ‘Central Dogma’ given below?

Identify the category of genetic disorder depicted in the pedigree chart given below:

Study the following diagram of Transverse Section of a young anther of an angiosperm:
\textit{(Refer to the provided diagram)}
Select the option where parts ‘A’, ‘B’, and ‘C’ are correctly identified.

In a fertilized ovule of an angiosperm, the cells in which \(n\), \(2n\), and \(3n\) conditions respectively occur are:

Menstrual phase

Luteal phase/secretory phase

Explain the ovarian and uterine events taking place along with the role of pituitary and ovarian hormones, during menstrual cycle in a normal human female under the following phases:
Follicular phase/proliferative phase

Why do plants discourage self-pollination? State any one reason.

Explain any four devices that flowering plants have developed to encourage cross-pollination.