Which one of the following is caused due to point mutation?

Amniocentesis should not be used for:

The reasons why not both the strands of DNA are copied during transcription are:
(A) Replication fork will not be formed
(B) The two RNA molecules synthesised will form dsRNA molecule
(C) Complicate the genetic information transfer machinery
(D) dsRNA molecule will not be translated into proteins
Choose the correct answer from the options given below:

In plants, continued self pollination results in

Read the following paragraph and answer the given questions:
DRUGS AND ALCOHOL ABUSE
The drugs, commonly abused are opioids, cannabinoids, and coca alkaloids. Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa. The flower tops, leaves and the resin of cannabis plant are used in various combinations to produce marijuana, hashish, charas and ganja. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body. It interferes with the transport of the neuro-transmitter dopamine. Cocaine, commonly called coke or crack is usually snorted. It has a potent stimulating action on central nervous system, producing a sense of euphoria and increased energy. Excessive dosage of cocaine causes hallucinations. Other well-known plants with hallucinogenic properties are Atropa belladona and Datura. These days cannabinoids are also being abused by some sportspersons. Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused. Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery. Several plants, fruits and seeds having hallucinogenic properties have been used for hundreds of years in folk-medicine, religious ceremonies and rituals all over the globe.
'Coca alkaloids' are obtained from the plant-

Lippes loop is a ________ IUD.

Identify the statements which are correct with respect to fertilization.
(A) Sperm comes in contact with zona pellucida layer of the ovum
(B) Acrosome secretions help the sperm to pass through the cells of corona radiata
(C) Entry of sperm into the cytoplasm of ovum induces the completion of the meiotic division of the secondary oocyte
(D) Fertilization can occur if the ovum and sperms are transported simultaneously to the ampullary region
Choose the correct answer from the options given below:

The composition of Chromate ore is :

Inactive protoxins is converted into its active toxin by:

Two thin lenses of focal lengths \( f_1 \) and \( f_2 \) are in contact and coaxial. The power of the combination is:

Read the following passage carefully and answer the given questions.
Immune System in the Body
The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. The primary lymphoid organs are bone marrow and thymus where immature lymphocytes differentiate into antigen-sensitive lymphocytes. After maturation the lymphocytes migrate to secondary lymphoid organs like spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix. The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells. The bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced. Each antibody molecule has four peptide chains, two small called light chains and two longer called heavy chains. Hence, an antibody is represented as H2L2. Different types of antibodies are produced in our body. IgA, IgM, IgE, IgG are some of them. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs.
Human immune system recognizes the viral proteins as:

The rate of change of the area of an equilateral triangle with respect to its side when its side \(=2\) is :

To increase the current sensitivity of a moving coil galvanometer by 50%, its resistance is increased so that the new resistance becomes twice its initial resistance. By what percentage does its voltage sensitivity change?