NEET Practice Questions (MCQs) with Answers & Solutions

The summary mentions: 'Counselling and creating awareness among people about reproductive organs, adolescence and associated changes, safe and hygienic sexual practices, sexually transmitted infections (STIs) including AIDS, etc., is the primary step towards reproductive health.'

The text states: 'Medical termination of pregnancy is legalised in our country. MTP is generally performed to get rid of unwanted pregnancy due to rapes, casual relationship, etc., as also in cases when the continuation of pregnancy could be harmful or even fatal to either the mother, or the foetus or both.'

The text defines: 'Infections or diseases transmitted through sexual intercourse are called Sexually Transmitted Diseases (STIs).'

The summary for 'HUMAN REPRODUCTION' explicitly states: 'Humans are sexually reproducing and viviparous.'

The text states: 'The reproductive events in humans include formation of gametes (gametogenesis), i.e., sperms in males and ovum in females, transfer of sperms into the female genital tract (insemination)...'

The text describes the sequence of events as: '...fusion of male and female gametes (fertilisation) leading to formation of zygote. This is followed by formation and development of blastocyst and its attachment to the uterine wall (implantation)...'

The heat shock and chilling method aims to make bacterial cells competent to take up DNA from their surroundings, rather than directly injecting or bombarding the DNA. The NCERT states, 'Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 42°C (heat shock), and then putting them back on ice. This enables the bacteria to take up the recombinant DNA.'

The NCERT text explicitly states, 'Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 42°C (heat shock), and then putting them back on ice. This enables the bacteria to take up the recombinant DNA.' This protocol renders the cells competent.

The context clearly states, 'Most likely, this piece of DNA would not be able to multiply itself in the progeny cells of the organism. But, when it gets integrated into the genome of the recipient, it may multiply and be inherited along with the host DNA. This is because the alien piece of DNA has become part of a chromosome, which has the ability to replicate. In a chromosome there is a specific DNA sequence called the origin of replication, which is responsible for initiating replication.'

The NCERT states, 'Agrobacterium tumifaciens, a pathogen of several dicot plants is able to deliver a piece of DNA known as ‘T-DNA’ to transform normal plant cells into a tumor and direct these tumor cells to produce the chemicals required by the pathogen.'