Zoology MCQs for NEET — Practice Questions with Answers

The text states: 'Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further secretion of oxytocin. The stimulatory reflex between the uterine contraction and oxytocin secretion continues...'

The text mentions: 'Mammary glands differentiate during pregnancy' and 'The mammary glands of the female undergo differentiation during pregnancy'.

The text specifies: 'Soon after the infant is delivered, the placenta is also expelled out of the uterus.'

The context explains: 'Breast-feeding during the initial period of infant growth is recommended by doctors for bringing up a healthy baby' specifically because colostrum 'contains several antibodies absolutely essential to develop resistance for the new-born babies.'

The text states: 'which induce mild uterine contractions called foetal ejection reflex. This triggers release of oxytocin from the maternal pituitary.'

The context clearly states, 'Figure 9.6 Polymerase chain reaction (PCR) : Each cycle has three steps: (i) Denaturation; (ii) Primer annealing; and (iii) Extension of primers'. Therefore, the correct sequence is Denaturation, Annealing, Extension.

The excerpt states, 'multiple copies of the gene (or DNA) of interest is synthesised in vitro'. 'In vitro' means 'in glass' or in a test tube, distinguishing it from processes occurring 'in vivo' (within a living organism).

The text explicitly states under the heading '9.3.3 Amplification of Gene of Interest using PCR': 'In this reaction, multiple copies of the gene (or DNA) of interest is synthesised in vitro'. This is the primary purpose.

The text states, 'PCR is now routinely used to detect HIV in suspected AIDS patients'. It also mentions detecting mutations in suspected cancer patients and other genetic disorders.

The text explains, 'However, very low concentration of a bacteria or virus... can be detected by amplification of their nucleic acid by PCR.' This ability to amplify even minute amounts of genetic material makes early detection possible.