NEET Biology 5

Question 1

Which part of the brain is primarily responsible for regulating body temperature, hunger, and thirst?

Accepted Answer

Hypothalamus

Answer

The hypothalamus acts as the master regulator of homeostasis, controlling temperature, hunger, thirst, and circadian rhythms.

Question 2

In which type of RNA secondary structure do complementary base sequences within the same strand pair to form a stem-loop?

Accepted Answer

Hairpin loop

Answer

A hairpin loop (stem-loop) forms when complementary sequences within a single RNA strand fold back and base-pair with each other.

Question 3

Which of the following conditions is caused by trisomy of chromosome 21?

Accepted Answer

Down syndrome

Answer

Down syndrome (trisomy 21) results from three copies of chromosome 21 and is the most common autosomal trisomy.

Question 4

The enzyme telomerase adds telomeric sequences using which mechanism?

Accepted Answer

Uses its own RNA component as template

Answer

Telomerase is a reverse transcriptase that uses its internal RNA subunit as a template to extend telomeric DNA repeats.

Question 5

Which of the following best describes the role of auxin in phototropism?

Accepted Answer

Auxin migrates to the shaded side, promoting cell elongation

Answer

In phototropism, auxin moves laterally to the shaded side of the shoot tip, causing greater elongation and bending toward light.

NEET - National Eligibility cum Entrance Test Practice Test