NEET Practice Questions

Q21. What does a right shift in the oxygen dissociation curve of hemoglobin indicate about the physiological conditions?

Decreased oxygen affinity, indicating conditions such as a lower pH, a higher temperature, or increased levels of CO₂.
Increased oxygen affinity, indicating conditions such as a higher pH, a lower temperature, or decreased levels of CO₂.
Decreased temperature and CO₂ levels, leading to a reduced ability of hemoglobin to release oxygen to tissues.
Increased hemoglobin saturation with oxygen at lower partial pressures, indicating hyperventilation.

Q22. Which statement correctly describes the impact of temperature on enzyme activity?

Enzyme activity decreases indefinitely as temperature increases due to increased kinetic energy of the substrates.
Enzyme activity increases until an optimum temperature is reached, beyond which activity declines rapidly due to denaturation.
Enzyme activity is independent of temperature changes within the living organism’s permissible range.
High temperatures always increase enzyme stability and, therefore, enhance enzyme activity.

Q23. Which of the following techniques is used to introduce recombinant DNA into bacterial cells?

Polymerase Chain Reaction (PCR)
Southern blotting
Gel electrophoresis
Transformation

Q24. Consider the given two statements:

Assertion (A):	Bt cotton plants are resistant to insect pests like the bollworm.
Reason (R):	The Bt toxin produced in these plants is harmless to mammals and to bacillus itself.

Choose the correct option.

Both(A)and(R)are True and(R)is the correct explanation of(A).
Both(A)and(R)are True but(R)is not the correct explanation of(A).
(A)is True but(R)is False.
(A)is False but(R)is True.

Q25. Given below are two statements:

Assertion (A):	Magnetic dipoles, when placed near a long straight current-carrying wire, are deflected perpendicular to the wire.
Reason (R):	The magnetic field lines of a straight current-carrying wire are oriented in a direction which is perpendicular to the wire.

Both(A)and(R)are True and(R)is the correct explanation of(A).
Both(A)and(R)are True but(R)is not the correct explanation of(A).
(A)is True but(R)is False.
(A)is False but(R)is True.

Q26. Which meristem is responsible for the regeneration of parts of grasses removed by the grazing herbivores?

Apical meristem
Intercalary meristem
Interfascicular cambium
Fascicular vascular cambium

Q27. Regarding the regions of the root tip:

I.	Root cap protects the tender apex of the root
II.	Region of elongation is proximal to region of meristematic activity
III.	Region of maturation has root hairs

Only I and II are correct
Only I and III are correct
Only II and III are correct
I, II and III are correct

Q28. Which phase of the prophase I of meiosis I is recognized by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other except at the sites of crossovers?

Zygotene
Pachytene
iplotene
iakinesis

Q29. How many of the given genetic disorders are due to mutations in autosomal genes?
I: Sickle cell anaemia
II: Thalassemia
III: Phenylketonuria
IV: Haemophilia

Q30. Consider the given two statements:

Assertion (A):	It is desirable that restriction enzymes that create sticky ends in resultant fragments are used to create rDNA.
Reason (R):	Creation of sticky ends facilitates the function of DNA polymerase.

Both(A)and(R)are True and(R)correctly explains(A)
Both(A)and(R)are True but(R)does not correctly explain(A)
(A)is True,(R)is False
(A)is False,(R)is True

« 1 2 3 4 5 … 25 »