Q1. The seminiferous tubules open into which of the following structures before entering the epididymis?
Vas deferens
Ejaculatory duct
Rete testis
Seminal vesicle
Explanation:
Q2. Ethylene exhibits its characteristic triple response in seedlings, which includes:
Inhibition of stem elongation, thickening of the stem, and horizontal growth.
Increased leaf expansion, root elongation, and faster seed germination.
Acceleration of flowering, increased transpiration, and decreased chlorophyll content.
Suppression of fruit ripening, promotion of seed dormancy, and increased stomatal closure.
Explanation:
Q3. What is the term used to describe the vertical distribution of different species occupying various levels in an ecosystem?
Zonation
Species composition
Biotic interaction
Stratification
Explanation:
Q4. Which layer of blood vessels is comparatively thin in veins but thick in arteries?
Tunica externa
Tunica media
Tunica intima
Endothelium
Explanation:
Q5. Consider the given two statements:
Assertion (A):
Hypothyroidism during pregnancy may result in stunted growth and mental retardation in the developing fetus.
Reason (R):
Thyroid hormones are essential for normal development and maturation of the brain in the fetus.
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.
Explanation:
Q6. Consider the given two statements:
Assertion (A):
Secondary growth in dicot stems and roots results in an increase in girth.
Reason (R):
The activity of the vascular cambium and cork cambium contributes to the formation of secondary tissues.
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 but(R)is False.
Both(A)and(R)are False.
Explanation:
Q7. The midbrain, located between the thalamus/hypothalamus of the forebrain and pons of the hindbrain, contains a canal that passes through it called the:
Cerebral aqueduct
Corpus callosum
Central canal
Fourth ventricle
Explanation:
Q8. The small but critical region of the brain that controls various functions, including temperature regulation, thirst, hunger, and is involved in regulation of endocrine functions, is:
Medulla oblongata
Pons
Midbrain
Hypothalamus
Explanation:
Q9. A light string, attached to the ceiling (see figure), passes over a smooth, light pulley and holds a \(2~\text{kg}\)-block. A force \(F,\) acting at an angle \(\theta\) with the horizontal, has to be applied to the pulley to hold it in place. Take \(g=10~\text{m/s}^2.\)
The angle \(\theta\) equals:
\\(30^\\circ\\)
\\(60^\\circ\\)
\\(90^\\circ\\)
\\(45^\\circ\\)
Explanation:
Hint:\(T = mg\)
Step: Find the value of angle \(\theta\).
The force and the tension in the string are shown in the figure below;
From the above figure, by using the property of a linear pair we get; \(60^{\circ}+ 90^{\circ}+\theta^{\circ} = 180^{\circ} \) \(\Rightarrow \theta^{\circ} = 180^{\circ} – 60^{\circ}- 90^{\circ}\) \(\Rightarrow \theta^{\circ} = 30^{\circ} \)
Therefore, the value of angle \(\theta\) is \(30^{\circ}\).
Hence, option (1) is the correct answer.
Q10. Water has an indirect effect on photosynthesis. Which of the following would be true?
Water stress increases the rate of photosynthesis by opening stomata.
Water stress has no effect on photosynthesis.
Water stress decreases the rate of photosynthesis by closing stomata.
Water stress changes the colour of light absorbed by pigments.
