In plant anatomy, the 'Casparian strip' is a band of cell wall material made of suberin and lignin found in the: MCQ with Answer and Explanation

In plant anatomy, the 'Casparian strip' is a band of cell wall material made of suberin and lignin found in the:
A. Pericycle of the root
B. Cortex of the stem
C. Epidermis of the root
D. Endodermis of the root
Answer: Option D
Solution (By JKSSB Mock Tests)
The Casparian strip is a waterproof band of suberin and lignin found in the radial and transverse cell walls of the endodermis (the innermost layer of the cortex) in plant roots. It acts as a barrier to the passive flow of water and dissolved minerals through the cell walls (the apoplastic pathway). This forces water and solutes to cross the selectively permeable plasma membrane and enter the symplastic pathway, allowing the plant to control and filter what enters the vascular cylinder (stele).

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Practice More Biology Questions

Question #1
Consider the following statements about DNA fingerprinting:
1. It uses VNTRs (variable number tandem repeats).
2. It can be used in paternity testing.
3. It requires amplification by PCR.
Which of the above is/are correct?
A. 1 and 3 only
B. 1 and 2 only
C. 1, 2, and 3
D. 2 and 3 only

Correct Answer: Option C


Explanation:
DNA fingerprinting analyzes VNTRs, often amplified by PCR, and is used in forensics and paternity. All three are correct.

This question belongs to: Science Biology
Question #2
Consider statements about ecology: 1. Primary succession occurs on bare rock. 2. Secondary succession occurs after a forest fire. 3. Climax community is unstable. Which are correct?
A. 1 and 3 only
B. 2 and 3 only
C. 1 and 2 only
D. 1, 2 and 3

Correct Answer: Option C


Explanation:
Primary succession begins on lifeless, barren substrates like bare rock, where no soil exists initially. Secondary succession occurs in areas where an existing community has been destroyed by disturbances like forest fires, floods, or logging, but soil remains. A climax community is the final, stable, and self-perpetuating stage of ecological succession, in equilibrium with the environment. Thus, statements 1 and 2 are correct.

This question belongs to: Science Biology
Question #3
The site of fertilization in the human female reproductive tract is usually the:
A. Cervix
B. Uterus
C. Ampulla of the fallopian tube
D. Ovary

Correct Answer: Option C


Explanation:
Fertilization typically occurs in the ampulla, the widest region of the fallopian tube, where the sperm meets the secondary oocyte. The zygote then travels to the uterus for implantation. The ovary releases the egg, the uterus supports embryo development, the cervix is the lower portion opening into the vagina.

This question belongs to: Science Biology