অক্সিন আবিষ্কারের ইতিহাস
1. The concept of a growth-promoting substance in plants was first proposed by —
2. In Darwin’s experiment, when the coleoptile tip was removed, the plant —
3. The experiment proving that the growth substance is diffusible was performed by —
4. Who demonstrated unequal distribution of auxin causes curvature?
5. Auxin was first isolated and named by —
6. Went’s experiment involved —
7. Which sequence is correct for auxin discovery?
8. The signal for phototropism moves from —
Choose the correct option:
A. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are true, but Reason is NOT the correct explanation of Assertion.
C. Assertion is true, but Reason is false.
D. Assertion is false, but Reason is true.
9.
Assertion (A): In Paal’s experiment, the coleoptile bends even in darkness.
Reason (R):Unequal distribution of auxin causes unequal growth on two sides.
10.
Assertion (A): Removal of coleoptile tip prevents phototropic curvature.
Reason (R):Auxin is synthesized in the coleoptile tip.
11.
Assertion (A): Boysen-Jensen proved that auxin is a diffusible substance.
Reason (R):Mica sheet allows movement of auxin.
12.
Assertion (A): Frits Went used agar blocks in his experiment.
Reason (R):Agar can absorb auxin from coleoptile tips.
13.
Assertion (A): In phototropism, the illuminated side contains more auxin.
Reason (R):Auxin migrates to the shaded side of the shoot.
14.
Assertion (A): In Paal’s experiment, the coleoptile bends even in darkness.
Reason (R):Unequal distribution of auxin causes unequal growth on two sides.
15.
Assertion (A): Auxin promotes cell elongation in shoots.
Reason (R):Higher auxin concentration on one side causes bending.
16.
Assertion (A): Charles Darwin concluded that the coleoptile tip perceives light.
Reason (R):Covering the tip with an opaque cap prevents bending.
17.
Assertion (A): Paal’s experiment proved that light is essential for curvature.
Reason (R):Auxin redistribution can occur in darkness.
18.
Assertion (A): In Went’s experiment, asymmetric placement of agar block causes curvature.
Reason (R):Agar block releases auxin unevenly into the coleoptile.
19.
Assertion (A): Auxin moves from the apex toward the base in shoots.
Reason (R):This movement is called basipetal transport.
