From the given situations, identify 'Chemotropic' and 'Geotropic' movements in parts of plants, respectively:
(i) Growth of pollen tube towards ovule.
(ii) Movement of sunflower towards sunlight.
(iii) Movement of root towards Earth/Gravity.
(iv) Movement of leaves due to breeze.
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Tropic movements in plants:
Chemotropism \(\Rightarrow\) Chemical stimulus (e.g., pollen tube growth)
Chemotropism: Growth or movement of a plant part in response to a chemical stimulus.
Geotropism (Gravitropism): Growth or movement of a plant part in response to gravity.
Phototropism: Growth or movement in response to light.
Thigmotropism: Growth or movement in response to touch or contact.
Step 2: Analyze each given situation.
(i) Growth of pollen tube towards ovule: This is Chemotropism because the pollen tube grows in response to chemical signals (sugars, calcium) released by the ovule.
(ii) Movement of sunflower towards sunlight: This is Phototropism (response to light), not chemotropism or geotropism.
(iii) Movement of root towards Earth/Gravity: This is Geotropism (positive geotropism as roots grow downward in response to gravity).
(iv) Movement of leaves due to breeze: This is a physical movement (hygroscopic or mechanical), not a tropic movement. It is not a growth movement.
Step 3: Identify chemotropic and geotropic movements.
Chemotropic movement: (i) Growth of pollen tube towards ovule
Geotropic movement: (iii) Movement of root towards Earth/Gravity
Step 4: Match with options.
Option (A) says (i) and (iii) respectively, which correctly identifies chemotropic and geotropic movements in that order.
Final Answer: (A) (i) and (iii) respectively
