Advertisements
Advertisements
प्रश्न
A big tree falls in a forest but its roots are still in contact with the soil.
The branches of this fallen tree grow straight up (vertically). This happens in response to ______.
पर्याय
water and light
water and minerals
gravity and water
light and gravity
उत्तर
A big tree falls in a forest but its roots are still in contact with the soil.
The branches of this fallen tree grow straight up (vertically). This happens in response to light and gravity.
Explanation:
It is because a plant stem grows towards the light in the upward direction against the force of gravity.
APPEARS IN
संबंधित प्रश्न
Design an experiment to demonstrate hydrotropism.
Where is the auxin hormone made in a plant stem?
Define geotropism.
Which of the following are not tropisms?
(i) growing of pollen tube in response to a sugary substance
(ii) folding up of leaves of sensitive plant in response to touch
(iii) winding of tendril around a support in response to touch
(iv) opening up of the leaves of a daisy flower in response to light
(a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (ii) and (iv)
The top part A of the flask-shaped reproductive organ X in the flower of a plant secrets a surgery substance into its lower part B which goes towards the bottom part C of the flask-shaped organ. When a tiny grain D coming from the top part E of another reproductive organ Y i the flower falls on part A, it grows a long tube F through the organ X i response to the sugary substance and reaches the bottom part C of flask-shaped organ to carry out fertilisation.
(a) Name parts (i) organ X, and (ii) organ Y, inside the flower?
(b) Name parts (i) A (ii) B, and (iii) C, of flask-shaped organ.
(c) Name (i) grain D, and (ii) part E of organ Y.
(d) Name the tube F.
(e) What is the phenomenon of growing a long tube in response to sugary substance in the process of fertilisation in a flower known as?
When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk, the petals of a dandelion flower close.
state two ways in which the above two processes differ.
Response of plant roots towards water is called:
A student accidentally places her hand on the flame of the candle and quickly pulls her hand away. The flame represents:
The growth of pollen tubes towards ovules is due to
When the leaves of a sensitive plant are touched with a finger, they fold up, and when the light fades at dusk the petals of a sunflower. These two plants show ______ and ______ movements.
