NCERT Solutions for Control And Coordination of Page 108

Q1: What are plant hormones?

Answer:

Plant hormones are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all the growth and development activities like cell division, enlargement, flowering, seed formation, dormancy, and abscission.

Q2: How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?

Answer:

The movement of the sensitive plant’s leaves is touch-sensitive and independent of growth, which is known as Thigmotropism. The growth-related tendency of the shoot toward light is known as Phototropism.

Q3: Give an example of a plant hormone that promotes growth.

Answer:

Auxin is an example of a plant hormone that promotes and regulates the growth of the plant.

Q4: How do auxins promote the growth of a tendril around a support?

Answer:

When a tendril is in contact with the support of a wall or any other plant, more auxin diffuses towards the side of the tendril away from the support. This auxin concentration stimulates the cells to grow longer on the tendril side which is far from the support.

Q5: Design an experiment to demonstrate hydrotropism.

Answer:

Hydrotropism is the process of growth or movement of roots toward the source of water. Here is an experiment that is performed to observe the growth of plants when water is present.

Procedure: 

• Let’s take two beakers A and B.
• In beaker A, let’s add some moist soil and sow the seeds.
• In beaker B, add dry soil in one part and moist soil in another part and sow the seeds. Also, place a small beaker of water just adjacent to it.
• Keep it for some time so that the plants can grow.

Result:

It was found that in beaker A due to the presence of moist soil, plants have grown normally and roots were straight.
In beaker B, it was observed that because of, the presence of the water beaker next to it plants have grown towards the water, as shown in the below figure.

Conclusion: 

This experiment states that the plants move and grow towards the source of water, hence plants show hydrotropism.

Control and Coordination is about control mechanisms and movement in organisms. This article includes free NCERT Solutions for Class 10 Science Chapter 7 Control And Coordination, developed by the top Biology experts at GFG, according to the latest CBSE Syllabus 2023-24 and guidelines.

These NCERT Solutions for Class 10 Science Chapter 7 Control And Coordination have covered all important topics to help students in their board exams, as well as in preparing for future competitive exams.