Problem 70 - Objective Biology for NEET

Question

The best example of imbibition is (a) Absorption of water by seed (b) Absorption of water by dry wood (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

The correct answer is (c) Both (a) and (b).

Step 1: Understand imbibition

Imbibition is the process where water is absorbed by solids (colloids) which leads them to increase in volume. It is a type of diffusion which goes on until equilibrium is reached. This process is extremely important in plant life.

Step 2: Apply the knowledge

Both absorption of water by seed and dry wood are examples of imbibition. In seed, the absorption of water causes it to swell and begins the germination process. Similarly, imbibition causes dry wood to swell when it absorbs water.

Step 3: Choose the correct answer

Since both options (a) and (b) are accurate representations of the imbibition process, the correct answer should be (c) Both (a) and (b).

Key Concepts

Water Absorption

Water absorption is a crucial process for both seeds and plants. At its core, it involves the intake of water by solids, which are often porous materials or powdered substances that have the ability to absorb moisture.

• Imbibition is a perfect example of water absorption, where materials swell due to water uptake.
• This process is not passive; it requires energy to overcome the tension between the molecules within the material and the water.
• Seeds absorb water primarily through imbibition, which is the initial phase of water uptake and is vital for their activation and subsequent growth.

When seeds absorb water, they begin to rehydrate, activating important biochemical processes. Without water absorption, seeds remain dormant and unable to germinate.

Seed Germination

Seed germination is a fascinating process that transforms a dormant seed into a growing plant. It is initiated when a seed absorbs water, kick-starting its internal mechanisms.

• Water uptake leads to the swelling and softening of the seed coat.
• This stimulates the seed’s metabolism, activating enzymes that convert stored food reserves into usable energy for growth.
• As the seed metabolizes effectively, critical structures such as radicles (the first root) and plumules (the first shoot) emerge.

Moreover, environmental factors such as temperature and oxygen play significant roles. A balance of these elements assures that germination proceeds efficiently, ensuring healthy plant growth.

Plant Physiology

Plant physiology refers to the study of essential processes that enable plant growth and development. Understanding these processes is vital, as it explains how plants live and respond to their environment.

• The absorption of water by roots through imbibition contributes to turgor pressure, which helps in maintaining plant structure.
• This water uptake fuels photosynthesis, as water serves as an electron donor in the light-dependent reactions of photosynthesis.
• Another key aspect of plant physiology is the regulation of water loss through transpiration. This involves the movement of water from the roots, through the plant, and out into the atmosphere via stomata.

These physiological processes ensure that plants can survive and adapt, playing a critical role in the ecosystem by facilitating energy flow and nutrient cycles.