Chapter 1 Nutrition in Plants

(b)

It shows different type of nutrition which is called symbiosis.

(b)

More bubbles will be observed in B in 10 min. because rate of photosynthesis increases in presence of sunlight and rate of photosynthesis amount of O₂.

(d)

Plants are the autotrophs that can prepare food for themselves by using CO₂, H₂O and minerals in the presence of sunlight. Nitrogen is not required for photosynthesis.

(c)

During photosynthesis, chlorophyll containing cells of leaves in the presence of sunlight, use carbon dioxide and water to synthesis carbohydrates. The process can be represented as an equation:

Carbon dioxide + Water Carbohydrate + Oxygen.

Presence of starch, a carbohydrate in the leaves is regarded as an evidence of photosynthesis.

(a)

Small pores are present on the lower surface of leaf. These pores performs the function of exchange of gases i.e. CO₂enters the leaf and oxygen go out of the leaf. These pores are also control the rate of transpiration.

(c)

Insectivorous plants, in fact, are green plants which prepare their own food from the raw material (carbon dioxide, water and sunlight) obtained from the soil and atmosphere, just like the autotrophs. The nitrogen requirement of these plants is provided by the insects which these plants capture.

(b)

Some organisms live together and share shelter and nutrients. This is called symbiotic relationship. For example, certain fungi live in the roots of trees. The tree provides nutrients to the fungus and, in return, receives help from it to take up water and nutrients from the soil. This association is very important for the tree.

(c)

Saprophytic mode of nutrition is found in mushrooms. In this mode of nutrition plant feeds on dead and decaying organic matter. The mode of nutrition of other three are given below.

Bladderwort Insectivorous mode of nutrition

Lichens Symbiotic mode of nutrition

Cuscuta Parasitic mode of nutrition

(a)

These plants lack green colour. They feed on digestive juices from the dead and decaying organic matter.

(a)

The leaves have a green pigments called chlorophyll. It helps leaves to capture the energy of the sunlight. This energy is used to synthesise food from carbon dioxide and water.

(c)

Besides leaves, photosynthesis also takes place in other green parts of the plant in green stems and green branches. The desert plants have scale- or spine-like leaves to reduce loss of water by transpiration. These plants have green stems which carry out photosynthesis.

(d)

The leaves other than green also have chlorophyll. The large amount of red, brown and other pigments mask the green colour. Hence, photosynthesis also takes place in these leaves.

(a)

In a lichen, algal and fungal partners live together and both are mutually beneficial. Algal, a chlorophyll containing component of a lichen is autotropic. It provides food material to the fungal component in the lichen. In return, the fungus (heterotroph) provides shelter, water and minerals to the alga.

(d)

Rhizobium do not feed on atmospheric nitrogen. It cannot make its own food. So it lives in the roots of gram, peas, moong beans and other legumes and provide them nitrogen. In return, the plants provide food and shelter to the bacteria.

(d)

These organisms are called fungi. They have a different mode of nutrition. They secrete digestive juices on the dead and decaying matter and convert it into a solution. Then they absorb the nutrients from it.

(d)

Gram, peas and moong beans are leguminous plants. Rhizobium present in roots of these plants convert atmospheric nitrogen into the soluble form. That's why farmers do not need to add nitrogen fertilizers to the soil when moong beans, peas or gram to be grown in soil. Only wheat plant need nitrogen from soil to complete its requirement.

(d)

Many plants (for example, fungi and bacteria) lack chlorophyll and cannot prepare their own food. Similarly, many plants derive their food by feeding on dead and decaying bodies, or by living in or on the bodies of other living organisms. Four such methods of heterotrophic nutrition are:

I. Saprophytic; II. Parasitic; III. Symbiotic; IV. Insectivorous.

(c)

Producers can make their own food. Grass can produce its own food. It has chlorophyll to trap energy from sunlight for photosynthesis. The other organism can not produce their own food because they do not have chlorophyll.

(d)

In the absence of photosynthesis there would not be any plants. The survival of almost all living organisms directly or indirectly depends upon the food made by the plants. Besides, oxygen which is essential for the survival of all living organisms is produced during photosynthesis. In the absence of photosynthesis, life would be impossible on the earth.

(b)

Amarbel does not have chlorophyll. It takes readymade food from the plant on which it is climbing. Since it deprives the host of valuable nutrients, it is called a parasite.

(d)

We use mushroom as vegetable in our food. Some fungi are useful to men as these are used in medicines and some are harmful and causing disease (ringworm) to us.

(d)

The fungal spores are generally present in the air. When they land on wet and warm things they germinated and grow.

(c)

It is a natural chemical process in which plants makes their food with the help of CO2and H2O in the presence of sunlight.

(b)

(b)

Variegated leaves have both green and white or yellow parts in the same leaf. It shows that chlorophyll is necessary for photosynthesis.

(b)

Explanation: All living organisms are made up of a basic tiny unit called cell. Many cells join together to form a tissue, which in turn form organ, organ system and in the last a complete organism. Nucleus, cell membrane and cytoplasm are the components of a cell.

(a)

Guard cells.

Explanation: Guard cells are the chlorophyll containing cells that surround the stomatal opening and help in the opening and closing of stomata.

(b)

Starch.

Explanation: During photosynthesis, carbohydrates get converted to starch which itself is a carbohydrate.

(b)

Explanation: A slimy green layer of patches is formed on the surface of stagnant waters and ponds by the growth of certain organisms called algae.