Nutrition in Plants
Fill in the blanks:
(a) Green plants are called _ autotrophs __ since they synthesize their own
food.
(b) The foods synthesized by the plants are stored as starch .
(c) In photosynthesis solar energy is captured by the pigment called
___ chlorophyll
(d) During photosynthesis plants take in ____CO2________ and release _ O2
Name the following:
(i) A parasitic plant with yellow, slender, tubular stem.------- Cascuta
(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.-------- Insectivorous plants
(iii) The pores through which leaves exchange gases. ------- Stomata
(iv) A plant that has both autotrophic as well as heterotrophic mode of
nutrition. --- Pitcher plant.
(v) An organism that live is an association of an alga and a fungus ---------lichen
(vi) Amarbel is an example of: ----parasites
(vii) The plant which traps and feeds on insects is----- pitcher plant
Match the items in column I with those in column II:
Chlorophyll ---–
Leaf.
Nitrogen –––
Bacteria.
Amarbel ––– Parasite.
Animals –––
Heterotrophs.
Insects –––
Pitcher Plant
What is Nutrients?
Food is essential for all living organisms. Carbohydrates, proteins, fats,
vitamins and minerals are components of food. The chemical substance
present in components of food is necessary for our body and is called
nutrients.
How humans and animals are are directly or indirectly dependent on plants.
All living organisms require food. Plants can make their food themselves but
animals including humans cannot. They get it from plants or animals that eat
plants. Thus, humans and animals
are directly or indirectly dependent on plants.
Why do we need food ?
Living organisms need food to build their bodies, to grow, to repair damaged
parts of their bodies and provide the energy to carry out life processes.
What is food ?
Food is the source of energy and every cell of an organism gets energy by the
breakdown of glucose. The cells use this energy to carry out vital activities of
life.
What is Nutrition?
Nutrition is the sum of all including taking food by an organism and its
utilization by the body.
The mode of nutrition in which organisms make food themselves from
simple substances is
called autotrophic nutrition. Ex plants.
The mode of nutrition in which organisms take in ready made food prepared
by the plants
called heterotrophic nutrition. Ex animals
Whether food is made in all parts of a plant or only in certain parts?
Only certain part plant like leaves having green pigment chlorophyll. so
Leaves are called the food factories of plants.
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.
How do plants obtain the raw materials from the surroundings?
Water and minerals present in the soil are absorbed by the roots and
transported to the leaves.
Carbon dioxide from air is taken in through the tiny pores present on the
surface of the leaves. Such pores are called stomata. These pores are
surrounded by ‘guard cells’
How do the raw materials transport them to the food factories of the plants?
Plants have pipe-like vessels to transport water and nutrients from the soil.
The vessels are
made of special cells, forming the vascular tissue. The vascular tissue for the
transport of water and nutrients in the plant is called the xylem. The vascular
tissue for the transport of water and nutrients in the plant is called the xylem.
Thus, xylem and phloem transport substances in plants
What is cell ?
The bodies of living organisms are made of tiny units called cells therefore
Cell are called the building blocks of living organism.
Cells can be seen only under the microscope. Some organisms are made of
only one cell. They are called Unicellular Ex. Amoeba, Paramecium etc
Living organism made up of many cells are called Multi cellular like man,
tree etc
What is the cell membrane?
The cell is enclosed by a thin outer boundary, called the cell membrane Most
cells have a distinct, centrally located spherical structure called the
nucleus The nucleus is surrounded by a jelly-like substance called cytoplasm.
What is tissue ?
A tissue is a group of cells that perform specialized function in an organism.
For example, the vascular tissue for the transport of water and nutrients in the
plant is called the xylem.
What are the main requirements of photo synthesis?
Chlorophyll, sunlight, carbon dioxide and water are necessary to carry out the
process of
Photosynthesis.
Explain the process of Photosynthesis?
Carbon dioxide from air is taken in through stomata. chlorophyll helps leaves
to capture the energy of the sunlight. This energy is used to synthesize
(prepare) food from carbon dioxide and water. Since the synthesis of food
occurs in the presence of sunlight, it is called photosynthesis
Carbon dioxide + water ---------sunlight/chlorophyll-àCarbohydrate + oxygen
Here the carbohydrates ultimately get converted into starch
How would you test the presence of starch on leaves?
Put 2-3 drops of dilute iodine solution on the leaves. Appearance of a blueblack colour indicates presence of starch in the leaves.
Why are leaves called the food factories of plants? Explain.
Leaves are called the food factories of plants due to following functions
ü Green leaves have all the raw materials neccessary to carry the process of
photosynthesis.
ü They have chlorophyll (green pigment) which captures the energy of
sunlight.
ü Leaves consist of tiny pores called stomata on their surface.
ü Carbon dioxide from air is taken in through stomata.
ü Water and minerals are absorbed by the roots from the soil and transported
to the leaves by vessels.
ü
Why sun is called the ultimate source of energy for all living organisms?
The solar energy is captured by the leaves and stored in the plant in the form
of food. and this in turn use by other organism to get food to obtain energy
Thus, sun is the ultimate source of energy for all living organisms.
Why algae are green in colour?
Algae contain chlorophyll which gives them the green colour. It can also
prepare their own food by photosynthesis.
What are the main components presents in carbohydrates?
The main components presents in carbohydrates are carbon, hydrogen and
oxygen.
From where do the plants obtain nitrogen?
Soil has certain bacteria that convert gaseous nitrogen into a usable form and
release it into the soil. These soluble forms are absorbed by the plants along
with water.
By adding fertilizers rich in nitrogen to the soil farmers also made nitrogen
available for plants
What is parasitic nutrition?
The mode of by which parasitic organism get and synthesize their food is
called parasitic nutrition. Example Cucuta It does not have chlorophyll It
takes readymade food from the plant
on which it is climbing. The plant on which it climbs is called a host.
How Pitcher plants get their nutrition?
There are a few plants which can trap insects and digest them. Such plants
may be green or of some other colour. Such insect-eating plants are called
insectivorous plants.
Example Pitcher plant
When an insect lands in the pitcher, the lid closes and the trapped insect gets
entangled into the hair. The insect is digested by the digestive juices secreted
in the pitcher.
Why does the pitcher plant feed on insects though it is green?
The pitcher plant does not get all the required nutrients especially those of
nitrogen from the soil, hence it feeds on insects.
What is saprotrophic nutrition? What is the mode of nutrition in fungi?
This mode of nutrition in which organisms take in nutrients in solution form
from dead and decaying matter is called saprotrophic nutrition. Plants which
use saprotrophic mode of
nutrition are called saprotrophs. Example Fungi that secrete digestive juices
on the dead
and decaying matter and convert it into a solution. Then they absorb the
nutrients from it.
How do fungi appear suddenly during the rainy season?
Air generally consists of fungal spores. When these spores come in contact
with warm things they germinate and grow. During rainy season, there are
more chances of things getting wet.
Hence, fungi appear more in rainy season.
What do you under stand by symbiotic relationship present in some
organism?
Some organisms live together and share shelter and nutrients. This is called
symbiotic relationship . E.g. an alga, and a fungus live together fungus
provides shelter, water and
Minerals to the alga and, in return, the alga provides food which it prepares
by photosynthesis.
What is Symbiosis?
Symbiosis - It is the type of nutrition in which two different kinds of depend
on each other for their nutrition. In this both the organisms are benefitted by
each other e.g., lichen. In this one alga and one fungus live together and
remain in symbiotic relationship.
How nutrients are replenished in soil?
Nutrients are replenished in soil by following ways
1.By spreading manure or fertilizers that contain nutrients such as nitrogen in
the fields
2.By The bacterium Rhizobium that can take atmospheric nitrogen and
convert it into a soluble form.
How do leguminous plants help replenishing soil fertility?
Rhizobium cannot make its own food. So it lives in the roots of gram, peas,
moong beans
and other legumes and provides them with nitrogen. In return, the plants
provide food and
shelter to the bacteria
Distinguish between a parasite and a saprotrophs
Parasite
1. A parasite takes readymade food from the organism on which it feeds.
2. They feed on a living organism.
3. The organism on which it feeds is called host.
4. It deprives the host of valuable nutrients.
saprotrophs
1. They secrete the digestive juices on the matter they live and convert it into
a solution and then absorb it.
2. They feed on dead and decaying organism.
3. They do not feed on a living organism.
4. There is no host at all.
Why algae are green in colour?
Algae are green in colour as they contain chlorophyll which gives them the
green colour. Algae can also prepare their own food by photosynthesis.
Slimy, green patches in ponds or in other stagnant water bodies are algae.