Plant Life
EXERCISE
SECTION I
A. Name the following.
1. The pigment present in photosynthetic cells of leaf.
= Chlorophyll;
2. Pores present on leaf surface for gaseous exchange.
= Stomata;
3. The food prepared by leaves during photosynthesis.
= Glucose;
4. Chemical used for starch test.
= Iodine solution;
5. A microorganism that respires anaerobically.
= Yeast;
6. The gas liberated during photosynthesis.
= Oxygen;
7. The energy currency of a cell.
= ATP(Adenosine Tri-Phosphate);
B. Choose the correct option.
1. Roots of legumes have a symbiotic association with
a. an algae. [ ]
b. a fungi. [ ]
c. Rhizobium. [✓]
d. None of them. [ ]
2. Autotrophic organisms are also known by this term.
a. Herbivores. [ ]
b. Consumers. [ ]
c. Producers. [✓]
d. Decomposers. [ ]
3. Venus flytrap is
a. an autotroph. [ ]
b. a heterotroph. [ ]
c. partly autotroph, partly heterotrophic. [✓]
d. a parasite. [ ]
4. In a food chain, producers are eaten by
a. herbivores. [✓]
b. carnivores. [ ]
c. saprophytes. [ ]
d. parasites. [ ]
5. Dodder is a
a. Parasite. [✓]
b. Saprophyte. [ ]
c. Carnivore. [ ]
d. Scavenger. [ ]
C. Fill in the blanks with the most appropriate word.
1. Yeast(Rhizobium/Yeast) is a microbe that carries out anaerobic respiration.
2. Gaseous exchange in plant occur through the Stomata(stomata/chloroplast).
3. Dodder(Dodder/Pitcher plant) is a parasitic plant.
4. Heterotrophs(Autotrophs/Heterotrophs) are organisms that depend on other organisms for nutrition.
5. Photosynthesis(Transpiration/Photosynthesis) and respiration almost complement each other.
6. Aerobic(Aerobic/Anaerobic) respiration releases 38 molecules of ATP.
7. Glucose is partially broken down in anaerobic(aerobic/anaerobic) respiration.
8. The source of all energy on the earth is the sun(sun/plants).
D. Write true of false. Correct the false statements by changing the first or last word/s only.
1. Plants are known as consumers. [F]
= Plants are known as producers.
2. During photosynthesis, chlorophyll, the green pigment helps in absorbing water. [F]
= During photosynthesis, chlorophyll, the green pigment helps in absorbing sunlight.
3. Respiration can happen in the presence or absence of oxygen. [T]
4. Xylem is the food conducting tissue in plants. [F]
= Phloem is the food conducting tissue in plants.
5. The process on which one organism feeds on another and is in turn is eaten is called food chain. [T]
6. The plants transport food in the form of starch. [F]
= The plants transport food in the form of glucose.
E. Given below is an example of a certain structure and the functional activity. On a similar pattern, complete the following.
E.g. Eye and vision.
1. Chlorophyll and Photosynthesis;
2. Stomata and Gaseous exchange;
3. Rhizobium and Symbiotic Nutrition;
4. Mitochondria and Respiration;
5. Dodder and Parasitic Nutrition;
F. Match the following.
=
|
Column A |
Column B |
|---|---|
|
1. Nutrition |
a. Chloroplast. [4] |
|
2. Autotrophs |
b. Leaf xylem. [ ] |
|
3. Parasite |
c. Leaf Epidermis. [5] |
|
4. Chlorophyll |
d. Indian Pipe. [ ] |
|
5. Stomata |
e. Dodder. [3] |
|
|
f. Green Plants. [2] |
|
|
g. Obtaining or providing food. [1] |
SECTION II
G. Define the following terms.
1. Photosynthesis.
= The process of using the energy of sunlight to convert water and carbon dioxide into glucose and oxygen is called photosynthesis.
2. Anaerobic respiration.
= The type of respiration in which glucose is broken down in the absence of oxygen is called anaerobic respiration.
3. Lenticels.
= Stomata are present mostly one the under surface of the leaves and on young stems. In older woody stems, stomata are replaced by lenticels.
4. Parasitic nutrition.
= In this type of nutrition, an organism lives on or inside the body of another living organism, called the host, to obtain nutrition directly from the host body.
5. Insectivorous plants.
= Insectivorous plants are a special group of plants that are partially autotrophic and partially heterotrophic.
H. Differentiate between the following pair of words based on what is given in the bracket.
1. Aerobic and anaerobic respiration. (word equation)
= Word equation of aerobic respiration is -
Glucose + Oxygen → Carbon dioxide + Water + Energy (38 ATP)
Word equation of anaerobic respiration is -
Glucose → Alcohol + Carbon dioxide + Energy (2 ATP)
2. Respiration and Photosynthesis. (end product)
= The end product of respiration are - energy, water and carbon dioxide.
The end product of photosynthesis are - Glucose and oxygen.
3. Autotrophic and heterotrophic nutrition. (definition)
= Autotrophic nutrition is a type of nutrition in which organisms make their own food form inorganic substances obtained from the environment.
Heterotrophic nutrition is a type of nutrition in which an organism depends on other organisms directly and indirectly for their food.
4. Saprophytic and symbiotic nutrition. (example)
= Example of saprophytic nutrition is Indian Pipe.
Example of symbiotic nutrition is Leguminous plants and Rhizobium.
5. Xylem and phloem. (material transport)
= Xylem transports water and minerals absorbed by the roots of a plant.
Phloem transports the food produced in the process of photosynthesis.
I. Short answer questions.
1. What is autotrophic nutrition?
= Autotrophic nutrition is a type of nutrition in which organisms make their own food form inorganic substances obtained from the environment.
2. Give the word equation for photosynthesis.
=
3. What is the fate of glucose produced during photosynthesis?
= The glucose produced during photosynthesis is transported from leaves to various parts of the plant through the conducting tissue, phloem. Plants convert the glucose into starch which they store in different organs, such as root, stem, or leaves.
4. Define heterotrophs. Give an example of a heterotroph plant.
= Heterotrophic nutrition is a type of nutrition in which an organism depends on other organisms directly and indirectly for their food. Such organisms are called heterotrophs.
An example of a heterotroph plant is Dodder.
5. What is the site of respiration?
= Respiration takes place partly in the cytoplasm of the cell and partly in the cell organelle, mitochondrion.
6. What is ATP? Give its full form.
= The energy that is released during the process of respiration is stored in the form of energy-rich molecules called ATP. The full form of ATP is Adenosine Tri-Phosphate.
J. Long answer questions.
1. What is the role of stomata, chlorophyll and sunlight in photosynthesis?
= Role of stomata : Stomata absorbs required quantity of carbon dioxide from air for the process of photosynthesis. It also releases oxygen which is produced in the process.
Role of Chlorophyll : Chlorophyll is the green pigment present in the chloroplast of leaf cells. This pigment imparts green colour to the leaves and young stem of plants. The main function of chlorophyll is to trap the light energy of the sun.
Role of sunlight : The light energy of the sun trapped by the chlorophyll is used to convert the raw materials, carbon dioxide and water, into chemical energy of food(glucose).
2. Explain any four significances of photosynthesis.
= Four significances of photosynthesis are -
❐ Photosynthesis is the only natural process that can capture and preserve sunlight as chemical energy. It is also the process by which organic food is synthesized by using inorganic raw materials.
❐ Energy of the sun that had been captured and preserved by plants, during photosynthesis, centuries ago are stored within fossil fuels (coal, petroleum, and natural gas). These fuels are used for our domestic and industrial energy needs.
❐ The oxygen evolved during photosynthesis is released released into the atmosphere. Hence, our atmosphere is replenished with oxygen by photosynthesis.
❐ This oxygen is used by animals and plants for cellular respiration. In the absence of photosynthesis, the oxygen level in the atmosphere would decrease drastically and life on earth would become impossible.
3. What are insectivorous plants? Give examples of two insectivorous plants, and explain their adaptations for capturing insects.
= Insectivorous plants are special group of plants that are partially autotrophic and partially heterotrophic.
Like all other green plants, they have green leaves that carry out photosynthesis. insectivorous plants grow in nitrogen deficit soil. In order to satisfy their nitrogen demand, they trap insects by various methods and digest them.
Their leaves are variously modified for capturing insects; they can be pitcher shaped (Pitcher plant) have trap doors (Bladderwort), may be hinged (Venus Flytrap) or bear sticky substances (Sundew) for trapping insects. Digestive enzymes secreted by the insectivorous plant then digest the trapped insect.
4. List any four differences between photosynthesis and respiration.
=
|
Photosynthesis |
Respiration |
|---|---|
|
1. It is the process by which plants manufacture food. |
1. It is the process by which food is broken down to liberate energy. |
|
2. It requires sunlight and thus can take place during the day. |
2. Sunlight is not necessary, and hence it takes place throughout the
day and night. |
|
3. Energy for the process is obtained from sunlight and is converted
into chemical energy of food. |
3. Energy is liberated during the process in the form of ATP. |
|
4. Carbon dioxide is used and oxygen is released. |
4. Oxygen is used and carbon dioxide is released. |
5. Describe an experiment to prove that oxygen is released during photosynthesis.
= Aim : To demonstrate that oxygen is evolved during photosynthesis.
Materials required : A fresh bunch of Hydrilla plant, a glass beaker, a glass test tube, a glass funnel, some water, a burning splint.
Procedure : 1. Take a fresh bunch of Hydrilla plant in a glass beaker filled with water.
2. Invert a glass funnel over it.
3. Fill a glass test-tube with water. Place your thumb on its mouth and invert it over the stem of the funnel.
4. Place the entire apparatus in sunlight. Leave the set up for about an hour.
Observation : Bubbles of gas emerge from the Hydrilla plant and collect in the inverted test tube. If we remove the test tube and introduce a burning splint inside the test tube, the splint will burn more brightly.
Conclusion : The splint burns brightly because of the presence of oxygen in the test tube. This proves that oxygen is evolved during photosynthesis.
PICTURE STUDY
1. The figure 1 and 2 below represents an experimental set up at the start and end of photosynthesis. Observe these and answer the following questions.
a. What is the aim of the experiment?
= To prove that chlorophyll is necessary for photosynthesis.
b. Name the chemical used for starch test.
= Iodine solution.
c. What change in colour of leaf is observed after starch test?
= On adding a drop of iodine solution, only the green parts of the leaf turn blue-black.
d. What conclusion will you draw from your observation in c. above?
= Iodine is an indicator that turns blue-black in the presence of starch. Starch is produced only in areas of the leaf with chlorophyll. The non-green parts of the leaf may have other pigments and do not produce starch.
e. Give the word equation for photosynthesis.
=
2. Figure 1 and 2 are plants with two different modes of nutrition. Answer the following questions.
a. Identify the plants 1 and 2.
= Plant 1 - Pitcher Plant;
Plant 2 - Dodder;
b. Why is the leaf modified into a pitcher shape in 1?
= The leaf is modified into a pitcher shape for capturing insects.
c. Name the mineral that is deficient in soils where the plant 1 grows.
= Nitrogen.
d. How does plant 2 draw its nourishment? What are such plants called?
= Dodder is a parasitic plant growing on the bodies of other autotrophic plants. Dodders possess special sucking roots called haustoria. These roots penetrate the host body to reach deeper into the conducting tissues from where they extract their food.
Such plants are called parasites.
3.
a. Identify the process occurring in the figure above.
= Photosynthesis.
b. What do the arrows indicate? Which of the following is a by product of the process?
i. Carbon dioxide. ii. Oxygen. iii. Water. iv. None of them.
= The arrows indicate that leaf takes sunlight, carbon dioxide and releases oxygen.
ii. Oxygen is the by product of the process.
c. Which cell organelle is significant for this process to take place?
= Chloroplast.
d. Name the structure in leaves through which gaseous exchange takes place. Draw a labelled diagram of it.
= Stomata.
Structure of Stomata