Multiple Choice Questions
In a germinating seed, the roots develop from:
Reason — In germinating seed, the radicle grows downward and develops the root.
In a germinating seed , the shoot develops from
Reason — In a germinating seed, the plumule grows upward and develops into the shoot.
Which one of the following is a monocotyledonous seed ?
Reason — Maize is a monocotyledonous seed while others are dicotyledonous seed.
If the cotyledons are pushed above the soil, then such type of germination is called:
Reason — In epigeal germination the cotyledons and the plumule comes out from the soil.
If the cotyledons remain under the soil, then such type of germination is called:
Reason — In hypogeal germination only plumule comes out of the soil to form leaves.
Pollen is produced in the :
Reason — Anther is the part of the stamen where pollen is produced.
Reproductive whorls of a flower are:
- Stamens and Carpels
- Sepals and Petals
- Sepals and Stamens
- Petals and Carpels
Stamen and Carpels
Reason — Stamen is a male reproductive part and Carpel is female reproductive part of the flower.
Which one of the following is a false fruit?
Reason — In apple, the main fleshy part of the fruit is formed from the thalamus, not from ovary, so it is known as false fruit.
In a seed, food is a generally stored in:
- Cotyledons or Endosperms
Cotyledons or Endosperm
Reason — Cotyledons or Endosperms stores nutrients which are required by the development of embryo during seedlings.
Short Answer Questions
Given below is a longitudinal section of a bean seed. Label the parts marked 1 to 5 and write their functions.
The parts marked 1 to 5 are:
Their functions are as follows:
- Testa — It protects the seed from insect and bacteria as well as from mechanical injury.
- Plumule — It develops into the shoot.
- Radicle — It develops into the root.
- Micropyle — It absorbs and allows the entry of as much water as is required for germination.
- Cotyledons — They contain stored food material which is used by the seedlings for growth.
Name the following:
- A seed which shows hypogeal germination.
- A monocot seed.
- A dicot seed.
- A seed which shows epigeal germination.
- Pea seed
- Maize grain
- Bean seed
- Papaya seed
Differentiate between Radicle and Plumule
Differences between Radicle and Plumule are:
|The radicle grows downward.||The plumule grows upward.|
|The radicle develops into root.||The plumule develops into shoot.|
Differentiate between Hilum and Micropyle
Differences between Hilum and Micropyle are:
|Hilum is a scar which is present on the inner concave side of the seed.||Micropyle is a small pore which is present above the hilum.|
|Hilum is the place where the seed was attached to the fruit wall.||Micropyle absorbs and allows the entry of as much water as is required for germination.|
Differentiate between Testa and tegmen
Differences between Testa and Tegmen are:
|Testa is the protective outer covering of the seed coat.||Tegmen is the protective inner part of the seed coat.|
|Testa is smooth, thicker and impermeable.||Tegmen is thin and membranous.|
|Testa protects the seed from insect, bacteria as well as mechanical injury.||Tegmen protects the embryo from dehydration and mechanical damages.|
Give two main functions of a fruit.
Two main functions of a fruit are:
- Fruit protects seed from the unfavourable environmental condition.
- Fruit stores food inside them.
Match the columns:
|Column A||Column B|
|a) Radicle||(i) Shoot|
|b) Plumule||(ii) Store food material|
|c) Cotyledon||(iii) Root|
|d) Testa||(iv) Absorb water needed for germination|
|e) Micropyle||(v) Protection of seed|
|Column A||Column B|
|a) Radicle||(iii) Root|
|b) Plumule||(i) Shoot|
|c) Cotyledons||(ii) Store food material|
|d) Testa||(v) Protection of seed|
|e) Micropyle||(iv) Absorb water needed for germination|
Radicle emerges out of the seed earlier than plumule. State one advantage served by this.
The Radicle emerges out of the seed earlier than the plumule and absorbs water and essential nutrients from the soil. This helps the plumule to grow and allows for photosynthesis to occur by providing raw materials.
State whether the following statements are True or False.
- Some seeds have no cotyledons.
- Warmth is necessary for the germination of seed.
- All seed have two cotyledons.
- Oxygen is necessary for the germination of seed.
Reason — Seeds always have cotyledons. Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.
Reason — Warmth or a suitable temperature is necessary for germination of seeds because enzymes are inactive at low temperatures and get destroyed at higher temperatures.
Reason — Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.
Reason — Oxygen is required to oxidize the stored food and release energy required for the growth of the embryo.
State one function of the following:
- Radicle is the part of the seed which develops into root.
- Cotyledons contain stored food material which is used by the seedling for growth.
- Endosperm stores food in the form of starch.
- Micropyle absorbs and allows the entry of as much water as is needed for germination.
The three conditions necessary for germination of seeds are (tick the correct answer):
- Oxygen, suitable temperature and water.
- Good soil, water and air.
- Good soil, suitable temperature and light.
- Light, oxygen and temperature.
- Oxygen, carbon dioxide and light.
Oxygen, suitable temperature and water
Reason — Seeds need water for germination as most chemical reactions occur in water. Oxygen is required to oxidize the stored food and release energy required for the growth of the embryo. Suitable temperature is necessary for germination of seeds because enzymes are inactive at low temperatures and get destroyed at higher temperatures.
Name the part of the seed from which the following are given out:
In the spaces provided below, draw labelled diagrams to show the three stages in the germination of any seed you have observed.
Labelled diagrams showing the three stages in the germination of any seed are shown below:
Long Answer Questions
What is meant by pollination? Name the two types of pollination.
Pollination is the transfer of pollen grains from the anthers to the stigma of a flower. The two types of pollination are:
- Self pollination
- Cross pollination
Imagine all the seeds produced by a plant happen to fall under the same plant and sprout into new plants. Mention any two problems that will be faced by the new plants.
The two main problems that will faced by the new plant are:
- New plants will lack space for their growth because comparatively large number of plants are growing at a particular place.
- The new plants will face competition among themselves to get nutrient from the soil which will hamper their growth and development.
What is a flower? Draw a typical flower and label its different parts.
Flower is a specialized shoot in which the leaves are modified into floral structures. It is the reproductive organ of the plant.
Labelled diagram of a flower is shown below:
With the help of a suitable labelled diagram, describe the structure of a dicot seed.
Taking Bean seed as an example of a dicot seed, below is its labelled diagram:
The structure of a bean seed is described below:
- The bean seed is protected by a thin, greenish outermost covering called seed coat. It protects the seed from insects and bacteria as well as from mechanical injury.
- The seed coat is divided into two parts, the outer part is called Testa and inner part is called Tegmen. Tegmen is a thin membrane that lies under the Testa.
- On the inner concave side of the seed, there is a scar called Hilum which marks the place where the seed was attached to the fruit wall.
- Above the hilum is a small pore called Micropyle. The Micropyle absorbs and allows the entry of as much water as is required for germination.
- On removing the testa and tegmen from a soaked bean seed, the seed is made up of two fleshy seed leaves called the Cotyledons. They contain stored food material which is used by the seedling for growth.
- In between the two cotyledons is located the delicate embryo which consist of a Radicle and Plumule. The radical develops into a root, while the plumule develops into a shoot.
Define germination? Name the two types of germination. Explain with example.
The process by which an embryo within the seed becomes active and grows into a young plant is called germination. The two types of germinations are:
- Epigeal Germination — Put some bean seeds in moist cotton placed in a petri dish. After about two days, the radicle grows downwards and develops the roots, while the plumule grows upwards and develops into the shoot. It is seen that the cotyledons are pulled above the surface of the ground. This type of germination in which the cotyledons are pushed above the soil is called Epigeal Germination.
- Hypogeal Germination - Soak some maize grains in water for about 24 hours. The stored food in the endosperm is used by the radicle and plumule for their growth. The radicle grows downward while the plumule grows upward and forms the first leaf. This type of germination is called hypogeal germination, as the cotyledons remains under the soil. The plumule only comes out of the soil to form leaves of the plant.
What are the three conditions necessary for the germination of seeds?
For the germination of the seeds the three necessary conditions are:
- Water — All living things required water to carry out their life processes. Most chemical reactions occur in water. So seeds also need water during germination.
- Oxygen — Seed also needs air for the germination of seed. The oxygen present in the air is used to oxidize the stored food and thus release energy. The energy is required for the growth of the embryo.
- A Suitable Temperature — It is necessary for all chemical activities assisted by enzymes. Enzymes are inactive at low temperatures and get destroyed at higher temperatures. They act best between 35° and 40°C.
Give the main differences between Hypogeal and Epigeal germination.
Differences between Hypogeal and Epigeal germination are:
|The Cotyledons remains under the soil.||The Cotyledons are pushed above the soil.|
|Epicotyl elongates faster than Hypocotyl, hence cotyledons remain below.||Hypocotyl elongates faster than Epicotyl, hence cotyledons get pulled above.|
|Example - Maize, Rice.||Example - Papaya, Bean.|
State the location of the following in a flower:
- Sepals — Sepals are located in the Calyx which is the outermost whorl of the flower.
- Petals — Petals are located in the Corolla which is the second inner whorl of the flower.
- Anthers — Anthers are located at the tip of the stamens in the third whorl of the flower, inner to the petals.
- Stigma — Stigma is located in the fourth and innermost whorl of the flower, in the pistil at the tip of the style.
Given below is the diagram of a typical flower. Label the parts marked by guidelines.
Labelled diagram of the flower is shown below:
Give the difference in function between Ovary and Ovule.
Difference in function between Ovary and Ovule is:
|Ovary after fertilization turns into a fruit.||Ovule after fertilization turns into a seed of a fruit.|
Give the difference in function between Petals and Sepals.
Difference in function between Petals and Sepals is:
|The petal makes the flower attractive and hence attract insects for pollination.||The sepal encloses the inner parts of the flower to provide necessary protection to the growing bud.|
Give the difference in function between Filament and Style.
Difference in function between Filament and Style are:
|The filament bears anther at its tip which produce pollen grains. Pollen grains contain the male gametes.||The style transfers the male gametes of the pollen grains into the ovary.|
|Filament comes under the male reproductive part of the flower.||Style comes under the female reproductive part of the flower.|
Give the difference in function between pollen grain and ovule.
Difference in function between pollen grain and ovule are:
|It contains the male gametes.||It contains the female gametes.|
|Pollen grains deliver male gametes from stamen of the flower to ovule.||Ovule comes under the female reproductive part of the flower.|