The Flower

In a germinating seed, the roots develop from:

1. Radicle
2. Plumule
3. Tegmen
4. Hilum

Answer

Radicle

Reason — In germinating seed, the radicle grows downward and develops the root.
Plumule develops into the shoot. Tegmen is inner seed coat. Hilum is scar showing attachment of seed to fruit.

In a germinating seed, the shoot develops from

1. Radicle
2. Plumule
3. Tegmen
4. Hilum

Answer

Plumule

Reason — In a germinating seed, the plumule grows upward and develops into the shoot.
Radicle forms the root. Tegmen is inner seed coat. Hilum is scar of attachment.

Which one of the following is a monocotyledonous seed ?

1. Bean
2. Pea
3. Maize
4. Gram

Answer

Maize

Reason — Maize is a monocotyledonous seed while others are dicotyledonous seed.
Bean, gram, pea are dicots.

If the cotyledons are pushed above the soil, then such type of germination is called:

1. Epigeal
2. Hypogeal
3. Perigeal
4. Progeal

Answer

Epigeal

Reason — In epigeal germination the cotyledons and the plumule comes out from the soil.
In hypogeal germination, the cotyledons remain below the soil surface. The epicotyl (part above cotyledons) grows and forms the shoot.

If the cotyledons remain under the soil, then such type of germination is called:

1. Epigeal
2. Hypogeal
3. Perigeal
4. Progeal

Answer

Hypogeal

Reason — In hypogeal germination only plumule comes out of the soil to form leaves.
In Epigeal cotyledons come above soil. In Hypogeal cotyledons remain below soil.

Pollen is produced in the :

1. Filament
2. Style
3. Pistil
4. Anther

Answer

Anther

Reason — Anther is the part of the stamen where pollen is produced.
Filament supports the anther. Style is part of female organ, connects stigma and ovary. Pistil is female reproductive part as a whole.

Reproductive whorls of a flower are:

1. Stamens and Carpels
2. Sepals and Petals
3. Sepals and Stamens
4. Petals and Carpels

Answer

Stamen and Carpels

Reason — Stamen is a male reproductive part and Carpel is female reproductive part of the flower.
Sepals and Petals are non-reproductive (accessory whorls). Sepals and Stamens include only one reproductive whorl, not both. Petals and Carpels are incorrect because petals are non-reproductive.

Which one of the following is a false fruit?

1. Tomato
2. Apple
3. Potato
4. Pea

Answer

Apple

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.
Tomato is true fruit (develops from ovary). Potato is not a fruit; it is a stem tuber. Pea → true fruit (legume).

In a seed, food is generally stored in:

1. Radicle
2. Plumule
3. Fruit
4. Cotyledons or Endosperms

Answer

Cotyledons or Endosperm

Reason — Cotyledons or Endosperms stores nutrients which are required by the development of embryo during seedlings.
Radicle develops into root, not for storage. Plumule develops into shoot, not for storage. Fruit protects seeds, not inside seed.

The floral stalk is technically termed as :

1. Petiole
2. Pedicel
3. Peduncle
4. Thalamus

Answer

Pedicel

Reason — The floral stalk is technically termed as Pedicel.
Petiole is stalk of a leaf. Peduncle is main stalk of an inflorescence or flower cluster. Thalamus is swollen base of flower where floral parts are attached.

Which of the following is the fleshy part of a mango ?

1. Pericarp
2. Endocarp
3. Epicarp
4. Mesocarp

Answer

Mesocarp

Reason — In the case of mango, the mesocarp are pulpy.
Pericarp is the entire fruit wall. Endocarp is hard inner stone around seed. Epicarp is outer skin.

The food material stored in a maize grain is :

1. Protein
2. Fat
3. Starch
4. Cellulose

Answer

Starch

Reason — The upper larger part of the maize grain, called the endosperm stores food in the form of starch.
Protein is present in small amount. Fat is present in traces. Cellulose is structural component of cell walls, not storage food.

Gynoecium is made up of :

1. Carpels
2. Pistils
3. Stamens
4. Both (1) and (2)

Answer

Both (1) and (2)

Reason — Gynoecium is made up of the carpel or the pistil.
Carpels are the basic units of gynoecium. Pistils may consist of one or more carpels (not always the basic unit). Stamens is the male part.

Which part of the flower attracts insects for pollination ?

1. Calyx
2. Corolla
3. Stamens
4. Stigma

Answer

Corolla

Reason — Corolla is made up of structures called petals. The petals make the flower attractive and hence attract insects for pollination.
Calyx is green sepals that protect the bud. Stamens is male reproductive part, not for attraction. Stigma receives pollen, not for attraction.

Which of the following is not a necessary condition for the germination of seeds ?

1. Air
2. Water
3. Soil
4. Warmth

Answer

Soil

Reason — Water, air, and favourable temperature are the three necessary conditions for the germination of a seed.
Air is needed for respiration during germination. Water is needed to activate enzymes and start growth. Warmth is needed for enzyme activity.

Assertion: Androecium is the third whorl of the flower. It is made up of stamens which produce pollen grains at the time of reproduction.

Reason: Pollination and fertilization are essential steps of reproduction in plants during which male gametes fuse with the ovule and a seed is produced inside the ovary.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true but R is not the correct explanation of A.

Reason — A is true as the androecium is the third whorl of a flower and consists of stamens that produce pollen grains.
R is true as pollination and fertilization are essential processes in plant reproduction, leading to seed formation inside the ovary.

The reason does not correctly explain why the androecium is the third whorl or that it is made of stamens. It only describes the process of reproduction. Therefore, Both A and R are true but R is not the correct explanation of A is the correct option.

Assertion: Cross pollination occurs between different flowers of two plants of the same species. These flowers get pollinated by wind, water, insects, etc.

Reason: Wind pollination always occurs between the flowers of plants occurring in close vicinity and not among the flowers of distant plants.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is true but R is false.

Reason — A is true as Cross-pollination means transfer of pollen grains from the anther of one flower to the stigma of a flower on another plant of the same species. This transfer is helped by agents called pollinating agents such as wind, water, insects, etc.
R is false as wind can carry pollen to nearby plants, and sometimes to plants located far away. So wind pollination is not restricted only to nearby plants.

Therefore, A is true but R is false is the correct option.

Assertion: All aquatic plants get pollinated only by the most easily available pollinating agent-water.

Reason: Flowers of some aquatic plants are exposed to air and can be pollinated by insects.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is false but R is true.

Reason — A is false as some aquatic plants have flowers that rise above the water surface and are pollinated by insects or wind.
R is true as many aquatic plants produce flowers above the water surface, allowing insects to pollinate them.

Therefore, A is false but R is true is the correct option.

Assertion: The yellow, fleshy, edible part of the peach is mesocarp which develops from the wall of the ovary.

Reason: Mesocarp is the middle layer of the pericarp between the protective epicarp and stony endocarp.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Reason — A is true because in peach, the fruit wall develops from the ovary wall and is called the pericarp. The pericarp has three layers: Epicarp, Mesocarp, Endocarp. Mesocarp is fleshy, edible part.
R is true as mesocarp is the middle layer of the pericarp between the protective epicarp and stony endocarp.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

Assertion: Both proteins and starch are richly found in the endosperm as well as the cotyledon of the maize grain.

Reason: Maize grain is an example of an endospermic seed. Hence, proteins and starch are stored in the endosperm which can be easily utilized by the developing embryo.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is false but R is true.

Reason — A is false because in maize grain, food like starch and proteins are mainly stored in the endosperm, not richly in the cotyledon. Maize is a monocot seed with only one cotyledon called the scutellum, which mainly absorbs food from the endosperm for the embryo.
R is true as maize is an endospermic (albumin) seed, meaning the endosperm persists and stores food materials such as: starch and proteins.

Therefore, A is false but R is true is the correct option.

Match the terms given in column A with those of column B.

Answer

Name the following:

(i) Four whorls of a bisexual flower.

(ii) Four pollinating agents.

(iii) Two types of seeds on the basis of the number of cotyledons.

(iv) Two types of germination.

(v) Two types of pollination.

Answer

(i) Calyx, Corolla, Androecium, and Gynoecium

(ii) Insects, Wind, Water, and Animals

(iii) Monocotyledonous seeds and Dicotyledonous seeds

(iv) Epigeal germination and Hypogeal germination

(v) Self pollination and Cross pollination

Given below are sets of four terms. Choose the odd one and write the category of the remaining terms :

(i) Epicarp, Epicalyx, Endocarp, Mesocarp

(ii) Anther, Ovary, Stigma, Style

(iii) Bean, Gram, Rice, Pea

(iv) Tegmen, Cotyledones, Testa, Thalamus

(v) Apple, Mango, Guava, Litchi

Answer

(i) Odd one — Epicalyx
Category of remaining — Parts of a Pericarp or Fruit wall

(ii) Odd one — Anther
Category of remaining — Parts of the Carpel

(iii) Odd one — Rice
Category of remaining — Dicotyledonous seeds

(iv) Odd one — Thalamus
Category of remaining — Parts of a seed

(v) Odd one — Apple
Category of remaining — True fruits with edible part formed from the ovary

Correct the following statements by changing the first/last word only

(i) Ovary is the part of a flower from where the petals and other floral parts arise.

(ii) A fruit is the ripened ovule.

(iii) The plumule of an embryo develops into the root system.

(iv) Hilum is a small pore which allows the entry of water inside the seed.

(v) Enzymes act best at a temperature between 45° to 50° C.

Answer

(i) Thalamus is the part of a flower from where the petals and other floral parts arise.

(ii) A fruit is the ripened ovary.

(iii) The radicle of an embryo develops into the root system.

(iv) Micropyle is a small pore which allows the entry of water inside the seed.

(v) Enzymes act best at a temperature between 35° to 40° C.

Given below is a longitudinal section of a bean seed. Label the parts marked 1 to 5 and write their functions.

Answer

The parts marked 1 to 5 are:

1. Testa
2. Plumule
3. Radicle
4. Micropyle
5. Cotyledon

Their functions are as follows:

1. Testa — It protects the seed from insect and bacteria as well as from mechanical injury.
2. Plumule — It develops into the shoot.
3. Radicle — It develops into the root.
4. Micropyle — It absorbs and allows the entry of as much water as is required for germination.
5. Cotyledons — They contain stored food material which is used by the seedlings for growth.

Name the following:

(a) A seed which shows hypogeal germination.

(b) A monocot seed.

(c) A dicot seed.

(d) A seed which shows epigeal germination.

Answer

(a) Pea seed

(b) Maize grain

(c) Bean seed

(d) Papaya seed

Differentiate between Radicle and Plumule

Answer

Differences between Radicle and Plumule are:

Differentiate between Hilum and Micropyle

Answer

Differences between Hilum and Micropyle are:

Differentiate between Testa and tegmen

Answer

Differences between Testa and Tegmen are:

Give two functions of a fruit.

Answer

Two main functions of a fruit are:

1. Fruit protects seed from the unfavourable environmental condition.
2. Fruit stores food inside them.

Radicle emerges out of the seed earlier than plumule. State one advantage served by this.

Answer

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.

(a) Some seeds have no cotyledons.

(b) Warmth is necessary for the germination of seeds.

(c) All seeds have two cotyledons.

(d) Oxygen is necessary for the germination of seeds.

Answer

(a) False
Reason — Seeds always have cotyledons. Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.

(b) True
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.

(c) False
Reason — Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.

(d) True
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:

(a) Radicle

(b) Cotyledons

(c) Endosperm

(d) Micropyle

Answer

(a) Radicle is the part of the seed which develops into root.

(b) Cotyledons contain stored food material which is used by the seedling for growth.

(c) Endosperm stores food in the form of starch.

(d) 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):

(a) Oxygen, suitable temperature and water.

(b) Good soil, water and air.

(c) Good soil, suitable temperature and light.

(d) Light, oxygen and temperature.

(e) Oxygen, carbon dioxide and light.

Answer

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:
(a) Roots
(b) Leaves

Answer
(a) Radicle
(b) Plumule

In the spaces provided below, draw labelled diagrams to show the three stages in the germination of any seed you have observed.

Complete Seed

Radicle Emerged

Plumule Emerged

Answer

Labelled diagrams showing the three stages in the germination of any seed are shown below:

Define the terms given below:

(i) Fruit

(ii) Seed

(iii) Fertilization

(iv) Hilum

(v) Dry fruit

Answer

(i) Fruit — A fruit is the ripened ovary. It is a sweet, fleshy, edible plant part. A fruit contains two parts, a pericarp or fruit wall and the seeds.

(ii) Seed — A seed is defined as a fertilized ovule, from which a new plant of the same kind can grow.

(iii) Fertilization — The fusion of male and female sex cells (gametes) is called fertilization.

(iv) Hilum — Hilum is a scar on the inner concave side of the seed, which marks the place where the seed was attached to the fruit wall.

(v) Dry fruit — A dry fruit is the one in which the pericarp is not pulpy and encloses the seeds. For example, the pea pod.

What is meant by pollination? Name the two types of pollination.

Answer

Pollination is the transfer of pollen grains from the anthers to the stigma of a flower. The two types of pollination are:

1. Self pollination
2. 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.

Answer

The two main problems that will faced by the new plant are:

1. New plants will lack space for their growth because comparatively large number of plants are growing at a particular place.
2. 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.

Answer

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.

Answer

Taking Bean seed as an example of a dicot seed, below is its labelled diagram:

The structure of a bean seed is described below:

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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 examples.

Answer

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:

1. 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.
2. 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?

Answer

For the germination of the seeds the three necessary conditions are:

1. 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.
2. 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.
3. 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.

Answer

Differences between Hypogeal and Epigeal germination are:

State the location of the following in a flower:

(a) Sepals

(b) Petals

(c) Anthers

(d) Stigma

Answer

(a) Sepals — Sepals are located in the Calyx which is the outermost whorl of the flower.

(b) Petals — Petals are located in the Corolla which is the second inner whorl of the flower.

(c) Anthers — Anthers are located at the tip of the stamens in the third whorl of the flower, inner to the petals.

(d) Stigma — Stigma is located in the fourth and innermost whorl of the flower, in the pistil at the tip of the style.

Give the difference in function between Ovary and Ovule.

Answer

Difference in function between Ovary and Ovule is:

Give the difference in function between Petal and Sepal.

Answer

Difference in function between Petal and Sepal is:

Give the difference in function between Filament and Style.

Answer

Difference in function between Filament and Style are:

Give the difference in function between pollen grains and ovule.

Answer

Difference in function between pollen grains and ovule are:

Draw a neat diagram of the 'longitudinal section of a maize grain' and label its seven important parts. Answer the following questions :

(i) Name the structure which divides the embryonic and endospermic region of the grain.

(ii) Among the parts labelled by you above, which one of them is protienaceous in nature ?

(iii) Name the food component which is stored in the endosperm.

(iv) Mention the part of the seed which develops into the root.

(v) Why do we call it as a 'grain' and not as a seed or fruit ?

Answer

Diagram of Longitudinal section of a maize grain:

(i) The epithilial layer divides the embryonic and endospermic region of the grain.

(ii) Aleurone layer is protinaceous in nature.

(iii) Endosperm stores food in the form of starch.

(iv) Radicle is the part of the seed which develops into the root.

(v) We call it 'maize grain' as the seed coat is fused together with the pericarp, making it indistinguishable.

Given alongside is a figure of the vertical section of a typical bisexual flower. Study the same and answer the following questions :

(i) Label the guidelines 1 to 9.

(ii) Which of the above labelled parts constitute the pistil? Write the numbers and names of those parts.

(iii) Name the part which produces pollen grains.

(iv) Is it a complete/incomplete flower ? Give reason in support of your answer.

(v) Write one important role of the part labelled as 6.

Answer

(i) The parts 1 to 9 given in the diagram are:
1 → Thalamus
2 → Sepal
3 → Filament
4 → Anther
5 → Petal
6 → Stigma
7 → Anther
8 → Style
9 → Ovule

(ii) The parts in the given figure that constitute the pistil are:
6 → Stigma,
8 → Style, and
9 → Ovules.

(iii) The anther contains pollen sacs which produce a yellow, powdery material consisting of pollen grains.

(iv) The given figure shows a complete flower. This is because all four whorls viz. calyx, corolla, androecium and gynoecium are present in the same flower.

(v) One important role of Stigma is that it receives the pollen grains during pollination.

The figure given alongside represents the vertical section of a fruit. Study the same and answer the following questions :

(i) Identify the fruit and mention whether it is a true fruit or a false fruit.

(ii) Label the guidelines 1, 2, 3 and 4.

(iii) Write the collective name for the parts shown as 1, 2 and 3.

(iv) Name the part of the flower which matures into part 4.

(v) Which of the above labelled parts of the fruit is fleshy and edible ?

Answer

(i) The given fruit is Mango. Mango is a true fruit as the fleshy part and the seed both develop from the ovary.

(ii) The parts 1 to 4 are:
1 → Epicarp
2 → Mesocarp
3 → Endocarp
4 → Seed

(iii) Epicarp, Mesocarp, and Endocarp are collectively known as the Pericarp.

(iv) The ovule that contains the fertilised cell develops into a seed.

(v) Mesocarp is the sweet, fleshy and edible layer.

One winter morning, Shweta and her mother were sitting in their garden when they noticed fresh pea flowers blooming. Over the next few days, they watched some of these flowers slowly develop into tiny green pea pods. Together, they began tracking each stage of this change and observed how pollination and fertilization occur in plants. Answer the following questions:

(i) What role do insects play in the development of a flower into a fruit?

(ii) Mention the male and female gametes of the flower.

(iii) What is the function of the pollen tube during fertilization?

(iv) What happens to the ovary once fertilization is completed?

(v) Shweta's mother claimed that the pea pod is a fruit and not a vegetable. Explain.

Answer

(i) Insects act as pollinating agents. When the insect visits a flower to collect nectar, the pollen grains stick to its mouth-parts, wings, legs, etc. When this insect visits another flower of the same kind, the pollen grains from its body may fall on its stigma and bring about fertilization. Transfer of pollen by insects is called insect-pollination.

(ii) The androecium is called the male reproductive part of the flower. The gynoecium is called the female reproductive part of the flower.

(iii) Pollen grains germinate to produce pollen tubes. One of the pollen tubes continue to develop downwards into the style. This pollen tube carries the male gametes. The pollen tube finally reaches the ovary.

(iv) The ovary after fertilization becomes larger and develops into a fruit. The ovule containing the fertilized cell develops into a seed.

(v) A pea pod is a fruit because it develops from the ovary of the flower after fertilization and contains seeds.