The Flower

1. Odd one — Epicalyx
   Category of remaining — Parts of a Pericarp or Fruit wall

2. Odd one — Anther
   Category of remaining — Parts of the Carpel

3. Odd one — Rice
   Category of remaining — Dicotyledonous seeds

4. Odd one — Thalamus
   Category of remaining — Parts of a seed

5. Odd one — Apple
   Category of remaining — True fruits with edible part formed from the ovary

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

2. A fruit is the ripened ovary.

3. The radicle of an embryo develops into the root system.

4. Micropyle is a small pore which allows the entry of water inside the seed.

5. Enzymes act best at a temperature between 35° to 40° C.

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

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.

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:

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.

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.

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.

Differences between Hypogeal and Epigeal germination are:

1. Sepals — Sepals are located in the Calyx which is the outermost whorl of the flower.
2. Petals — Petals are located in the Corolla which is the second inner whorl of the flower.
3. Anthers — Anthers are located at the tip of the stamens in the third whorl of the flower, inner to the petals.
4. Stigma — Stigma is located in the fourth and innermost whorl of the flower, in the pistil at the tip of the style.

Difference in function between Ovary and Ovule is:

Difference in function between Petal and Sepal is:

Difference in function between Filament and Style are:

Difference in function between pollen grains and ovule are:

Diagram of Longitudinal section of a maize grain:

1. The epithilial layer divides the embryonic and endospermic region of the grain.

2. Aleurone layer is protinaceous in nature.

3. Endosperm stores food in the form of starch.

4. Radicle is the part of the seed which develops into the root.

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

1. 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

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

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

4. 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.

5. One important role of Stigma is that it receives the pollen grains during pollination.

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

2. The parts 1 to 4 are:
   1 → Epicarp
   2 → Mesocarp
   3 → Endocarp
   4 → Seed

3. Epicarp, Mesocarp, and Endocarp are collectively known as the Pericarp.

4. The ovule that contains the fertilised cell develops into a seed.

5. Mesocarp is the sweet, fleshy and edible layer.

Radicle

Reason — In germinating seed, the radicle grows downward and develops the root.

Plumule

Reason — In a germinating seed, the plumule grows upward and develops into the shoot.

Maize

Reason — Maize is a monocotyledonous seed while others are dicotyledonous seed.

Epigeal

Reason — In epigeal germination the cotyledons and the plumule comes out from the soil.

Hypogeal

Reason — In hypogeal germination only plumule comes out of the soil to form leaves.

Anther

Reason — Anther is the part of the stamen where pollen is produced.

Stamen and Carpels

Reason — Stamen is a male reproductive part and Carpel is female reproductive part of the flower.

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.

Cotyledons or Endosperm

Reason — Cotyledons or Endosperms stores nutrients which are required by the development of embryo during seedlings.

Pedicel

Reason — The floral stalk is technically termed as Pedicel.

Mesocarp

Reason — In the case of mango, the mesocarp are pulpy.

Starch

Reason — The upper larger part of the maize grain, called the endosperm stores food in the form of starch.

Both (1) and (2)

Reason — Gynoecium is made up of the carpel or the pistil.

Corolla

Reason — Corolla is made up of structures called petals. The petals make the flower attractive and hence attract insects for pollination.

Soil

Reason — Water, air, and favourable temperature are the three necessary conditions for the germination of a seed.

1. Calyx, Corolla, Androecium, and Gynoecium
2. Insects, Wind, Water, and Animals
3. Monocotyledonous seeds and Dicotyledonous seeds
4. Epigeal germination and Hypogeal germination
5. Self pollination and Cross pollination

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.

1. Pea seed
2. Maize grain
3. Bean seed
4. Papaya seed

Differences between Radicle and Plumule are:

Differences between Hilum and Micropyle are:

Differences between Testa and Tegmen are:

Two main functions of a fruit are:

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

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.

1. False
   Reason — Seeds always have cotyledons. Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.
2. 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.
3. False
   Reason — Seeds are of two types — monocotyledons having a single cotyledon and dicotyledons having two cotyledons.
4. True
   Reason — Oxygen is required to oxidize the stored food and release energy required for the growth of the embryo.

1. Radicle is the part of the seed which develops into root.
2. Cotyledons contain stored food material which is used by the seedling for growth.
3. Endosperm stores food in the form of starch.
4. Micropyle absorbs and allows the entry of as much water as is needed for germination.

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.

1. Radicle
2. Plumule

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

1. 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.

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

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

4. 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.

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