Flower & Its Parts, Parts of Flower, Fertilization, Parts of Plants, Types of Pollination

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Flower & Its Parts

The flower is the reproductive part of the plant. It is mainly concerned with formation of seeds. It is regarded as the modified shoot for the purpose of reproduction.

Parts of Flower

  • A typical flower consists of a short axis known as the thalamus, on which floral leaves are inserted in four distinct whorls, which are as under:

    • Calyx

    • Corolla

    • Androecium

    • Gynaecium

  • Calyx: Calyx is the outermost whorl of floral leaves called sepals. The sepals can be defined as the green and leaf like structures which are mainly concerned with the protective function.

  • Corolla: Corolla is the second whorl of floral leaves called petals. The petals are beautifully coloured which are responsible for the attraction to the insects towards them.

  • Androecium: The third whorl of the leaves consists of stamens. It is considered as the male part of the flower.

  • Gynaecium: Gynaecium is the inner most whorl of the floral leaves called carpels. It is considered as the female part of the flower.

Parts of Plants

  • Ginger: Modified Stem (rhizome) and it is also a root.

  • Cinnamon: Bark of stem

  • Radish: Root

  • Potato: Stem (tuber)

  • Peanut: Seed

  • Saffron: Stigma/flower

  • Almond: Fruit

  • Chillies: Fruit

  • Spinach: Leaves

  • Tomato: Fruit

  • Turnip: Root

  • Carrot: Root

  • Cucumber: Fruit

Photosynthesis

Definition: Photosynthesis is a process in which plants manufacture their food (simple carbohydrates) in the presence of chlorophyll and sunlight by the combination of carbon dioxide and water.

Raw Material for Photosynthesis

  • Carbon dioxide: Taken from air

  • Water: Absorbed by roots from soil

  • Sunlight: From Sun

  • Chlorophyll: green pigment present in leaves

By-Products of Photosynthesis

  • Carbohydrates (simple sugar): used by plants as a food material and excess of it is converted into starch

  • Oxygen: Released into air

Importance of Photosynthesis

  • Major process of food production in plants

  • Utilization of of the atmosphere and liberation of oxygen

  • Important in reducing of the atmosphere which is dangerous for the human beings as well as animal health.

Pollination

It is the process by which seeds are produced.

Definition:

Pollination is the phenomenon of transfer of pollen from male reproductive organ (anther) to female reproductive organ (stigma) in flowering plants through biological or physical agency.

Types of Pollination

There are two types of Pollination

  • Self-Pollination: In this type of pollination pollens are transferred to the stigma in the same flower. Some plants are by nature self-pollinated as wheat and grasses.

  • Cross Pollination: In this type the pollen grains are transferred from the anther of one flower to the stigma of another flower. The cross pollination is considered and advantageous to the plant as the seeds produced by cross-pollination are usually greater in number and the plant germinated from them are superior in vigour, height and weight.

Vehicles for Pollination

Vehicles for pollination are animals, water, wind and insects. Therefore cross pollination may be:

  • Entomophily-by insects

  • Anemophily-by wind

  • Hydrophily-by water

  • Zoophily-by animals

Importance of Pollination

  • Vital process for reproduction in plants

  • Reproduction is carried out by reproductory organs of plants due to pollination

Fertilization

The fusion of male and female gametes is called fertilization.

Types of Fertilization: Following are the major types of fertilization:

  • External Fertilization

  • Internal Fertilization

  • Self-Fertilization

  • Cross-Fertilization

External Fertilization

  • This type of fertilization is generally observed I simple aquatic animals.

  • In such animals both ova and sperms are released into the water where fertilization occurs.

  • In terms of evolution external fertilization is of primitive type and is not better biologically as compared to internal fertilization.

  • Internal Fertilization:

  • In the internal fertilization the females keep ova inside their bodies and males deposit sperms within the tube of reproductive tacts of females.

  • For all land animals internal fertilization is almost must because sperms are quickly killed by dehydration.

  • In terms of evolution internal fertilization is highly evolved and much better biologically as compared to external fertilization.

Self-Fertilization

  • Self-fertilization occurs within the same animal.

  • It is that fertilization in which sperms are used by the ovaries of same animal e.g. Tapeworm

Cross-Fertilization

Cross-fertilization is the process in which sperms of one animal are transferred into the body of another animal e.g. Earthworm.

Genetic Engineering

The deliberate modification of the characteristics of an organism by manipulating its genetic material.

OR

Scientific alteration of the structure of genetic material in a living organism. It involves the production and use of recombinant DNA and has been employed to create bacteria that synthesize insulin and other human proteins.

Significance of Genetic Engineering

  • To cure the genetic disorders Heredity diseases can possibly be treated by this technique by transplanting normal genes in the place of abnormal or diseased genes.

  • To Prepare Better Crops with desired characteristics could possibly be produced by introducing desired genes.

  • To Get Better Breeds of Animals Like plants better breeds of animals can also be produced by the introduction of recombinant DNA.

  • Interferon Interferons are effectively used in the treatment of Hepatitis of A & B.

  • Insulin Human insulin is being produced by genetic engineering to treat diabetes

  • Vaccines Genetic engineering has also helped in the production of vaccines which are used for controlling and treating viral diseases.