Life Process

Question 1

reproduction (types)

Answer 1

reproduction is a biological process in which living beings produce their own kinds asexually or sexually.

• asexual reproduction
• sexual reproduction

Question 2

asexual and sexual reproduction (types)

Answer 2

asexual reproduction is a reproduction which takes place without the help of fusion of a male gamete and a female gamete. types: fission, budding, sporulation, fragmentation, regeneration, vegetative propagation.

the method of reproduction ehich takes place by the fusion of a male gamete and female gamete is called sexual reproduction.

Question 3

fission ( types)

Answer 3

A fission is the method of asexual reproduction in which a unicellualr organism divides into two or more daughter organisms.

binary fision: The method of asexual reproduction in which one unicellular organism divides into two daughter organisms is called a binary fission.

Multiple fission
The method of asexual reproduction in which one unicellular organism divides into more than two daughter organisms is called a multiple fission.

Question 4

budding, sporulation, fragmentation, regeneration, vegetative propagation ( examples)

Answer 4

budding: The method of asexual reproduction which
takes place with the help of a bud is called
budding. Plants like yeast and animals like
hydra reproduce asexually.
sporulation: The method of asexual reproduction which takes place by means of spores is called
sporulation. This method is common in mucor, marchantia, moss, mushroom, fern,
etc.
fragmentation:A fragmentation is the method of asexual reproduction in which a multicellular organism splits into two or more fragments and each fragment develops into a new organism. Spirogyra.
regeneration: A regeneration is the method of asexual
reproduction in which each fragment of an organism regains its lost body parts and develops into a complete organism. example: planaria, starfish.
vegetative propagation: A vegetative propagation is the method of asexual reproduction in which new
plants are produced by vegetative parts like roots, stem and leaf.
root: dahlia, sweet potato
stem: potato, rose
leaf: begonia, bryophyllum

Question 5

advantages of asexual reproduction

Answer 5

1. It is an easy and a fast method of reproduction.
2. Only one organism can reproduce by this method.
3. The offspring produced by this method are genetically identical to their parents.
4. The plants which do not produce viable seeds like potato, rose, sugarcane,
   etc. can easily be propagated by this method.

Question 6

sexual reproduction in plants and animals

Answer 6

Most flowering plants reproduce sexually by means of seeds. A flower is the sexually reproductive part of
flowering plants.anther produces pollen grains and ovary produces female gametes. The anthers begin to dry and burst open releasing pollen grains.This process is called pollination. It may be self-pollination and cross-pollination. After pollination, fertilization, i.e. fusion of male gamete and female gamete, takes place
which forms a zygote. After fertilization, the ovule develops into seed and ovary into the fruit. The seed grows into a new plant on favourable condition.

Vertebrate animals reproduce sexually by means of gametes. However, invertebrates like arthropods, molluscs, annelids, round worms, flatworms, etc. reproduce by sexual method. Male organisms produce male gametes and female organisms produce female gametes. On favourable condition, fusion of a male gamete and female gamete takes place to form a zygote.In animals, fertilization is of two types, i.e. external fertilization and internal fertilization.

Question 7

advantages of sexual reproduction

Answer 7

1. It gives continuity to the generations of a species.
2. It brings out variation among the members of the same species.
3. It helps in evolution of organisms.

Question 8

circulatory system

Answer 8

The system formed by heart, blood and blood vessels which transports various
materials from one part of the body to another is called the blood circulatory system.

Question 9

blood, plasma (functions )

Answer 9

The blood is a red fluid connective tissue. It consists of plasma (55%) and blood corpuscles (45%).

A plasma is a straw-coloured liquid which occupies 55% of the blood volume. It contains about 90% water,
8% proteins and 2% other dissolved substances.

Functions of plasma
1. It transports digested food and hormones to different parts of the body.
2. It transports waste materials like urea, carbon dioxide, etc. for their removal
from the body.
3. It regulates body temperature and amount of water and minerals in the body.

Question 10

rbc & wbc

Answer 10

The red blood cells or erythrocytes are red-coloured blood cells having biconcave shape.

The white blood cells (leucocytes) are colourless with irregular blood cells having a nucleus.

Question 11

platelets

Answer 11

The platelets or thrombocytes are colourless, oval or round blood cells without nucleus.

Question 12

heart

Answer 12

The heart is a powerful and hollow organ made of cardiac muscle. It is conical in shape and is about the size of the fist of the individual. The heart is located near the middle of the thoracic cavity between two lungs.

Question 13

blood vessels (arteries, veins& capillaries)

Answer 13

The muscular tubes or pipes through which blood flows are called blood vessels.
Arteries: The thick-walled blood vessels that carry blood away from the heart are called arteries.
Veins: The thin-walled blood vessels that carry blood towards the heart are called veins.
capillaries: The capillaries are extremely narrow and microscopic blood vessels.

Question 14

photosynthesis

Answer 14

The process of making food by green
plants in the presence of sunlight is called
photosynthesis.