Differentiate between internal fertilization and external fertilization.
Internal fertilization |
External fertilization |
Fusion of male and female gametes that takes place inside the body is known as internal fertilization. |
Fusion of male and female gametes that takes place outside the body is known as external fertilization. |
In this, they give birth to the young ones directly. |
In this, the organisms first lay down eggs and then they take care of them till the time of hatching at the particular place and after the hatching, the young ones arrive. |
It occurs in animals that includes cows, hens, dogs and includes mammals also. |
It occurs in aquatic animals like frog, fish, starfish etc. |
What is metamorphosis? Give examples.
Define asexual reproduction. Describe two methods of asexual reproduction in animals.
How are test tube babies born?
Complete the cross-word puzzle using the hints given below
Across
1. The process of the fusion of the gametes.
6. The type of fertilization in hen.
7. The term used for bulges observed on the sides of the body of Hydra.
8. Eggs are produced here.
Down
2. Sperms are produced in these male reproductive organs.
3. Another term for the fertilized egg.
4. These animals lay eggs.
5. A type of fission in amoeba.
How are babies produced through IVF technique? What are such babies called?
Describe the process of fertilization in human beings.
Give two difference between a zygote and a foetus.
In which female reproductive organ does the embryo get embedded?
How is an embryo developed?
Explain the importance of reproduction in organisms.
Which of the following can be beaten into thin sheets?
(a) Zinc (b) Phosphorus (c) Sulphur (d) Oxygen
Fill in the blanks
(a) Most liquids that conduct electricity are solutions of , ______________ and ______________.
(b) The passage of an electric current through a solution causes ______________ effects.
(c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the terminal of the battery.
(d) The process of depositing a layer ofany desired metal on another material by means of electricity is called .
Give two examples each of situations in which you push or pull to change the state of motion of objects.
Fill in the blanks:
(a) Friction opposes the _____________ between the surfaces in contact with each other.
(b) Friction depends on the _____________ of surfaces. (c) Friction produces __________.
(d) Sprinkling of powder on the carrom board ________ friction.
(e) Sliding friction is ___________ than the static friction.
List conditions under which combustion can take place.
Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)
Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.
Fill in the blanks:
(a) A place where animals are protected in their natural habitat is called .
(b) Species found only in a particular area is known as .
(c) Migratory birds fly to far away places because of changes.
Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.
What are the different ways in which water gets contaminated ?
Explain why sportsmen use shoes with spikes.
Does pure water conduct electricity? If not, what can we do to make it conducting?
Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.
Suggest three measures to protect ourselves from lightning.
Explain the difference between the thermoplastic and thermosetting plastics.
Angle of incidence is equal to the angle of reflection
(a) Always (b) Sometimes
(c) Under special conditions (d) Never
Explain why chloroplasts are found only in plant cells?
Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the Earth covers only a part of moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
Boojho made the following sketch (Fig. 17.29) of the solar system. Is the sketch correct? If not, correct it.
The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accomodate?