What is metamorphosis? Give examples.
A change in the animal’s body structure through the cell growth and the differentiation by which an animal develops after birth or hatching is known as metamorphosis. Or, we can say transforming of larva into an adult through a biological process is called as metamorphosis. Metamorphosis involved the sudden and abrupt changes in the structure of an animal. For example: frogs, insects etc.
Life cycle of Frog:
It involves mainly three stages:
Egg → Tadpole → Adult
From the egg tadpole emerges which have gills, tail and a small circular mouth. Tadpole can swim in water freely. Now some sudden and abrupt changes occurs in the structure of tadpole and it develops into a mature frog. The process of metamorphosis starts with the development and finally tail appearance occurs by the body.
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?
Differentiate between internal fertilization and external fertilization.
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 ?
Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?
Fill in the blanks :
(a) Fossil fuels are , and .
(b) Process of separation of different constituents from petroleum is called .
(c) Least polluting fuel for vehicle is .
Does pure water conduct electricity? If not, what can we do to make it conducting?
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
The process that you saw in Activity 14.7 is used for purification of copper. A thin plate of pure copper and a thick rod of impure copper are used as electrodes. Copper from impure rod is sought to be transfered to the thin copper plate. Which electrode should be attached to the positive terminal of battery and why?
Match items in column A with one or more items in column B:
A B
(i) Inner planets (a) Saturn
(ii) Outer planets (b) Pole Star
(iii) Constellation (c) Great Bear
(iv) Satellite of the Earth (d) Moon
(e) Earth
(f) Orion
(g) Mars
Mark ‘T’ if the statement is true and ‘F’ if it is false.
(a) Generally non-metals react with acids. ( )
(b) Sodium is a very reactive metal. ( )
(c) Copper displaces zinc from zinc sulphate solution. ( )
(d) Coal can be drawn into wires. ( )
Make sketches of animal and plant cells. State three differences between them.
The following Table shows the total power shortage in India from 1991– 1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.
Give two examples of each.
(a) Kharif crop
(b) Rabi crop