How do Organisms Reproduce? — Science STD 10 — Question

Describe the alimentary canal of man.

What is the difference between the chemical composition of soaps and detergents? State in brief the action of soaps in removing an oily spot from a shirt. Why are soaps not considered suitable for washing where water is hard?

Bacteria have a simpler body plan when compared with human beings. Does it mean that human beings are more evolved than bacteria? Provide a suitable explanation.

Plants absorb water from the soil. How does this water reach to the top of the tree? Explain in detail.

The human body has an organ A which acts as a double pump. The oxygenated blood coming from the lungs through a blood vessel B enters the upper left chamber C of the double pump. When chamber C contracts, then blood goes into lower left chamber D. The contraction of chamber D forces the blood to go into a blood vessel E which supplies oxygenated blood to all the organs of the body (except the lungs). The deoxygenated blood coming out of the body organs is taken by a blood vessel F to the right upper chamber G of pumping organ. Contraction of chamber G forces the deoxygenated blood into right lower chamber H. And finally the contraction of chamber H sends the deoxygenated blood into lungs through a blood vessel I.

1. What is organ A?
2. Name the blood vessel (i) B (ii) E (iii) F, and (iv) I.
3. What are chambers (i) C, and (ii) D?
4. What are chambers (i) G and (ii) H?

When water is added gradually to a white solid X, a hissing sound is heard and a lot of heat is produced forming a product Y. A suspension of Y in water is applied to the walls of a house during white washing. A clear solution of Y is also used for testing carbon dioxide gas in the laboratory.

1. What could be solid X? Write its chemical formula.
2. What could be product Y? Write its chemical formula.
3. What is the common name of the solution of Y which is used for testing carbon dioxide gas?
4. Write chemical equation of the reaction which takes place on adding water to slid X.
5. Which characteristic of chemical reactions is illustrated by this example?

Properties of the elements are given below. Where would you locate the following elements in the periodic table?

1. A soft metal stored under kerosene.
2. An element with variable (more than one) valency stored under water.
3. An element which is tetravalent and forms the basis of organic chemistry.
4. An element which is an inert gas with atomic number 2.
5. An element whose thin oxide layer is used to make other elements corrosion resistant by the process of “anodising”.

How many pairs of chromosomes are present in human beings? Out of these how many are sex chromosomes? How many types of sex chromosomes are found in human beings?
"The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it". Draw a flow chart showing determination of sex of a newborn to justify this statement.

During the respiration of an organism A, 1 molecule of glucose produces 2 ATP molecules whereas in the respiration of another organism B, 1 molecule of glucose produces 38 ATP molecules.

1. Which organism is undergoing aerobic respiration?
2. Which organism is undergoing anaerobic respiration?
3. Which type of organism, A or B, can convert glucose into alcohol?
4. Name one organism which behaves like A.
5. Name two organisms which behave like B.

State one difference between artificial kidney and natural kidney?