Answer: C) Decomposers are those organisms that recycle matter in the ecosystem.. Explanation: Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition.   The statement "Decomposers are those organisms that recycle matter in the ecosystem" describes decomposers.

Answer: C) < 85 db Explanation: Sound intensity or level is measured by a unit called a decibel. An 85 decibel noise level is not a safe standard for the public.   Hence, Acceptable noise level for human ear is less than 85 db.

Answer: C) 7:5 Explanation: Milk in 1-litre mixture of A = 4/7 litre.  Milk in 1-litre mixture of B = 2/5 litre.  Milk in 1-litre mixture of C = 1/2 litre.   By rule of alligation we have required ratio X:Y       X                  :                 Y     4/7                                2/5              \                      /               (Mean ratio)                   (1/2)             /                      \  (1/2 – 2/5)     :       (4/7 – 1/2)       1/10                      1/1 4    So Required ratio = X : Y = 1/10 : 1/14 = 7:5

Water is capable of dissolving a variety of different substances, which is why it is such a good solvent. And, water is called the "universal solvent" because it dissolves more substances than any other liquid It means that wherever water goes, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients

Answer: C) 22 nd March Explanation:

Answer: D) Rs. 960 Explanation: Let C.P. = Rs. C. Then, 832 - C = C - 4482C = 1280 => C = 640Required S.P. = 150% of Rs. 640 = 150/100 x 640 = Rs. 960.

Answer: A) 23 Explanation: 23 chromosomes are in a human gamete. Human somatic cells have 46 chromosomes(23 pairs) but a gamete(germ cell) gets half the amount, i.e. 23 chromosomes, (one from each pair). There will be half the number of chromosomes an organism has in its somatic cells (all other body cells except gametes).   For example in humans, the somatic cells contain 46 chromosomes which are the diploid number (2n) and each sperm and egg has 23 chromosomes where one of them is the sex chromosome.

Answer: A) TRUE Explanation: True, Air is a Mixture. Air is considered as mixture for the following reasons ; 1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air. 2. Air shows the properties of all the gases present in the atmosphere. For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion. 3. Air does not have a fixed formula. 4. Air has a variable composition because air at different places contains different amount of gases. 5. Heat or Light energy is neither absorbed nor released when air is prepared physical by mixing required amount of gases . 6. Mixture does have fixed boiling Point. It holds good in case of liquid air.