Mock Test-5 (Paper-1) (Question 51-100)

Total Questions: 50

31. Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?

Correct Answer: (b) Carbon, hydrogen, nitrogen
Solution:Carbon, hydrogen and nitrogen were primarily responsible for the origin of life on the earth. It is believed that organic molecules could be formed by inorganic process under primitive earth conditions. The gases present on the earth like Carbon, Hydrogen and Nitrogen might have combined in favourable conditions provided by the primitive earth to produce amino acids and other organic molecules like sugars, nucleic acids bases and lipids. these molecules are called building blocks of life.

32. Metalloids are

Correct Answer: (c) elements having some properties of both metals and non-metals.
Solution:A metalloid is a chemical element with properties in between, or that are a mixture of, those of metals and non-metals. There is no standard definition of a metalloid, nor is there complete agreement as to which elements are appropriately classified as such.

The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. Elements less commonly recognised as metalloids include carbon, aluminium, selenium, polonium, and astatine.

33. Match List-I with List-II and select the correct answer from the codes given below:

List-I List-II 
A. Potassium bromide1. Fertiliser
B. Potassium nitrate2. Photography
C. Potassium sulphate3. Bakery
D. Monopotassium4. Gunpowder tartarate

 

Code:ABCD
(a)2413
(b)2431
(c)3231
(d)4213
Correct Answer: (a)
Solution:Potassium bromide is used in photography as a restrainer in black and white developer formulas.

Gun powder, also called black powder, is a mixture of sulphur, charcoal, and potassium nitrate. Gun powder can be made by just using potassium nitrate and charcoal (or alternatively without charcoal), but without the sulphur (or coal), the powder is not as strong.

Potassium sulfate is primarily used as a fertilizer. Mono potassium tartrate is used in bakery by combination with baking soda it results in to evolution of CO² which is used for baking cakes.

34. Which one of the following substances is used in the manufacture of safety matches?

Correct Answer: (a) Red phosphorus
Solution:Red phosphorus is mostly used in the manufacture of safety matches and in making smoke bombs.

35. Polycot is a mixture of

Correct Answer: (c) polyester and cotton
Solution:Polycot is a blend of polyester and cotton. They are blended for advantages of both cotton and polyester fabric into one fabric.

36. The major constituent of connective tissue is -

Correct Answer: (d) Collagen
Solution:Connective tissues are the most diverse and widely distributed tissues in the body. Bone, types of blood are well-known connective tissues which perform many different functions and constitute different properties. Collagen fibres, fibroblasts and other components form important constituent of connective tissues.

37. Which one of the following is the bioethically non controversial source of stem cells as an alternative to the highly controversial embryonic stem cells?

Correct Answer: (a) Bone marrow - derived stem cells
Solution:Stem cells are of two types- (i) Embryonic stem cells and (ii) Adult stem cell. Embryonic stem cells are obtained from embryo at the time of the earliest stage of the development of embryo. These embryos could be develop either in uterus or in test tubes.

The Embryonic stem cells are responsible for the development of the organs like brain, Heart, muscles etc. The adult stem cells are found in the bone marrow Muscles and brain where the replace the damaged cells and produces new cells.

38. Which of the following is a chemical change?

A. Bubbling of oxygen gas through water.
B. Burning of wax of a candle.
C. Emitting of light from an electric bulb on passing electric current.
D. Passing of carbon dioxide gas through lime water.

Correct Answer: (c) B and D
Solution:Burning of candle wax and passing CO₂ through lime water are chemical changes and are irreversible. In both those changes new products are formed. Burning of candle wax results into formation of CO₂ and CO₂ on passing through lime solution forms CaCO₃.
CO₂ + Ca(OH)₂ → CaCO₃ + H₂O

39. Lysosome arises from

Correct Answer: (b) golgi apparatus
Solution:Lysosomal membrane is formed in ER, later it is modified and transferred to the cis face of Golgi apparatus where further processing releases lysosome.

40. pH of human blood is

Correct Answer: (a) 7.4
Solution:pH of human blood is 7.4