Mock Test-4 (Paper-1) (Question 51-100)

Total Questions: 50

41. In living cells synthesis of ribonucleic acid (RNA) takes place in :

Correct Answer: (b) Nucleus
Solution:The process of copying genetic information from one strand of the DNA into RNA is termed as transcription. It takes place in nucleus with the help of RNA polymerase.

42. Cell organelles that are involved in the waste diposal system of the cell are :

Correct Answer: (b) Lysosomes
Solution:Lysosomes are found in cytoplasm of the cell. It acts as the waste disposal system by digesting unwanted or harmful substances in the cytoplasm. Due to this act, they are known as 'suicide bags'.

43. Which one of the following functions is not carried out by smooth endoplasmic reticulum?

Correct Answer: (c) Synthesis of protein
Solution:The smooth endoplasmic reticulum (smooth ER) is continuous with the rough ER but has few or no ribosomes on its cytoplasmic surface. Functions of the smooth ER include: Synthesis of carbohydrates, lipids, and steroid hormones.

44. Vivipary in plants means

Correct Answer: (d) germination of seeds inside the fruit while it is still on the plant parent tree
Solution:Viviparous plants produce seeds that germinate before they detach from the parent plant.

45. Choose the forms in which most plants absorb nitrogen

(i) Proteins

(ii) Nitrates and Nitrites

(iii) Urea

(iv) Atmospheric nitrogen

Correct Answer: (b) (ii) and (iii)
Solution:Most plants absorb nitrogen in the form of nitrates and nitrites and urea. Atmospheric nitrogen is not available to the plants because the plants do not have enzymes to break the triple bond between the two atoms of Nitrogen.

46. If the xylem of a plant is mechanically blocked, which of the following functions of the plant will be affected?

Correct Answer: (b) Transport of water and solutes
Solution:Xylem is water conducting tissue in plants. If the Xylem of the plants is removed, upward movement of the water and transportation of solutes will stop leading to wilting of leaves and ultimately cause the death of plants.

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

List-I List-II 
A. Gonads1. Insulin
B. Pituitary2. Progesterone
C. Pancreas3. Growth hormone
D. Adrenal4. Cortisol

 

Code:ABCD
(a)2341
(b)2314
(c)3241
(d)3214
Correct Answer: (b)
Solution:Progesterone is released from the female gonads. It has roles in the female menstrual cycle, pregnancy and embryogenesis. Growth hormone or homatropine, is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals, the pituitary gland secretes this hormone.

The pancreas secretes insulin that regulates the sugar metabolism in the body. Cortisol is released from the zona fasciculata of the adrenal cortex in response to stress.

48. Excessive exposure of humans to UV-rays results in

(i) damage to immune system

(ii) damage to lungs

(iii) skin cancer

(iv) peptic ulcers

Correct Answer: (c) (i) and (iii)
Solution:Ozone layer present in stratosphere functions as a shield against high energy and harmful ultraviolet radiations. In the absence of ozone layer, the extremely harmful UV radiations will reach earth, cause large scale mutations to organisms, reducing photosynthesis, blinding of animals and humans, developing skin cancer and herpes and death of young ones.

By filtering out harmful UV radiations, ozone protects the immune system of living beings against various diseases.

49. Match the items in column-I with those in column-II, and select the correct choice:

Column-IColumn-II
A. Small poxI. Bacteria
B. CholeraII. Virus
C. MalariaIII. Deficiency of minerals
D. AnaemiaIV. Female mosquito

 

Code:ABCD
(a)IVIIIIII
(b)IIIIVIII
(c)IVIIIIII
(d)IIIIVIII
Correct Answer: (b)
Solution:Small pox is caused by 'Variola virus'. Cholera, is a bacterial disease, caused by 'Vibrio cholerae'. Malaria is a protozoan disease, caused by plasmodium and it's vector is 'Anopheles female mosquito'. Anemia is caused due to the deficiency of iron.

50. Sugarcane is one of the important cash crops in India. It is grown to obtain

Correct Answer: (d) Sucrose
Solution:The sugarcane crop is one of the most important cash crop in India. Its stem has the highest sucrose content.