Biology

291. Blood group AB has –

1. No antigen
2. No antibody
3. Neither antigen nor antibody
4. Both antigen and antibody

Option “2” is correct
Group AB has both A and B antigens on red cells (but neither A nor B antibody in the plasma).
292. Which Vitamins are those, if taken in excess can be dangerous as they are stored in the body?

1. B Complex
2. E and C
3. B and C
4. A and D

Option “4” is correct
In large amounts certain vitamins can be toxic, leading to a condition called vitamin toxicity or vitamin poisoning. Excess vitamin D accumulates in the liver and can cause bone calcification, headaches, weakness, nausea, vomiting, constipation, kidney stones and frequent thirst and urination. Accumulation of Vitamin A causes Toxicity in vitamin A is known as hypervitaminosis A.
293. An instrument for measuring blood pressure is called –

1. Barometer
2. Spirometer
3. Sphygmomanometer
4. Haemocytometer

Option “3” is correct
Sphygmomanometer is an instrument for measuring blood pressure.
294. The vitamin most readily destroyed by heat is –

1. Riboflavin
2. Ascorbic acid
3. Tocopherol
4. Thiamine

Option “2” is correct
Vitamin C also known as Ascorbic acid is easily destroyed by excessive heat and water, as well as exposure to air.
295. Rickets is the deficiency disease of vitamin-D, in which the affected part is the –

1. Skin
2. Hair
3. Bone
4. Blood

Option “3” is correct
Rickets is a bone disease that affects infants and young children. The child’s growing bones fail to develop properly due to a lack of vitamin D. This can result in soft and weakened bones, fractures, bone and muscle pain, and bony deformities.
296. In a majority of flowering plants, out of the four megaspores, what is the ratio of functional and degenerate megaspores?

1. 2:2
2. 1:3
3. 3:1
4. 4:0

Option “2” is correct
A megaspore mother cell, or megasporocyte, is a diploid cell in plants in which meiosis will occur, resulting in the production of four haploidmegaspores. At least one of the spores develop into haploid female gametophytes thus making the ratio of functional and degenerate megaspores is 1:3.
297. Which among the following is also called as ‘power house of the cell’?

1. Plastids
2. Mitochondria
3. Golgi bodies
4. Cell wall

Option “2” is correct
The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular metabolism. This process is known as cellular respiration. It is for this reason that mitochondria are often referred to as the powerhouses of the cell.
298. What is the role of Pneumatophores?

1. Protect plant from animals
2. Get oxygen for respiration
3. Supports plant in standing upright
4. Helps plant for pollination

Option “2” is correct
Pneumatophores are spongy erect roots extending above the surface of the water that facilitate the exchange of oxygen and carbon dioxide for the roots. Produced by a plant growing in water, pneumatophores are specialized root structures (above-ground spongy outgrowths of roots) that grow out from the water surface where inadequate oxygen required for normal respiration of the roots is present.
299. Which blood group is universal donor?

1. A
2. O
3. B
4. AB

Option “2” is correct
The blood groups O+ and O- are universal donors. The only difference is in the recipients to whom the blood is transfused; O+ can be transfused to any positive blood groups, whereas O- is transfused to both positive as well as negative blood groups.
300. Potato, tomato and brinjal are three different species but all belong to which genus?

1. Solanum
2. Panthera
3. Felis
4. Tigris

Option “1” is correct
Solanum is a large and diverse genus of flowering plants, which include food crops of high economic importance, the potato, brinjal and the tomato.