Nseb

Which of the following animals has blood as circulating medium? 

(a) Cockroach 

(b) Mussel 

(c) Leech 

(d) Planaria

Which of the following is a large single-celled organism?

(a) Vorticella (b) Volvox (c) Acetabularia (d) Chlamydomonas

A biochemist prepared a mixture of all reactants and enzymes he thought were needed for DNA replication. When DNA was added, replication occurred. The product, however, consisted of the parent DNA strand paired with several DNA segments, each segment, a few hundred nucleotides long. Which of the following could possibly be missing in the reaction mixture?

(a) DNA polymerase. 

(b) RNA primers. 

(c) DNA ligase. 

(d) Single strand binding proteins

Eastern and Western Meadow Larks look almost the same and inhabit the same areas of Prairie. They recognize mates of their own species by distinctive courtship songs: This is an example of type of pre-zygotic isolation. 

(a) Ecological 

(b) gametic 

(c) mechanical 

(d) behavioural

The gas transfer system found in Aves is represented in following figures: (Bold arrows represent blood flow while thin arrows represent air flow through respiratory stem.) 

The correct representation is in the figure:

A student designs an experiment to check whether rats have UV vision. 

Design I: Food is kept in a closed room with only UV light and rat is let in. The rat goes towards the food. 

Design II. A wooden model of predator is kept in closed rooms with only UV light and rat is let in. The rat tries to run away. 

Design III. A female rat is kept in closed room with only UV light and male rat is let in. The male rat chases the female. 

Which of the above experiments can conclusively give information about the rat’s vision in UV spectrum? 

(a) Design I only 

(b) Design II only 

(c) Design I and II only 

(d) Design I, II and III

If a tissue is consuming 50 molecules of O₂ and releasing 70 molecules of CO₂, then the substrate being utilized in cellular respiration is : 

(a) glucose 

(b) fatty acid 

(c) amino acid 

(d) organic acid

Which of the following statements about human disorders caused by different organelles is true? 

(a) Peroxisomal disorders are due to mutations in nuclear genes. 

(b) Mitochondrial disorders are always due to mutations in maternally inherited mitochondrial genes. 

(c) Person can suffer from lysosomal storage diseases even if lysosomal hydrolases are synthesized in sufficient quantities. 

(d) Inefficient recycling of long chain fatty acids is likely to be a result of mitochondrial disorder.

Though both starch and cellulose are composed of repeating glucose units, the main difference between them is that: 

(a) they are bonded by 1-6 and 1-4 glycosidic linkages respectively. 

(b) they differ in the α and  β configuration. 

(c) most of the fruits and grains are rich in starch and poor in cellulose or fiber. 

(d) starch is made of simple sugars while cellulose is made of amino sugars.

Which of the following processes requires energy? 

(a) Movement of calcium into a cell. 

(b) Secretion of mucus by a cell 

(c) Entry of oxygen into a cell. 

(d) Water absorption by a cell.