41. ____ being a higher category, is the assemblage of families which exhibit a few similar characters:
[A] Class
[B] Species
[C] Genus
[D] Order
Show Answer
Correct Answer: D [Order]
Notes:
Order is an assemblage of families which exhibit a few similar characters. The similar characters are less in number as compared to different genera included in a family. A class includes one or more orders.
42. Which of the following bacterium causes crown gall disease in plants?
[A] Agrobacterium tumefaciens
[B] Pseudomonas fluorescens
[C] Bacillus thurigiensis
[D] None of the above
Show Answer
Correct Answer: A [Agrobacterium tumefaciens]
Notes:
Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die. In science of Biotechnology, it is considered as natural engineer.
43. Animal protein is called first class protein because it is _____:
[A] Rich in essential amino acids
[B] d
Delicious in taste
[C] Cheaper in the market
[D] Easily digestible
Show Answer
Correct Answer: A [Rich in essential amino acids]
Notes:
Proteins from animals are called ‘first class’ proteins – they provide all the essential amino acids, including those that the body can’t make. Proteins from plants are ‘second class’ proteins.
44. In a food chain, the solar energy utilized by plants is only ____:
[A] 10 per cent
[B] 1 per cent
[C] 0.1 per cent
[D] 0.01 per cent
Show Answer
Correct Answer: C [0.1 per cent]
Notes:
Plants, on average, capture only about 0.1 0.4 percent of the solar energy reaching Earth. However, it does not mean that the rest is a “vast untapped reservoir” awaiting man’s exploitation. All biological systems, including crops, follow the second law of thermodynamics when solar energy (a high-energy form) is converted into chemical energy. Plants utilize this chemical energy in the process of building their own tissue.
45. In cauliflower plant the useful part is ___:
[A] Young inflorescence
[B] Underground stem
[C] Leaves
[D] Root
Show Answer
Correct Answer: A [Young inflorescence]
Notes:
Cauliflowers are characterized mainly by a inflorescence composed of numerous undeveloped flowers that gather around a central axis. Cauliflower and broccoli are grown for their large, edible, very young inflorescence.
46. Root Hairs arise from _____:
[A] Cortex
[B] Pericycle
[C] Epidermis
[D] Endodermis
Show Answer
Correct Answer: C [Epidermis]
Notes:
Root hairs are tubular-shaped tip-growing cells that arise from epidermal cells known as trichoblasts, behind the tips of young roots. Like all tip-growing cells, root hairs grow by the addition of cell wall precursors to the tip delivered by vesicles from the endomembrane system.
47. Which of the following carry the blood from all parts of body back to the heart?
[A] White Blood Cells
[B] Veins
[C] Arteries
[D] Platelets
Show Answer
Correct Answer: B [Veins]
Notes:
A vein is an elastic blood vessel that transports blood from various regions of the body to the heart. Veins are components of the cardiovascular system, which circulates blood to provide nutrients to the cells of the body. Veins can be categorized into four main types: pulmonary, systemic, superficial, and deep veins.
48. The rhythmic contraction of the lining of muscles of canal to push the food along the gut is called _____:
[A] Peristalsis
[B] Facilitation
[C] Guttation
[D] None of the above
Show Answer
Correct Answer: A [Peristalsis]
Notes:
Peristalsis is the wave of rhythmical contraction, which takes place in the alimentary canal. It is produced by involuntary contraction of circular muscles, which is preceded by a simultaneous contraction of the longitudinal muscle, and relaxation of the circular muscle lining the gut. Peristalsis pushes the food through the alimentary canal.
49. What is the shape of the two guard cells which enclose stomata?
[A] Oval
[B] Triangular
[C] Rectangular
[D] Kidney shaped
Show Answer
Correct Answer: D [Kidney shaped]
Notes:
Stomata are structures present in the epidermis of leaves that regulate the process of transpiration and gaseous exchange. Each stoma is composed of two kidney bean-shaped cells known as guard cells which enclose stomatal pore. The guard cells possess chloroplasts which are absent in other epidermal cells.
50. Water stomata are present in the _____:
[A] Leaf margin
[B] Veins
[C] Ventral surface of Leaf
[D] Dorsal surface of Leaf
Show Answer
Correct Answer: A [Leaf margin]
Notes:
Water stomata, also known as hydathodes, are structurally modified portions of leaf which are meant to send out excess amount of water in liquid form. They are present usually at the rip or margins of leaves of those plants that grow in moist places. They secrete water through pores in the epidermis or leaf margin, typically at the tip of a marginal tooth or serration. Hydathodes are commonly seen in water lettuce, water hyacinth, rose, balsam, etc.
