Phloem in gymnosperms lacks :

• Sieve tubes only

• Companion cells only

• Both sieve tubes and companion cells

• Albuminous cells and sieve cells

Cells in G₀ phase :

• enter the cell cycle

• suspend the cell cycle

• terminate the cell cycle

• exit the cell cycle

Which of the following muscular disorders is inherited?

• Muscular dystrophy

• Myasthenia gravis

• Botulism

• Tetany

Select the correct option.

• 11^th and 12^th pairs of ribs are connected to the sternum with the help of hyaline cartilage.

• Each rib is a flat thin bone and all the ribs are connected dorsally to the thoracic vertebrae and ventrally to the sternum.

• There are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs.

• 8^th, 9^th and 10^th pairs of ribs articulate directly with the sternum.

Which of the following statements is correct?

• Cornea consists of dense connective tissue of elastin and can repair itself.

• Cornea is convex, transparent layer which is highly vascularised.

• Cornea consists of dense matrix of collagen and is the most sensitive portion the eye.

• Cornea is an external, transparent and protective proteinacious covering of the eye-ball.

Use of an artificial kidney during hemodialysis may result in :

(a) Nitrogenous waste build-up in the body

(b) Non-elimination of excess potassium ions

(c) Reduced absorption of calcium ions from gastro-intestinal tract

(d) Reduced RBC production

Which of the following options is the most appropriate?

• (b) and (c) are correct

• (c) and (d) are correct

• (a) and (d) are correct

• (a) and (b) are correct

Which of the following statements is incorrect?

• Viruses are obligate parasites.

• Infective constituent in viruses is the protein coat.

• Prions consist of abnormally folded proteins.

• Viroids lack a protein coat.

Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder causing wheezing due to

• inflammation of bronchi and bronchioles

• proliferation of fibrous tissues and damage of the alveolar walls

• reduction in the secretion of surfactants by pneumocytes.

• benign growth on mucous lining of nasal cavity

Which of the statements given below is not true about formation of Annual Rings in trees?

• Differential activity of cambium causes light and dark bands of tissue early and late wood respectively.

• Activity of cambium depends upon variation in climate.

• Annual rings are not prominent in trees of temperate region.

• Annual ring is a combination of spring wood and autumn wood produced in a year

What is the direction of movement of sugars in phloem?

• Upward

• Downward

• Bi-directional

• Non-multidirectional