NEET Biology Solved Question Paper 2002

The premolars and molars are called cheek teeth. These are also called Iophodont teeth. Their free ends are flattened and bear transverse ridges to crush and grind the food.

Photorespiration is a metabolic pathway that occurs in plants in the presence of light, in which ribulose bisphosphate carboxylase/oxygenase the (RuBisCO) enzyme involved in carbon dioxide fixation with ribulose bisphosphate, accepts oxygen, in place of carbon dioxide, resulting in the formation of a twocarbon compound, glycolate. Most of the fixed carbon represented by the glycolate can be salvaged by a series of reactions-the glycolate pathway involving the peroxisomes and mitochondria, and returned to the chloroplasts. However, some of the carbon is lost as carbon dioxide. Unlike respiration there is no production of ATP.

In frog, all nerve cells connecting to central nervous system (brain and spinal cord) with receptor and effectors constitute the peripheral nervous system. Some small masses of nerve cell bodies are called ganglia. They develop from neural crest cells in frog.

The bud dormancy is induced by adantscissic acid (ABA). The level of endogenous ABA increases with the onset of dormant period and decreases when it is broken.

Ambulacral grooves are found in the arms of echinoderms lined by tube feet. Ambulacral grooves are absent in Ophiuroidea which are covered by ossicles.

Bile is an alkaline viscous fluid, yellow to green in colour and having a pH of 7.8- 8.6.

Saliva is secreted by salivary gland and its pH is about 6.8.

Gastric juice is secreted by the gastric gland in stomach and its pH value is 1- 2.5.

Pancreatic juice is colourless watery fluid and slightly alkaline. Its pH is 7.5-8.0.

Therefore, gastric juice has minimum pH value.

In the process of glycolysis, one molecule of hexose sugar, i.e. glucose or fructose, a 6C-compound is splitted to form two molecules of a 3C- compound, pyruvic acid (CH₃COCOOH).

In cockroach, excretion is mainly performed by one or two pairs of malpighian tubules. One of this pair opens into the middle region of intestine and other pair of coxal glands are located in prosoma and opens at bases of fifth walking legs.

Glycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor). Glyeoproteins are formed in the lumen of rough endoplasmic reticulum, but may subsequently be modified in the lumen of the Golgi apparatus, where other amino acids of the protein may become glycosylated.

A telocentric chromosome'scentromere is located at the terminal end of thechromosome. A telocentric chromosome has therefore only one arm.