Zoology MCQs for NEET — Practice Questions with Answers

Nucleoside on hydrolysis yields nitrogen bases (purine, pyrimidine) and pentose sugar (ribose, deoxyribose)

Base pairs occur when nitrogenous bases make hydrogen bonds with each other. Each base has a specific partner: guanine with cytosine, adenine with thymine (in DNA) or adenine with uracil (in RNA)

Enzymes speed up the rate of reaction by lowering the activation energy required for the reaction to proceed. They do this by providing an alternative reaction pathway with a lower activation energy. This does not change the equilibrium of the reaction, but it allows the reaction to reach equilibrium faster.

The Km value (Michaelis constant) is used to compare the catalytic efficiency of different enzymes. It represents the substrate concentration at which the reaction rate is half of its maximum value (Vmax). A lower Km value indicates higher affinity of the enzyme for the substrate, meaning the enzyme is more efficient at lower substrate concentrations.

Mitochondria are known as the powerhouse of the cell because they are rich in catabolic enzymes. These enzymes are involved in the breakdown of molecules to produce energy in the form of ATP through cellular respiration.

Cytochromes are proteins that play a key role in the electron transport chain, which is a series of complexes that transfer electrons from electron donors to electron acceptors via redox reactions. This process is essential for the production of ATP in cellular respiration.

Amylase is an enzyme that catalyzes the hydrolysis of starch into sugars, primarily maltose. It is present in saliva and pancreatic juice and helps in the digestion of dietary starches.

Due to use of agrochemicals fertiliser and pesticide the yield during green revolution was immense. 

A genetically modified organism (GMO) is an organism whose genetic material has been altered using genetic engineering techniques. This allows for the introduction of new traits or characteristics that are not naturally found in the organism. GMOs are widely used in agriculture to enhance crop yield, resistance to pests, and adaptability to environmental conditions.

The full form of GMO is Genetically Modified Organism. This term refers to organisms whose genetic material has been artificially manipulated through genetic engineering. The modification is typically done to achieve desired traits such as increased resistance to pests, improved nutritional content, or greater tolerance to environmental stress.