NEET Practice Questions (MCQs) with Answers & Solutions

An enzyme is composed of an apoenzyme (the protein part) and a coenzyme (the non-protein part). The apoenzyme by itself is inactive, and it requires the coenzyme to become active. Thus, the correct statement is: Coenzyme (Inactive) + Apoenzyme (Inactive) ---> Enzyme (Active).

Sucrose is hydrolyzed by the enzyme invertase. Invertase catalyzes the hydrolysis of sucrose into glucose and fructose, which are simpler sugars. This process is essential in various biological and industrial processes.

Vitamin A is a fat-soluble vitamin. Fat-soluble vitamins include vitamins A, D, E, and K. These vitamins are stored in the body's fatty tissue and liver, and they are absorbed along with fats in the diet. Unlike water-soluble vitamins (like Vitamin C and the B vitamins), fat-soluble vitamins can be stored in the body for long periods.

Hemorrhage disease, which is characterized by excessive bleeding, is caused by the deficiency of Vitamin K, also known as phylloquinone. Vitamin K is essential for the synthesis of proteins required for blood clotting. Without sufficient Vitamin K, the blood clotting process is impaired, leading to increased bleeding.

Cyanocobalamin, also known as Vitamin B12, is not synthesized from vegetables. It is primarily found in animal products such as meat, dairy, and eggs. Vitamin B12 is essential for red blood cell formation, neurological function, and DNA synthesis. Vegetarians and vegans are often advised to take B12 supplements to avoid deficiency.

Yeast is a rich source of multiple B vitamins, including B1 (thiamine), B6 (pyridoxine), and H (biotin). Therefore, the correct answer is 'all.'

Vitamin E deficiency can lead to sterility, particularly because vitamin E is crucial for reproductive health. Therefore, the correct answer is 'Sterility.'

Complete hydrolysis of nucleic acids results in the formation of pentose sugars, phosphoric acid, and nitrogen-containing heterocyclic bases. Hexose sugars are not produced in this process. Therefore, the correct answer is 'hexos sugar.'

Pyrimidine bases include cytosine (C), thymine (T), and uracil (U). Therefore, the correct answer is 'All'. Pyrimidines have a single ring structure as opposed to purines which have a double ring structure.

Thymine (T) is not present in RNA. In RNA, thymine is replaced by uracil (U). RNA is composed of adenine (A), guanine (G), cytosine (C), and uracil (U).