486: In human being, normaly in which one of the following parts, does the a sperm fertilize the ovum?
(a) Fallopian
(b) Cervix
(c) Upper part of uterus
(d) Lower part of uterus
Explanation:
Once a month a single mature ovum is produced and leaves the ovary in a process called 'ovulation'. This ovum enters a tube leading to the uterus called 'fallopian tube'. The ovum needs to meet up with the sperm in the fallopian tube if fertilization is to occur.
487: Assertion (A): All proteins in our food are digested in small intestine only.
Reason (R): The protein-digesting enzymes from pancreas are released into small intestine.
(a) Both A and R are individually true and R is the correct explanation of A.
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false.
(d) A is false but R is true.
Explanation:
Protein digestion begins in the stomach. In acidic medium of gastric juice, the protein digesting enzyme, 'pepsin' breaks down proteins into peptones. In small intestine 'trypsin' acts on peptones to form peptides and amino acids.
488: Which one of the following is present in the largest amount in terms of per cent by mass in the earth's crust ?
(a) Silicon
(b) Oxygen
(c) Carbon
(d) Calcium
Explanation:
Oxygen, in the form of oxides, is present in the largest amounts, second abundant is Silicon, third abundant is Aluminium, in the earth's crust.
489: With reference to pre-packaged items in India, it is mandatory to the manufacturer to put which of the following information on the main label, as per the Food Safety and Standards (Packaging and Labelling) Regulations, 2011?
1. List of ingredients including additives
2. Nutrition information
3. Recommendations, if any, made by the medical profession about the possibility of any allergic reactions
4. Vegetarian/non-vegetarian
Select the correct answer using the code given below.
(a) 1, 2 and 3
(b) 2, 3 and 4
(c) 1, 2 and 4
(d) 1 and 4 only
490: Which one of the following parts of human brain is the regulating centre for swallowing and vomiting?
(a) Pons
(b) Medulla oblongata
(c) Cerebrum
(d) Cerebellum
Explanation:
Medulla Oblongata is long, stalk like lowermost portion of the brain stem which is involved regulating the functions of swallowing and vomiting.