Biology

391. To reduce tooth decay most toothpastes contain a –

1. Bromide
2. Fluoride
3. Iodide
4. Chloride

Option “2” is correct
Fluoride in toothpastes prevent tooth decay from progressing and can even reverse, or stop, early tooth decay.
392. Which part of the plant gives us saffron?

1. Roots
2. Petals
3. Stem
4. Stigma

Option “4” is correct
Saffron is a spice derived from the flower of Crocus sativus, commonly known as the “saffroncrocus”. The vivid crimson stigmas and styles, called threads, are collected and dried to be used mainly as a seasoning and colouring agent in food.
393. Consider the following plant hormones:
1.Gibberellins-Seed germination
2.Auxins-Apical dominance
3.Cytokinins-Climacteric ripening of fruits
Which among the above is/are correctly paired with their respective functions in plant physiology?1. Only 1
2. 1 and 2
3. 2 and 3
4. 1, 2 and 3
Option “2” is correct
Cytokinins or CKs are a group of chemicals that influence cell division and shoot formation. Ethylene is related with the Climacteric ripening of fruits.
394. Which among the following has segmented body?

1. Phylum Mollusca
2. Phylum Arthopoda
3. Phylum Annelida
4. Phylum Coelenterata

Option “3” is correct

The annelids also known as the ringed worms or segmented worms, are a large phylum. The basic annelid form consists of multiple segments. Each segment has the same sets of organs and, in most polychates, has a pair of parapodia that many species use for locomotion.

395. Which of the following are longest cells of human body?

1. Pancreatic cells
2. Epethelial cells
3. Nerve cells
4. Epidermal cells

Option “3” is correct
The longest cells in the human body are nerve cells. The longest cells in the human body are the nerve cells whose cell bodies are located in the base of spinal cord and whose axons run down to the ends of toes.
396. Which of the following is responsible for giving colour to human skin?

1. Luciferin
2. Haemoglobin
3. Flavonoids
4. Melanin

Option “4” is correct
Skin color is due primarily to the presence of a pigment called melanin, which is controlled by at least 6 genes. Both light and dark complexioned people have melanin. However, two forms are produced-pheomelanin, which is red to yellow incolor, and eumelanin , which is dark brown to black.
397. The smallest known prokaryotic organism is –

1. Microcystis
2. Mycoplasma
3. Bacteria
4. Chlorella

Option “2” is correct
Mycoplasma genitalium, a parasitic bacterium which lives in the primate bladder, waste disposal organs, genital, and respiratory tracts, is thought to be the smallest known organism capable of independent growth and reproduction.
398. Which is the gland that holds the body’s temperature?

1. Pineal
2. Pituitary
3. Hypothalamus
4. None of these

Option “3” is correct
Hypothalamus control the body temperature.
399. The hotness or pungency of chilli pepper is due to?

1. Cucumin
2. Sorbitol
3. Argenol
4. Capsaicin

Option “4” is correct
A substance called capsaicin gives chillies their distinctive hot, peppery taste. The chemical stimulates areas of the skin and tongue that normally sense heat and pain, fooling the brain into thinking they are burning.
400. Which of the following is a fungal disease?

1. Ringworm
2. Mumps
3. Rabies
4. Malaria

Option “1” is correct
Ringworm of the skin (tinea corporis) is most commonly caused by the fungus Trichophyton rubrum, which spreads from one person to another. It can also becaused by Microsporum canis, which is spread by cats and dogs.