Biology

Thrombosis is the formation of a blood clot inside a blood vessel, which can obstruct the flow of blood. This matches the description of 'clotting of blood vessels.'

The Ishihara test is a widely used color perception test specifically designed to detect red-green color deficiencies. The other options are unrelated to color vision testing.

Insulin lowers blood glucose levels by facilitating cellular uptake of glucose, whereas carbohydrates, cholesterol, and epinephrine can raise blood glucose levels. Therefore, insulin is the exception in this list.

The ibex is a wild mountain goat species found in the Himalayas and other alpine regions. It is not a dog, hen, or sheep, making 'Goat' the correct answer.

The spleen is known as the 'graveyard of RBCs' because it is the primary organ where old and damaged red blood cells are removed and destroyed.

Leukaemia is a disease characterized by an abnormal and excessive increase in white blood cells (WBCs). This overproduction disrupts normal blood cell function, leading to various health problems. The other options do not involve increased WBCs.

The human skull is composed of 22 bones, including the cranial and facial bones. This is a well-established anatomical fact.

Grebes have legs positioned far back on their bodies, which makes them excellent swimmers but awkward or unable to walk on land effectively. Hummingbirds, on the other hand, can walk or hop short distances. Therefore, the correct answer is Grebes.

Reproduction is essential for the continuation and survival of species because it allows organisms to produce offspring and pass on their genetic material to the next generation. Without reproduction, a species would eventually become extinct.

The normal pH range of human blood is tightly regulated between 7.35 and 7.45, which is slightly alkaline. This range is essential for proper physiological functions. Options A, B, and D fall outside this normal range.

Proteins are polymers made up of amino acid monomers linked together by peptide bonds, forming polypeptides. Therefore, the correct answer is 'Polypeptide'.

Aldosterone is a hormone produced by the adrenal glands that regulates sodium and potassium levels in the blood by promoting sodium retention and potassium excretion in the kidneys. Cortisol primarily regulates metabolism and stress response, glycogens are storage forms of glucose, and pheromones are chemical signals for communication, not involved in electrolyte balance.

Each human hand contains 27 bones: 8 carpal bones in the wrist, 5 metacarpal bones in the palm, and 14 phalanges in the fingers (3 in each finger and 2 in the thumb). This is confirmed by authoritative sources such as the National Institutes of Health and medical anatomy references. Therefore, the correct answer is 27 bones, which corresponds to option B.

The correct term for the framework made up of all the bones in the body is the 'skeleton'. It provides structure and support to the body.

The human body has approximately 600 to 650 muscles, but the exact number varies depending on classification. None of the given options (632, 639, 642) are universally accepted as precise counts, so 'None of these' is the best choice.

Scientific studies show that gold is present in trace amounts throughout the human body, with the liver and bone marrow each containing about 25% of the total body gold, and skin and bone each about 20%. Among keratin-rich tissues, nails (including toenails) have been found to contain higher trace amounts of gold compared to skin, liver, or kidney. This is because gold can accumulate in keratinous tissues like nails. Although the amounts are extremely small, toenails have higher gold content relative to the other listed body parts, making option C (Toenails) the correct answer.

The Goldcrest weighs about 4.5 to 7 grams, which is more than a US penny (about 2.5 grams). The Weebill weighs about 6 grams, also more than a penny. Hummingbirds vary widely in weight, but the smallest species, the bee hummingbird, weighs about 2 grams, which is less than a penny. Therefore, the correct answer is C, Hummingbird, as it is the only bird among the options that weighs less than a penny.

Pomology is the branch of botany that studies and cultivates fruit. The other options refer to different fields: Plriculture is not a standard term, Sericulture is the cultivation of silkworms, and Apiculture is beekeeping.

The largest cell in the human body is the ovum (egg cell), which is much larger than red blood cells, sperm cells, or neurons. The ovum is visible to the naked eye, unlike the other cells listed.

A cataract is a clouding of the lens in the eye, which leads to a decrease in vision. Therefore, it is a disease of the eyes.

The stomach is typically described as having a J shape, which resembles a bag-like structure that connects the esophagus to the small intestine.

The hypothalamus controls the pituitary gland by producing hormones that regulate its secretion, making it the key brain region responsible for pituitary function.

Leprosy is caused by the bacterium Mycobacterium leprae, making bacteria the correct microorganism responsible for this ancient disease.

Saliva of a healthy human is slightly alkaline, typically with a pH around 6.5 to 7.5, which helps neutralize acids and maintain oral health.

Chromosomes are composed primarily of DNA and proteins (mainly histones). The DNA carries genetic information, while the proteins help in packaging and regulating the DNA structure.