Biology

The cerebellum is responsible for coordinating balance and precision in movements, making it the correct answer. Other brain parts like the cerebrum, thalamus, and medulla oblongata have different primary functions.

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.

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.

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

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

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

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 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.

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 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.