Tag: science & technology

Chlorophyll is the green pigment in plants that absorbs light for photosynthesis. Tendrils are climbing organs, stomata are pores for gas exchange, and starch is a carbohydrate storage product.

Quinine is a traditional treatment for malaria. It's extracted from cinchona bark and has antimalarial properties. It doesn't cure pimples, typhoid, or AIDS.

The cheetah is NOT extinct (it's endangered), while the dodo, brontosaurus, and mammoth are all extinct species. The question asks which is 'not extinct'.

Quinine is obtained from the bark of the cinchona tree, native to South America. Eucalyptus, redwood, and bunyan trees don't produce quinine.

Crop rotation maintains soil fertility by alternating different crops to prevent nutrient depletion and break pest cycles. Regular tilling can harm soil structure, growing the same crop repeatedly depletes specific nutrients, and irrigation alone doesn't maintain fertility.

The normal resting heart rate for a healthy adult ranges from 60-100 beats per minute, with 72 bpm being the commonly cited average. This is a standard physiological baseline used in medical assessments.

Tree age is most accurately determined through dendrochronology - counting the annual growth rings visible in a cross-section of the trunk. Each ring represents one year of growth, with light and dark bands showing seasonal variations.

Aves is the biological classification (class) that includes all bird species. Birds are characterized by feathers, beaked jaws, hard-shelled eggs, and high metabolic rates, distinguishing them from other vertebrates.

In biological classification, "Pisces" is the Latin term for the fish class. Fish are aquatic vertebrates with gills and fins, while reptiles, mammals, and birds belong to entirely different classes.

An average human adult has 32 permanent teeth, including 8 incisors, 4 canines, 8 premolars, and 12 molars (including 4 wisdom teeth). Children have 20 primary teeth that are eventually replaced by permanent teeth.