Tag: science & technology

For a child to have blood type A when the mother is blood type B, the father must contribute an A allele. If the father is blood type AB, his genotype is AB, meaning he can pass either an A or B allele to the child. When he passes the A allele and the mother (who could be genotype BO) passes her O allele, the child would have blood type A (genotype AO). This is the only option among the choices that guarantees the father can contribute an A allele.

Charles's Law states that the volume of a gas is directly proportional to its absolute temperature (in Kelvin) when pressure is held constant. This relationship is expressed mathematically as V1/T1 = V2/T2, where V represents volume and T represents absolute temperature. Option A incorrectly inverts the ratio, option B is the Ideal Gas Law (not Charles's Law), and option D incorrectly swaps the temperature and volume subscripts.

A year on Saturn (the time it takes to complete one orbit around the Sun) is approximately 29.5 Earth years. This is because Saturn is much farther from the Sun than Earth and follows a larger orbital path according to Kepler's laws of planetary motion. The other options (256.9, 168.3, and 16.8) do not match the actual orbital period of Saturn.

Pluto has a diameter of approximately 2,376 km, while Earth's diameter is about 12,742 km. By volume, approximately 500 Plutos would fit inside one Earth (Earth's volume is roughly 500 times greater than Pluto's). This makes option C (500) the correct answer. Options A (200), B (300), and D (457) don't match the actual volume ratio between Earth and Pluto.

Perspiration (sweating) is the body's primary cooling mechanism. When sweat evaporates from the skin surface, it absorbs heat energy from the body, causing a cooling effect. This process is called evaporative cooling. Respiration is for gas exchange (oxygen/carbon dioxide), mastication is chewing, and urination is waste excretion - none of these primarily function in temperature regulation like perspiration does.

Gramineae is the scientific family name for grasses, which includes wheat, rice, corn, bamboo, and lawn grasses. This is one of the largest plant families and consists of monocotyledonous plants with hollow stems and narrow leaves. The everyday common name for plants in the Gramineae family is indeed 'grasses.' Options B (nuts), C (pulses), and D (legumes) refer to different plant families.

After pollination, the flower's ovary develops into a fruit that contains and protects the seeds. This is a fundamental part of the plant reproductive cycle. Thorns are defensive structures, leaves are for photosynthesis, and branches provide structural support - none of these form specifically as a result of pollination.

Quinine is a traditional antimalarial medication extracted from the bark of the cinchona tree. It has been used for centuries to treat malaria by killing the Plasmodium parasites that cause the disease. AIDS is caused by HIV and requires antiretroviral therapy, while typhoid is a bacterial infection treated with antibiotics.

Crop rotation involves growing different crops in succession on the same land to prevent nutrient depletion and break pest/disease cycles. This maintains soil fertility naturally. Regular tilling can actually harm soil structure, repeatedly growing the same crop depletes specific nutrients, and irrigation provides water but does not maintain fertility.

Quinine is extracted from the bark of the cinchona tree native to South America. The cinchona bark has been the primary commercial source of quinine for malaria treatment since the 17th century. Redwood and eucalyptus are not sources of medicinal quinine.