A Space Probe Discovers a Planet Inhabited by Creatures That

question 64

Essay

A space probe discovers a planet inhabited by creatures that reproduce with the same hereditary patterns seen in humans. Three phenotypic characters are height (T = tall, t = dwarf), head appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures are not "intelligent," Earth scientists are able to do some controlled breeding experiments, using various heterozygotes in testcrosses. For tall heterozygotes with antennae, the offspring are: tall-antennae, 46; dwarf-antennae, 7; dwarf-no antennae, 42; tall-no antennae, 5. For heterozygotes with antennae and an upturned snout, the offspring are: antennae-upturned snout, 47; antennae-downturned snout, 2; no antennae-downturned snout, 48; no antennae-upturned snout, 3. Calculate the recombination frequencies for both experiments.

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Definitions:

Nebulizer Treatment

The delivery of medication in the form of a mist inhaled into the lungs, typically used for treating asthma, COPD, and other respiratory conditions.

Expiratory Wheezes

High-pitched sounds heard with a stethoscope during exhalation, indicating obstruction or narrowing of the lower airways, often associated with conditions like asthma.

Impaired Gas Exchange

A condition in which there is an obstruction in the transfer of oxygen from the lungs to the blood, often leading to decreased oxygenation.

Pneumonia

An inflammatory condition of the lung affecting primarily the small air sacs known as alveoli, typically caused by infection.