GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles.
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Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause death of the embryo.
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Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce.
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The presence of a dominant lethal allele causes sterility.
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Detailed explanation-1: -Which of the following statements best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders? The males phenotype results entirely from his single X-linked gene.
Detailed explanation-2: -Dominant lethal alleles are very rare because, as you might expect, the allele only lasts one generation and is not transmitted. However, just as the recessive lethal allele might not immediately manifest the phenotype of death, dominant lethal alleles also might not be expressed until adulthood.
Detailed explanation-3: -Dominant lethals Alleles that need only be present in one copy in an organism to be fatal are referred to as dominant lethal alleles. These alleles are not commonly found in populations because they usually result in the death of an organism before it can transmit its lethal allele on to its offspring.
Detailed explanation-4: -Explain why disorders caused by dominant alleles on autosomes are less common than those caused by recessive alleles on autosomes? because there are also carriers and if the disorder was dominant Kt would be more common. Describe his the expression of sex-linked genes can differ between males and females.
Detailed explanation-5: -Most lethal genes are recessive. Examples of diseases caused by recessive lethal alleles are cystic fibrosis, Tay-Sachs disease, sickle-cell anemia, and brachydactyly.