Chat with AIExam 2: C: Genetic Bases of Child Development
Why are African Canadians more likely to inherit sickle-cell disease?
(37) 
VerifiedAfrican Canadians are more likely to inherit sickle-cell disease because the sickle cell has a benefit: Individuals with this allele are more resistant to malaria. Therefore, in parts of the world (such as Africa) where malaria is found you are also more likely to find individuals carrying this trait. Having two alleles for sickle-cell disease has devastating consequences to the carrier. However, having only one sickle cell allele results in a person who is more resistant to malaria and yet suffers from the disorder only when put under extreme conditions (in instances of low oxygen). Therefore, having sickle-cell trait is quite adaptive in Africa. However, it has no adaptive value in Canada and accordingly we are seeing fewer and fewer individuals with sickle-cell trait in successive generations of African Canadians.
Explain basic concepts of single gene inheritance using the terms alleles, chromosomes, homozygous, heterozygous, dominant, recessive.
(32) VerifiedA good answer will include the following key points:
∙Genes come in different forms called alleles.
∙The alleles in a pair of chromosomes are sometimes the same, which makes them homozygous.
∙The alleles in a pair of chromosomes sometimes differ, which makes them heterozygous.
∙If a person is homozygous for a trait, such as eye colour, the genotype produces the phenotype.
∙If a person is heterozygous for a trait, the phenotype produced depends on which allele is dominant.
∙If one allele is dominant, its chemical instructions are followed whereas those of the other, the recessive allele, are ignored.
Describe phenylketonuria. What is it, its causes, its symptoms, and treatment?
(40) VerifiedA good answer will be similar to the following:
Phenylketonuria (PKU) is a disorder in which babies are born lacking an important enzyme. It is caused by two recessive alleles found on chromosome 12. The missing enzyme is one that breaks down phenylalanine, an amino acid. Without the enzyme, phenylalanine accumulates, damaging the nervous system and leading to delayed mental development. PKU can be controlled by diet by avoiding products that contain phenylalanine. With a special diet, mental retardation can be avoided.
Name and describe (a) a disorder caused by an abnormal number of autosomal chromosomes, and (b) a disorder caused by an abnormal number of sex chromosomes.
(33) The other day I heard someone say "There is no such thing as twins who are brother/sisters (mix-sex twins)." What would you have said if you had been there?
(39) Name and briefly describe some common disorders associated with recessive alleles.
(39) Explain how (a) twin studies and (b) adoption studies are used to determine the influence of heredity on a trait and discuss a potential flaw of each type of study.
(38) Explain what is meant by a reaction range and give an example of how a reaction range might work.
(34) You and a friend were talking about the role of heredity and environment and your friend said, "Heredity is destiny. When someone inherits genes for bad diseases there is nothing about the environment that can change the negative effects." What can you tell your friend about the interaction of heredity and environment in cases such as those involving individuals with phenylketonuria?
(33) Your friends Shania and Ricky are expecting a baby. Both Shania and Ricky are farsighted and have cheek dimples. Shania and Ricky have said that they hope that their baby won't need to wear glasses or have cheek dimples because they both hate their glasses and dimples. What can you tell them about genetic inheritance and the likelihood that they will get their wish?
(31) 
Filters
- Essay(0)
- Multiple Choice(0)
- Short Answer(0)
- True False(0)
- Matching(0)