Question :
11.When you learned to speak English, you may have learned : 1245539
11.When you learned to speak English, you may have learned the following saying: “When two vowels go walking, the first does the talking.” If we were to apply this rule to heterozygous genes, we would be most accurate if we said, “When two genes go walking, the ________ one does the talking.”
a.maskedc.dominant
b.recessived.typical
12.Which type of allele is ignored when found in a heterozygous gene pair?
a.maskedc.typical
b.dominantd.recessive
13.Maricella was born several days ago, and her pediatrician has observed that she has almond-shaped eyes and a fold over her eyelids. In addition, her head, neck, and nose are smaller than other babies of her birth weight. With which of the following conditions would Maricella most likely be diagnosed?
a.Down syndromec.Kleinfelter’s syndrome
b.Turner’s syndromed.Phenylketonuria
14.Maricella was born several days ago, and her pediatrician has observed that she has almond-shaped eyes and a fold over her eyelids. In addition, her head, neck, and nose are smaller than other babies of her birth weight. It is most likely that Maricella has an extra of the _____ pair of chromosomes.
a.4thc.17th
b.9thd.21st
15.Which maternal characteristic is most strongly associated with giving birth to a baby with Down syndrome?
a.low levels of intelligence in the mother
b.consumption of alcohol during pregnancy
c.higher maternal age
d.exposure to lead or mercury by the baby immediately after birth
16.Which of the following statements supports the proposition that the presence of an X chromosome appears to be necessary for life?
a.X-chromosomal genotypes are expressed as consistent phenotypes at a rate of around 85%, while Y-chromosomal genotypes are expressed as consistent phenotypes at a rate of only about 15%.
b.The X chromosomes are expressed far earlier in the prenatal period than the Y chromosomes.
c.There are no chromosomal disorders wherein a person has only Y chromosomes.
d.Most of the lethal chromosomal disorders, including Tay-Sachs disease and cystic fibrosis, are located on the Y chromosome.
17.Traits that are “either/or” phenotypes (e.g., being color blind or not being color blind, having a blood clotting disorder or not having a blood clotting disorder) are usually controlled by ________ genes.
a.polymorphicc.multiple
b.mutatedd.single
18.If a physician informed you that your speech disorder was the result of problems on chromosomes 4, 7, and 15, you would rightly conclude that the disorder is always classifiable as
a.recessive.c.dominant.
b.polygenic.d.sex-linked.
19.When many genes work together to determine a characteristic, there may be a large range of phenotypes that are expressed. Why is this?
a.Because each allele of the genes may be differently structured, leaving a large variety of outcomes.
b.Because there are many combinations of dominant and recessive genes that can lead to various levels of the characteristic being expressed.
c.Because each gene is contributed to by a different chromosome, bringing more phenotypical variety into the characteristic.
d.Because the genes all work to “cancel” each other out, leaving only one “odd” gene to express the phenotype.
20.David and Katie have always been close. In fact, they are so close that they shared the womb when their mother was pregnant with them. Given the information that you have already been given in this question, which of the following can you state conclusively?
a.David and Katie are monozygotic twins.
b.David and Katie are conjoined twins.
c.David and Katie are dizygotic twins.
d.David and Katie share 25% of their genotype.
