AP Biology Genetics
, Which of the following is true about a plant with the genotype AABbcc? - CORRECT
ANSWERS-It is homozygous at two loci.
Details: An organism having a pair of identical alleles at a given locus is said to be
homozygous for that locus. Here, the plant is homozygous at loci A and C.
What is an allele? - CORRECT ANSWERS-an alternative version of a gene
Details: A diploid organism carries two alleles for each autosomal gene. The two alleles
are found at comparable locations (loci) on homologous chromosomes. The alleles may
be identical or slightly different, but they affect the same genetic character.
You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered
one. All of the F1 are pink. What does this say about the parental traits? - CORRECT
ANSWERS-Red shows incomplete dominance over white, and the F1 is therefore pink.
Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant
disorder. Which statement below must be true? - CORRECT ANSWERS-It is very likely
that at least one of Woody Guthrie's parents also have had the allele for Huntington's
disease.
Details: Unless the disease is caused by a new mutation, which is quite rare, individuals
with a dominant condition must have inherited the dominant allele from one of their
parents. As it happens, Guthrie's mother also died of Huntington's disease.
Various procedures can be used to detect genetic disorders before birth. Among the
tests discussed in this chapter, which is the least invasive (list first), and which two allow
the chromosomes of the fetus to be examined? - CORRECT ANSWERS-ultrasound
imaging ... chorionic villus sampling ... amniocentesis
Details: Both CVS and amniocentesis involve the preparation of a karyotype using fetal
cells.
Which of the following do you expect if an individual is heterozygous for the sickle-cell
trait? - CORRECT ANSWERS-He or she will show some symptoms of the disease.
Details: A heterozygote will produce both normal and abnormal hemoglobin.
How do cells acquire homologous chromosome pairs that carry the alleles that are
independently assorted? - CORRECT ANSWERS-Fusion of gametes.
Details: During fertilization, gametes bring together homologous chromosomes to
generate a diploid individual.
Which of the following statements most accurately describes the process of
independent assortment? - CORRECT ANSWERS-Alleles of different genes segregate
from one another in a random manner.
Details: The random distribution of alleles is required for independent assortment.
, Which of the following is true about a plant with the genotype AABbcc? - CORRECT
ANSWERS-It is homozygous at two loci.
Details: An organism having a pair of identical alleles at a given locus is said to be
homozygous for that locus. Here, the plant is homozygous at loci A and C.
What is an allele? - CORRECT ANSWERS-an alternative version of a gene
Details: A diploid organism carries two alleles for each autosomal gene. The two alleles
are found at comparable locations (loci) on homologous chromosomes. The alleles may
be identical or slightly different, but they affect the same genetic character.
You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered
one. All of the F1 are pink. What does this say about the parental traits? - CORRECT
ANSWERS-Red shows incomplete dominance over white, and the F1 is therefore pink.
Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant
disorder. Which statement below must be true? - CORRECT ANSWERS-It is very likely
that at least one of Woody Guthrie's parents also have had the allele for Huntington's
disease.
Details: Unless the disease is caused by a new mutation, which is quite rare, individuals
with a dominant condition must have inherited the dominant allele from one of their
parents. As it happens, Guthrie's mother also died of Huntington's disease.
Various procedures can be used to detect genetic disorders before birth. Among the
tests discussed in this chapter, which is the least invasive (list first), and which two allow
the chromosomes of the fetus to be examined? - CORRECT ANSWERS-ultrasound
imaging ... chorionic villus sampling ... amniocentesis
Details: Both CVS and amniocentesis involve the preparation of a karyotype using fetal
cells.
Which of the following do you expect if an individual is heterozygous for the sickle-cell
trait? - CORRECT ANSWERS-He or she will show some symptoms of the disease.
Details: A heterozygote will produce both normal and abnormal hemoglobin.
How do cells acquire homologous chromosome pairs that carry the alleles that are
independently assorted? - CORRECT ANSWERS-Fusion of gametes.
Details: During fertilization, gametes bring together homologous chromosomes to
generate a diploid individual.
Which of the following statements most accurately describes the process of
independent assortment? - CORRECT ANSWERS-Alleles of different genes segregate
from one another in a random manner.
Details: The random distribution of alleles is required for independent assortment.
