front 1 A female infant is born with several hundred oocytes, each one genetically unique. This is due to ______. | back 1 independent assortment and random crossover |
front 2 If we are to consider the variation resulting only from independent assortment and random fertilization, any resulting offspring represents about one out of ______. | back 2 72 trillion zygotes possible |
front 3 The number of gamete types from independent assortment of the homologues during meiosis in humans would be: | back 3 223 (78 million) |
front 4 Those characteristics that can be determined on superficial inspection of an individual are known as ________. | back 4 phenotypic |
front 5 Recessive genes are usually expressed in humans only when _______. | back 5 both alleles are exactly the same, or homozygous |
front 6 Dominant alleles are so called because under most circumstances they ______. | back 6 suppress the expression of other alleles |
front 7 Two alleles expressing exactly the same information for a trait are designated as _______. | back 7 homozygous |
front 8 Which of the following is true concerning environmental influence on genetic expression? | back 8 Drugs and nutrition can alter normal gene expression |
front 9 Mitosis differs from meiosis because in meiosis we observe _____. | back 9 tetrads |
front 10 An example of multiple allele inheritance is ___________. | back 10 the ABO blood group |
front 11 The reason recessive genetic disorders are more frequent than disorders inherited as dominant is that _____________. | back 11 carriers may pass them on to their offspring, unaware that they are carriers |
front 12 The gene responsible for the condition known as sickle-cell anemia demonstrates _______________. | back 12 incomplete dominance |
front 13 Sex chromosomes of a normal male are _______. | back 13 XY |
front 14 A chromosomal aberration in which part of a chromosome is lost is known as ______________. | back 14 deletion |
front 15 Inheritance of stature (height) in humans is probably due to ______. | back 15 polygene inheritance |
front 16 A woman has blond hair and brown eyes. This statement is best described as indicating ___________________. | back 16 phenotype |
front 17 An individual who is heterozygous for a particular trait, yet expresses both alleles of that trait, is an example of _____________. | back 17 incomplete dominance |
front 18 Huntington's disease is an example of a(n) ___________ gene. | back 18 delayed-action |
front 19 ___________ is the most common type of fetal testing. | back 19 Amniocentesis |
front 20 Huntington's disease involves ________. | back 20 degeneration of the basal nuclei of the brain |
front 21 Amy's hand was exposed to X rays. A gene in a skin cell of her hand mutated. This mutant gene ____________. | back 21 will replicate itself when the cell divides but will not be passed on to Amy's offspring |
front 22 The diploid genome contains chromosomes from ___________. | back 22 both the mother and father, but only about half of the genome from each |
front 23 The main way a recessive allele would be expressed even when only one copy is present would be _____. | back 23 sex-linked inheritance |
front 24 A couple whose blood types are A (IAi) and B (IBi) may have a child with which of the following blood types? | back 24 A, B, AB, and O |
front 25 Gene mutations in the sex chromosomes of the human would tend to become visibly expressed ____________. | back 25 more frequently in males |
front 26 One possible scientific explanation for siblings having very different skin color is _____________. | back 26 polygene inheritance, which results in continuous phenotypic variation between extremes |
front 27 Which of the following statements is true concerning screening? | back 27 Screening can be done before conception by carrier recognition or during fetal testing. |
front 28 Select the incorrect statement about Chromosomes and genes. | back 28 Genes on neighboring but different chromosomes are called linked. |