Exam 2 Fall 17 Flashcards
True or False:
Mitosis takes place in your gametes, whereas meiosis takes place in your somatic cells.
F
True or False:
An X chromosome is an autosome.
F
True or False:
Alleles are described as alternate versions of a gene.
T
True or False:
Sister chromatids are joined at the telomere.
f
True or False:
Differentiation of the zygote into a multicellular organism results from selective gene expression.
t
True or False:
Skin cells contain information about skin color but not about muscle proteins
f
True or False:
Mutations in DNA can lead to new alleles.
t
True or False:
The process by which the genotype is expressed as phenotype is known as gene expression
t
True or False:
The phenotype always shows the recessive allele.
f
True or False:
Proto-oncogenes are normal genes with the potential to become oncogenes.
t
An example of nondisjunction is when:
A) homologous chromosomes fail to separate during meiosis
B) DNA fails to replicate before meiosis
C) a cell does not go through cytokinesis
D) meiosis stops after the first cell division
a
A woman with type A blood has a child with type O blood. What is the woman’s genotype? A. IBi B. IAi C. Ii D. IAIA E. IAIB
b
Mature human nerve cells and muscle cells
A. become cancerous more easily than other cell types.
B. continue to divide throughout their lifetime.
C. are permanently in a state of nondivision.
D. cease dividing after a predetermined number of cell generations.
c
Which of the following shows the greatest promise as a cancer chemotherapy agent?
A. a drug that interferes with cellular respiration
B. a drug that prevents mitotic spindle from forming
C. a drug that prevents crossing over
D. a drug that prevents tetrad formation
b
Meiosis results in 2^n possible chromosomal combinations in humans. How many chromosomal combinations are possible for gametes formed by meiosis in humans?
a) 46
b) 2,116
c) 46,604
d) 8,388,608
d
Cystic fibrosis in humans is caused by mutations in a single gene and is inherited as an autosomal (non-sex-chromosome) recessive trait. A normal couple has two children. The first child has cystic fibrosis, and the second child is unaffected. What is the probability that the second child is a carrier (heterozygous) for the mutation that causes the disease?
A. 1/4 or 25% B. 1/2 or 50% C. 2/3 or 67% D. 3/4 or 75% E. 1 or 100%
c