Bio Exam 3
The gene for a certain sex-linked trait is found only on the Y chromosome. If the male parent has this gene, the trait will be expressed in
100 percent of the male offspring
Humans have ________ pairs of homologous chromosomes.
23
If a female who carries the X-linked recessive gene for hemophilia mates with a male who does not have hemophilia, what is the chance that their daughter will be a carrier of the gene?
50 percent
If a plant has a total of 18 chromosomes, how many chromosomes would be present in each of its gametes?
9
If a genetic disorder is caused by a dominant allele, individuals with which of the following genotypes would be affected by the disorder?
AA and Aa
Because an individual with an XX genotype is a female, is an individual with an XO (no second sex chromosome) a male?
No, because the Y chromosome contains the gene that makes an embryo male.
What is the significance of crossing over?
The resulting gametes will have novel gene combinations compared to their parent cells' gene combinations.
Humans have ________ pairs of homologous chromosomes.
XY
Which term is best associated with a synapsed pair of homologous chromosomes?
a tetrad
The processes of mitosis, meiosis, and binary fission all
are used to produce daughter cells.
Which of the following pairs of processes encompasses the entire cell cycle?
cell division and interphase
If two different alleles for the same trait have an equal effect on the phenotype, the alleles are
codominant
Homologous chromosomes
consist of a maternal and paternal copy of each chromosome.
The X chromosome in humans is
found as a pair in females
The possible combinations of alleles in gametes ________ due to independent assortment and crossing over.
increases
A pool of cells is treated with a chemical that halts progress through the cell cycle. In which stage of the cell cycle would most cells be found?
interphase
When Mendel proposed the law of segregation, which of the following pieces of information did he NOT have?
knowledge of the location of the alleles for flower color
Chromosomes are lined up at the middle of the cell during the ________ portion of cell division.
metaphase
Which of the following genetic changes would NOT be passed from parent to child?
mutation in a skin cell
During meiosis I, the chromosome number is reduced to haploid by separating
one of each homologous chromosome pair into two different daughter cells.
A ________ is a chart that shows genetic relationships within a family over several generations.
pedigree
In humans, X-linked genetic diseases
tend to be expressed more in males than in females.
In Mendel's controlled mating experiments, the individuals produced by crossing two true-breeding parents are referred to as
the F 1 generation.
The difference between the alleles of a single gene is
their DNA base sequence
If two parents are heterozygous for an autosomal recessive disease,
they are both considered genetic carriers for the disease.
If a female who carries the X-linked recessive gene for hemophilia mates with a male who does not have hemophilia, what is the chance that their daughter will be a carrier of the gene?
traits are passed from one generation to the next.
The successful union of one male and one female gamete forms a new single cell known as a
zygote
