The primary advantage of sexual reproduction is:
It maintains the chromosome number for the species.
It is necessary to protect against the effects of natural selection.
It creates diploid gametes that are clones of the parent.
It enhances genetic variation for the species.
None of the above are correct.
Which type of change in chromosome structure is most likely to be detrimental?
Deletions.
Inversions
molecular genetics.
Duplications
Translocations
Which of the following best describes the term genetic variation?
Differences in inherited traits within individuals of a population.
The changing of the genetic makeup of a population over time.
The basic unit of heredity.
The characteristics of an organism.
The effect of the environment on the expression of a trait.
The DNA sequence recognized by an endonuclease is called a(n) ____________.
Ligation site
Insertion site
Cleavage site
Restriction site
None of the above
The basic unit of heredity is called the _____________.
protein
trait
gene
enzyme
nucleotide
Which of the following methods of calculating probability is used if the order of a specific number of events occurring in the total is not important?
Chi square test
Binomial expansion
Product rule
Sum rule
None of the above
Which of the following is the most likely explanation for a high rate of crossing-over between two genes?
The two genes are far apart on the same chromosome.
The two genes are both located near the centromere.
The two genes are sex-linked.
The two genes code for similar proteins.
The two genes are on different chromosomes.
In a Chi square test of a genetic cross there are n different phenotypic classes in the offspring. What is the value for the degrees of freedom for the test?
n
n - 1
n + 1
n2
None of the above
If an organism contains two identical alleles for the same trait, it is said to be which of the following?
Cross-fertilized
Heterozygous
Homozygous
A hybrid
None of the above
A testcross is always conducted between an individual whose genotype is unknown and which of the following?
A heterozygous individual
A homozygous dominant individual
A homozygous recessive individual
Any of the above will work
None of the above
A reciprocal cross is used to determine which of the following?
If a trait is autosomal or sex-linked
The number of autosomal chromosomes
The dominant /recessive nature of a trait
The sex of the organism
None of the above
Genetic drift refers to changes in allele frequencies in a population due to _________.
Stabilization.
Random fluctuations.
Demes.
All of the above.
None of the above.
Bacteria reproduce by ___________.
Mitosis
Meiosis
Binary fission
Reductive division
All of the above
In which of the following is the male of the species the homogametic sex?
X-Y system
Z-W system
X-O system
Haplodiploid system
The male is never homogametic
What happens during the denaturation step of PCR?
The DNA nucleotides are broken apart.
The DNA returns to its natural form.
The primers bind to the target DNA sequence.
The double-stranded DNA is separated into two single DNA strands
None of the above
Which of the following statements is NOT true about genomic imprinting?
It is re-established in germ cells
It is established during embryogenesis
It is permanent in germ cells
It is maintained in somatic cells
None of the above
Coat colour in rabbits and human blood groups are both examples of ____________.
multiple allele systems
epistatic interactions
gene dosage
simple Mendelian inheritance
incomplete dominance
Which process may be used in gene mapping?
Transformation
Transduction
Conjugation
A and B
B and C
A trait that is only expressed on the sex chromosome is known as _________.
temperature-sensitive alleles
sex-influenced inheritance
sex-linked inheritance
X-linked inheritance
none of the above
Positive interference on a chromosome is best defined as:
The repression of recombination during mitosis.
The inhibition of one crossover event by a previous crossover in the region.
The statistical determination of linkage
The rate of recombination between two genes
The prevention of separation during meiosis.
Single-stranded unpaired DNA extensions formed by endonucleases upon cleavage are known as _______________.
Sticky ends.
Blunt ends
Flush ends.
Cut ends
Dead ends.
When testing for linkage using a chi-square analysis, what should be the hypothesis?
That the traits are linked.
That the traits are assorting independently.
That each trait is located near the centromere.
That all mutations produce the same phenotype.
That you always assort with a 1:1:1:1 ratio.
The synaptonemal complex is formed during ____________.
Leptotene
Prophase II
Telophase I
Prophase I
None of the above
One map unit is equal to which of the following?
100 nucleotides
1% of the chromosome
1% mutation rate
1% recombination rate
None of the above
In which of the following do the bacteria have to be in physical contact for gene transfer to occur?
Transduction
Transformation
Lysogenic cycle
Complementation
Conjugation
The transfer of genetic material between two different species is called __________.
vertical gene transfer
horizontal gene transfer
conjugation
sexual reproduction
All of the above
What two mechanisms are responsible for the development of Trisomy 21?
Translocation and duplication
Inversion and nondisjunction
Duplication and nondisjunction
Inversion and duplication
Translocation and nondisjunction
Embryonic stem cells (ESC) are ______________.
totipotent
multipotent
unipotent
pluripotent
none of the above
A human XXXY cell would contain how many Barr bodies?
0
1
2
3
4
mtDNA and cpDNA is associated with the study of _________ inheritance.
extranuclear
epigenetic
Mendelian
Darwinian
Nuclear