Question 1

An individual that is homozygous at the locus that determines ABO blood type may have any of the following EXCEPT type _______ blood.

Accepted Answer

AB blood type results from having one A allele and one B allele, which is not possible in an individual who is homozyous at the ABO locus.

Question 2

The expression of polygenic traits is:

Accepted Answer

Polygenic traits are determined by genes at several loci, meaning that multiple genes contribute to the expression of the trait. Environmental factors can also play a role in the expression of these traits, but they are not the sole determinants.

Question 3

Homologous chromosomes:

Accepted Answer

Homologous chromosomes are pairs of chromosomes that carry genes for the same traits, but may have different versions of those genes (alleles). They are not genetically identical, but they are similar in structure and function. They are inherited from both parents – one homologous chromosome comes from the mother and the other from the father.

Question 4

Human ABO blood types are determined by:

Accepted Answer

ABO blood types are determined by multiple alleles of a single gene, specifically the ABO gene. This gene has at least three alleles: A, B, and O, which produce different glycoproteins on the surface of blood cells.

Question 5

If two alleles influencing the expressed phenotype for a trait are equally expressed, this is an example of:

Accepted Answer

When two alleles influencing the expressed phenotype for a trait are equally expressed, this is an example of codominance. This means that both alleles are expressed equally in the phenotype, resulting in a blended or mixed phenotype. Polymorphism refers to the existence of multiple forms of a gene in a population, pleiotropy refers to one gene affecting multiple traits, and Mendelian inheritance refers to the predictable inheritance patterns of traits based on dominant and recessive alleles.

Question 6

In his experiments with garden peas, Mendel found that one physical unit is inherited from the father and one from the mother.This provided evidence for:

Accepted Answer

Mendel's observations on garden peas showed that one physical unit (allele) is inherited from the father and one from the mother. This supported his law of segregation, which states that pairs of alleles separate during gamete formation, and each gamete receives only one allele from each parent.

Question 7

Use what you know about meiosis to explain Mendel's law of segregation and law of independent assortment.

Accepted Answer

The answer of Use what you know about meiosis to...

Question 8

A trait's heritability is the proportion of its variation that:

Accepted Answer

Heritability is a measure of the proportion of variation in a trait that is due to genetic factors, so the best choice is A. The other options (B, C, and D) are not accurate explanations of heritability.

Question 9

Deoxyribonucleic acid (DNA) differs from ribonucleic acid (RNA) in that it:

Accepted Answer

DNA is indeed the molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses, distinguishing it from RNA, which plays a crucial role in various biological roles in coding, decoding, regulation, and expression of genes.

Question 10

Genetic analysis of haplotypes and variants among living and precontact Native Americans indicates that Native Americans:

Accepted Answer

Studies have shown that the genetic diversity among modern-day Native Americans is similar to that of their ancient ancestors, indicating that there was not a significant decline in genetic diversity after Columbus's arrival. This suggests that Native Americans were able to maintain and preserve their genetic diversity despite the many challenges they faced throughout history. The genetic structure and haplogroups found among Native Americans today are also not recent, but have been present for thousands of years.

Question 11

Chromosome number is reduced during:

Accepted Answer

Meiosis is the process of cell division that reduces the chromosome number by half, going from diploid (2n) to haploid (n) cells. Mitosis, recombination, and translation do not involve a reduction in chromosome number.

Question 12

DNA:

Accepted Answer

DNA is a double-stranded molecule that contains four different nucleotide bases (adenine, thymine, guanine, and cytosine) and serves as a blueprint for cellular function. It does not contain the base uracil, which is found in RNA.

Question 13

Microsatellites are:

Accepted Answer

Microsatellites are highly individualized repetitive stretches of nuclear DNA that are used in genetic research for individual identification and population studies. They are also known as short tandem repeats (STRs) or simple sequence repeats (SSRs). They were discovered in the 1980s and 1990s, well after Watson and Crick's research on DNA structure.

Question 14

Individuals whose blood type is A and who carry both dominant and recessive genes at this locus have a genotype of:

Accepted Answer

Individuals with blood type A can have a genotype of either AA or AO. The AA genotype means they have two dominant A alleles while the AO genotype means they have one dominant A allele and one recessive O allele. Therefore, individuals whose blood type is A and who carry both dominant and recessive genes at this locus have a genotype of AO.

Question 15

Somatic cells are characterized by all of the following EXCEPT:

Accepted Answer

Somatic cells are diploid and contain a complete copy of an organism's DNA, meaning they have two copies of each chromosome. They are used in multiple tissues throughout the body, contain a nucleus at some stage of their development, but they do not contain half a copy of an organism's DNA. Gametes (sperm and egg cells) contain half a copy of an organism's DNA because they are haploid, meaning they only have one copy of each chromosome.

Question 16

The presence of a recessive allele:

Accepted Answer

A recessive allele can be masked by a dominant allele in the phenotype, meaning that it is not expressed or visible. This is because the dominant allele overrides the expression of the recessive allele. Therefore, the presence of a recessive allele cannot always be determined from the phenotype.

Question 17

A doctor finds that the mammary glands of a woman are not functioning due to a genetic abnormality that influences the structural design of the thoracic cavity.This is likely the result of a mutation:

Accepted Answer

Hox genes play a crucial role in the development and patterning of the body plan, including the formation of mammary glands. Mutations in these genes can result in structural abnormalities in the thoracic cavity, which may impact the function of the mammary glands. Mutations on the sex chromosomes or HSV-1 are unlikely to directly impact the structures associated with mammary gland function. Therefore, the best answer is B).

Question 18

In 2004, the Human Genome Project published a human genome map indicating that _______ genes are responsible for the human body's proteins.

Accepted Answer

The Human Genome Project published in 2004 concluded that there are 20,000-25,000 genes responsible for the proteins in the human body. This was a significant finding in genetics and has helped advance research in various fields such as personalized medicine and genetic disorders. Options A, B, and D are outside of the range of genes identified in the project.

Question 19

Describe the steps involved in protein synthesis.

Accepted Answer

The answer of Describe the steps involved in protein synthesis....

Question 20

Polymerase chain reaction (PCR):

Accepted Answer

PCR is a powerful tool for genetic analysis that allows us to amplify small sequences of DNA for study, even if the sample size is very small, such as DNA obtained from ancient skeletons. This allows us to explore the origins and movements of populations using genetic methods. Therefore, all of the options A, B, and C are correct.

Quiz 3: Genetics: Reproducing Life and Producing Variation