Question 1

Genes affect disorders such as alcohol use disorder and nearsightedness, but research indicates that the environment plays a role as well.

Accepted Answer

While genes can predispose individuals towards certain disorders, environmental factors such as stress and exposure to alcohol can also influence the development and severity of conditions such as alcohol use disorder. Similarly, while genetics can contribute to the development of nearsightedness, factors such as prolonged near work and lack of outdoor activity are also known to play a role.

Question 2

Almost every trait is polygenic, which means that it is affected by many genes.

Accepted Answer

Polygenic traits are affected by multiple genes, often with small effects, and are therefore influenced by genetic variation at many different loci. This is true for most complex traits, including height, intelligence, and susceptibility to certain diseases.

Question 3

Genes and alleles for alcohol use disorder have been found exclusively on the Y chromosome.

Accepted Answer

Genes and alleles for alcohol use disorder have not been found exclusively on the Y chromosome. They are located on various chromosomes, including 1, 2, 3, 5, 7, 8, 10, 11, 12, 15, and X.

Question 4

Genes, culture, and age all affect vision.

Accepted Answer

Genes can determine the shape of the eye and susceptibility to certain eye conditions. Culture can affect visual perception and interpretation. As people age, changes in the eye, such as a reduction in pupil size and a decrease in the ability to focus on near objects, can affect vision.

Question 5

The full set of genes for a living organism is called a _____.
A) genome
B) cell
C) DNA
D) zygote

Accepted Answer

The full set of genes for a living organism is called a genome. This includes all of the DNA contained within the organism's cells. Option B, cell, refers to the basic unit of life, but does not encompass all of the organism's genetic information. Option C, DNA, refers to the genetic material itself, but not the entire set of genes. Option D, zygote, refers to a fertilized egg, which contains only half of the organism's genetic material.

Question 6

The 23 pairs of chromosomes in a zygote duplicate and form two complete sets of the genome. This process is referred to as duplication.

Accepted Answer

The duplication of the 23 pairs of chromosomes in a zygote results in two complete sets of the genome.

Question 7

When a person inherits a recessive gene that is not expressed in the phenotype, that person is a carrier of the gene.

Accepted Answer

When a person inherits one copy of a recessive gene, it is often not expressed in the phenotype because the dominant allele masks its effects. However, that person is still a carrier of the gene and can potentially pass it on to their offspring.

Question 8

Every ovum that a woman creates contains an X chromosome.

Accepted Answer

Yes, every ovum (egg cell) contains an X chromosome. During the process of meiosis, the ovum receives one of two X chromosomes from the mother's pair of X chromosomes.

Question 9

If the 23rd pair of chromosomes contains one X chromosome and one Y chromosome, then the individual is male.

Accepted Answer

This is because males have one X and one Y chromosome, while females have two X chromosomes (XX).

Question 10

The general term for the techniques designed to help infertile couples conceive and then sustain a pregnancy is in vitro fertilization (IVF).

Accepted Answer

The general term for techniques designed to help infertile couples conceive and then sustain a pregnancy is Assisted Reproductive Technology (ART), of which in vitro fertilization (IVF) is the most common and effective type.

Question 11

The most common extra-chromosome condition is fragile X syndrome.

Accepted Answer

The most common extra-chromosome condition is Down syndrome, not fragile X syndrome.

Question 12

Dizygotic twins originate from the same zygote; therefore, they have the same genotype.

Accepted Answer

Dizygotic twins, also known as fraternal twins, originate from two separate eggs fertilized by two separate sperm cells. As a result, they may have different genotypes just like any other siblings. Only monozygotic twins, also known as identical twins, originate from the same zygote and have the same genotype.

Question 13

The basic unit on a chromosome that is used for the transmission of heredity is called a(n) _____.
A) gene
B) RNA
C) cell
D) protein

Accepted Answer

A gene is the basic unit of heredity that is located on a chromosome, and it carries the instructions for a particular trait. RNA, cells, and proteins are all important components of genetic expression, but they are not the fundamental unit that is transferred from parent to offspring.

Question 14

When the effects of genes add up to make the phenotype, they are called dominant-recessive genes.

Accepted Answer

When effects of genes add up to make the phenotype, they are commonly referred to as additive genes, not dominant-recessive genes. Dominant-recessive genes refer to the expression of a single gene that either masks or is masked by the expression of its alternative allele.

Question 15

Due to biological sex (XX or XY), women become drunk on more alcohol than men.

Accepted Answer

Biological sex does not determine how much alcohol a person can handle. Other factors such as body weight, metabolism, and drinking history are more influential in how alcohol affects an individual.

Question 16

It is the mother's ovum that determines whether the developing baby will become a boy or a girl.

Accepted Answer

It is the sperm from the father that determines the sex of the baby. Sperm can carry either an X or a Y chromosome, while the mother's ovum only carries an X chromosome. An XY combination results in a male, and an XX combination results in a female.

Question 17

Consultation and testing by trained experts that enable individuals to learn about their genetic heritage, including harmful conditions that they might pass along to any children they may conceive, is referred to as couples counseling.

Accepted Answer

The statement is incorrect. The correct term for this type of consultation and testing is genetic counseling, not couples counseling. Couples counseling typically refers to therapy to improve and strengthen relationships between couples.

Question 18

An individual's phenotype is dependent entirely on the individual's genes.

Accepted Answer

An individual's phenotype is influenced by both their genes and the environment. While genes provide the instructions for the traits and characteristics, factors such as diet, exposure to toxins, and stress can affect how those genes are expressed and ultimately impact the phenotype.

Question 19

Heritability indicates how much of the variation of a trait can be traced to genes.

Accepted Answer

Heritability estimates the proportion of variation in a trait that is attributable to genetic factors. Therefore, it indicates how much of the variation of a trait can be traced to genes.

Question 20

The cells that result from the early duplication and division processes are called stem cells, which are able to produce any other specialized cell.

Accepted Answer

Stem cells are undifferentiated cells that have the potential to differentiate into various specialized cell types. They are able to self-renew and differentiate into specific cell types, which makes them an important tool for medical research and regenerative medicine.

Quiz 3: The New Genetics