Deck 7: Are You Only as Smart as Your Genes? Mendelian and Quantitative Genetics

Question 1

Which of the following is a true statement about chromosomes?

A) Only eukaryotic cells contain chromosomes.
B) Chromosomes are made of carbohydrates.
C) Genes are found on chromosomes.
D) The most complex organisms have the largest number of chromosomes.

Answer 1

C

Question 2

Assuming that the genes are on separate chromosomes, an organism with the genotype AaBb will make gametes in the following proportions: 1/4 AB, 1/4 Ab, 1/4 aB, and 1/4 ab. This is an example of

A) independent assortment.
B) mutation.
C) random fertilization.
D) segregation.

Answer 2

A

Question 3

Half of the gametes produced by an organism with the genotype Aa will receive the A allele, while half will receive the a allele. This is a demonstration of

A) independent assortment.
B) mutation.
C) random fertilization.
D) segregation.

Answer 3

D

Question 4

Specialized cells used for sexual reproduction (for example, sperm cells)are called ________.

Question 5

The members of a pair of chromosomes (for example, the two copies of chromosome 1)are called

A) alleles.
B) gametes.
C) homologous chromosomes.
D) sister chromatids.

Question 6

Gametes fuse together during

A) embryonic development.
B) fertilization.
C) meiosis.
D) mitosis.

Question 7

The growth and reproduction of an individual is called its

A) life cycle.
B) genotype.
C) phenotype.
D) normal distribution.

Question 8

Segments of DNA that generally code for proteins are called ________.

Question 9

Which of the following is true about genes that are located on different chromosomes?

A) These genes are inherited independently of each other.
B) Only the dominant alleles of these genes tend to be inherited together.
C) These genes are always inherited together.
D) These genes are more likely to undergo mutation.

Question 10

Segregation of alleles occurs when

A) homologous chromosomes separate during meiosis.
B) homologous chromosomes separate during mitosis.
C) sister chromatids separate during meiosis.
D) sister chromatids separate during mitosis.

Question 11

Which if the following is the correct sequence of how an animal is "built"?

A) fertilization ? meiosis ? zygote ? embryo
B) meiosis ? fertilization ? zygote ? embryo
C) fertilization ? zygote ? meiosis ? embryo
D) meiosis ? fertilization ? embryo ? zygote

Question 12

A mistake made during copying of genetic information is called a

A) genotype.
B) mutation.
C) variance.
D) zygote.

Question 13

Prokaryotes, like bacteria, contain a single ________ that is circular.

Question 14

Alternate forms of a gene are called

A) alleles.
B) chromosomes.
C) gametes.
D) homologues.

Question 15

Which of the following is a true statement about chromosome number?

A) Among all known living creatures, humans have the most chromosomes.
B) Animals have more chromosomes than plants.
C) Eukaryotes have more chromosomes than prokaryotes.
D) All organisms have pairs of chromosomes.

Question 16

A typical gene contains the instructions for making a

A) chromosome.
B) lipid.
C) polysaccharide.
D) protein.

Question 17

What causes the differences between two human cell types (for example, a skin cell and a brain cell)?

A) Different cell types begin with the same genes but eliminate certain genes as they develop.
B) Different cell types contain different genes.
C) Different cell types contain different proteins that give each cell a different function.
D) Different cell types contain the same genes but use different combinations of them.

Question 18

If the DNA contained in the chromosomes of an organism is similar to an instruction manual, then what are the genes "instructing" the cell to do?

A) grow in size until a certain point is reached, then reproduce itself
B) convert carbohydrates into enzymes
C) change shape and structure to meet the demands of the local environment
D) synthesize specific proteins from amino acids

Question 19

Monozygotic (identical)twins are the result of

A) one sperm fertilizing two different eggs.
B) one egg being fertilized by two different sperm.
C) one embryo splitting to become two embryos.
D) two different sperm fertilizing two different eggs.

Question 20

Which of these produces genetic diversity in a population?

A) independent assortment
B) random fertilization
C) segregation
D) mutation

Question 21

Cystic fibrosis is caused by the allele f, which is completely recessive to the normal dominant allele F. Consider a couple with the genotype Ff. What is the chance that their first child will develop cystic fibrosis?

A) 0%
B) 25%
C) 50%
D) 75%

Question 22

Gregor Mendel's genetic research

A) was not appreciated by the scientific community until after he died.
B) focused on pea plants because they have fewer than four different heritable traits.
C) produced results that can be used to predict heritability in plants but not animals.
D) included detailed studies on the phenomena of codominance and incomplete dominance.

Question 23

In humans, heterozygotes are referred to as ________, particularly when the recessive allele is associated with a genetic disease.

A) vectors
B) dizygotic
C) carriers
D) qualitative

Question 24

In a certain plant species, thick-shelled seeds are caused by the dominant allele T, while thin-shelled seeds are caused by the recessive allele t. Consider an individual plant that has thin-shelled seeds. What is the genotype of this individual?

A) TT
B) tt
C) Tt
D) tt or Tt

Question 25

If you're interested in studying one gene within a human, and each gene has two alleles, then the Punnett square that you would use to predict the inheritance of the alleles would contain how many total boxes?

A) 2
B) 4
C) 8
D) 16

Question 26

A mutation in a gene

A) might have no effect on the protein encoded by the gene.
B) must result in the creation of a nonfunctional protein.
C) cannot result in a protein with a new function.
D) invariably results in a change in the phenotype of an organism.

Question 27

If a certain recessive allele can cause a change in cellular proteins that ultimately leads to circulatory problems and premature death, then

A) any homozygous individual will always have an advantage over any heterozygous individual.
B) any heterozygous individual will always have an advantage over any homozygous individual.
C) any homozygous individual will always have a disadvantage compared to any heterozygous individual.
D) any heterozygous individual will have an advantage over any homozygous recessive individual.

Question 28

CFTR/CFTR-?F508 refers to the

A) dominant allele that causes cystic fibrosis.
B) recessive allele that causes cystic fibrosis.
C) homozygous genotype of a cystic fibrosis victim.
D) heterozygous genotype of a carrier of cystic fibrosis.

Question 29

Combined, your parents could have produced as many as ________ different types of children, genetically speaking.

A) 46
B) 285
C) 8 million
D) 64 trillion

Question 30

Homologous chromosomes

A) almost always contain identical alleles.
B) generally contain the same genes.
C) are inherited together because they don't separate during meiosis.
D) are fewer in body cells than in gametes.

Question 31

Which of the following situations most likely describes a recessive genetic disorder?

A) The mutant allele of the gene encodes a completely nonfunctional protein.
B) The mutant allele of the gene encodes a protein that has both the normal function and a new, harmful function.
C) The mutant allele of the gene encodes a protein that has a new, harmful function.
D) The mutant allele of the gene encodes a protein with the normal function but twice the normal activity.

Question 32

Which of the following would be expected in normal eye cells but not in normal heart cells?

A) the protein rhodopsin
B) light-detecting mitochondria
C) DNA that codes for the conversion of mitochondria into rhodopsin
D) genes for the production of rhodopsin

Question 33

DNA is often likened to an instruction manual. According to this analogy, the typographical errors that would inevitably result when the DNA "manual" is transcribed would be similar to

A) dominant alleles.
B) recessive alleles.
C) mutations.
D) homologous chromosomes.

Question 34

A typical recessive allele codes for a

A) lethal protein.
B) nonfunctional protein.
C) functional protein.
D) mutant protein.

Question 35

A heterozygous organism

A) always shows a recessive trait.
B) can't produce gametes.
C) has two identical alleles of a gene.
D) has two different alleles of a gene.

Question 36

Cystic fibrosis is caused by the allele f, which is completely recessive to the normal dominant allele F. Consider a couple with the genotype Ff. What is the chance that their second child will develop cystic fibrosis?

A) 25%
B) 50%
C) 75%
D) 100%
E) It depends on which alleles were inherited by their first child.

Question 37

A dominant genetic disorder occurs when

A) only one allele of the gene is the mutant allele.
B) both alleles of the gene are the mutant allele.
C) neither allele of the gene is the mutant allele.
D) either one or both alleles of the gene are mutant.

Question 38

How many different types of offspring (genotypes)are possible as a result of this cross, according to the Punnett square?

A) 1
B) 2
C) 3
D) 4

Question 39

Because of the law of independent assortment,

A) an individual will get most of their alleles from one parent.
B) monozygotic twins will have about 50% of their alleles in common.
C) two typical siblings will have about 50% of their alleles in common.
D) dizygotic twins will have 100% of their alleles in common.

Question 40

Fraternal twins are also referred to as

A) dizygotic.
B) identical.
C) monozygotic.
D) heterozygous.

Question 41

Which of these describes influence on a trait that is due to genes and not environment?

A) Hair dye turns Angela's brown hair to red.
B) Sandy's hair becomes blonder when she spends time out in the sun.
C) Jen has brown hair, just like her mother and father.
D) Identical twins Kiera and Tanya have different colored hair.

Question 42

How many different kinds of gametes can be made by an individual with the genotype AaBb?

A) 2
B) 4
C) 8
D) 16

Question 43

Consider a trait that shows continuous variation. If the variance is low, then

A) the majority of individuals will be far above the mean.
B) the majority of individuals will be very close to the mean.
C) the majority of individuals will be far below the mean.
D) relatively few individuals will be very close to the mean.

Question 44

Which of the following is a cross between parents who each have two different alleles for each of two different genes?

A) AAbb x aaBB
B) aabb x AABB
C) AaBb x AaBb
D) AaBB x AABb

Question 45

Huntington's disease is caused by the allele H, which is completely dominant to the normal recessive allele h. Consider a couple where the man has the genotype Hh, and the woman has the genotype hh. What is the chance that their first child will develop Huntington's disease?

A) 0%
B) 25%
C) 50%
D) 75%

Question 46

A scientist studying the heritability of IQ would expect to find the highest correlation between the IQ scores of

A) two unrelated children.
B) a child and his mother.
C) monozygotic twins.
D) dizygotic twins.

Question 47

The ________ of an organism is the genetic makeup of that organism.

Question 48

A ________ cross is a genetic cross involving two traits.

Question 49

In pea plants, the allele for purple flowers (P)is dominant to the allele for white flowers (p). In a cross between a purple-flowered plant and a white-flowered plant, all 73 of the offspring plants had purple flowers. Which of the following most likely describes the cross above?

A) pp x pp
B) Pp x Pp
C) PP x PP
D) PP x pp

Question 50

In humans, straight thumbs are caused by the dominant allele T, while individuals who are tt have thumbs that curve backward ("hitchhiker's thumb"). Consider a family in which the father has straight thumbs, and both the mother and their only child have curved thumbs. What is the chance that their next child will have curved thumbs?

A) 25%
B) 50%
C) 75%
D) 100%

Question 51

What is the term used to describe a trait that is controlled by many genes?

A) dihybrid
B) dominant
C) heritable
D) polygenic

Question 52

An individual who is a carrier for a recessive genetic disorder but does not have symptoms of the disorder is

A) heterozygous.
B) homozygous for the recessive allele.
C) homozygous for the dominant allele.
D) either homozygous for the recessive allele or heterozygous.

Question 53

The ________ of an organism refers to its physical traits.

Question 54

Typical quantitative traits

A) are easy to follow using Punnett squares.
B) are not affected by the environment.
C) are usually influenced by only one gene.
D) show continuous variation.

Question 55

The IQ test developed by Alfred Binet was designed to

A) measure intelligence based on the most accepted theory of the time.
B) compare the intelligence of different cultural subpopulations in the general population.
C) determine the relative effects of genes and environment on intelligence.
D) identify school children in need of remedial help.

Question 56

A trait that shows continuous variation is typically influenced by

A) genes only.
B) environmental factors only.
C) both genes and environmental factors.
D) neither genes nor environmental factors.

Question 57

An individual who has two copies of the same allele is ________ for that allele.

Question 58

Which of the following is an example of a quantitative trait in humans?

A) cheek dimples
B) number of toes
C) musical ability
D) cystic fibrosis

Question 59

Which of the following is an example of a qualitative trait in humans?

A) height
B) skin color
C) Huntington's disease
D) intelligence

Question 60

A ________ trait has an "off-or-on" character, where individuals have either one phenotype or another (for example, purple vs. white flowers).

Question 61

Which of the following pairs of people would provide the most useful information to geneticists, regarding the heritability of a certain trait?

A) non-twin siblings separated into different households soon after birth
B) monozygotic twins separated into different households soon after birth
C) non-twin siblings raised in the same household since birth
D) monozygotic twins raised in the same household since birth

Question 62

The highest point on a bell-shaped curve represents the

A) maximum amount of variation in a trait.
B) heritability value of a trait.
C) number of people in the population who are heterozygous.
D) mean of the population.

Question 63

What can be concluded about the ability of doctorate-category sperm to help produce children that are smarter than average?

A) Because intelligence has no genetic basis, there's no real reason to expect children produced by this type of sperm to be smarter than average.
B) Children produced by this type of sperm have an approximately 72% chance of being more intelligent than average.
C) Children produced by this type of sperm will be smarter than average only if the mother has a high IQ.
D) There is currently no way to predict whether children produced by this type of sperm will be smarter than average.

Question 64

If the estimated heritability of a trait is approximately 0.50, then

A) the environment must have little to no influence over the expression of the trait.
B) genes exclusively control the expression of the trait in at least 50% of the population.
C) at least 50% of the variation in the trait in the population is due to genetic differences.
D) the environment completely controls the variation in the trait in the population.

Question 65

The large variation in shoe size among humans is due to a trait that is

A) dizygotic.
B) qualitative.
C) quantitative.
D) polygenic.

Question 66

The difference between the lowest and highest values on the x-axis of a normal distribution curve represents the ________ for the population that is being studied.

A) bell-shaped curve
B) mean value
C) variance
D) frequency distribution

Question 67

According to this graph, what can be concluded about immunity in these birds?

A) The heritability value is approximately 0.50.
B) Genes explain all the variation in immunity among birds in this population.
C) Environment still plays a role in these birds' immunity, even though heritability is high.
D) The heritability of immunity follows a bell-shaped curve, indicating a normal distribution.

Question 68

The estimated influence of genes (as opposed to environment)on a trait is called ________.

Question 69

According to one study, the heritability of IQ score in humans has a value of 0.52. What does this tell us about the role of "nature" vs. "nurture" in determining intelligence in humans?

A) Intelligence is a qualitative trait, affected by both genetics and the environment, and it can't be predicted by heritability scores.
B) Children of highly intelligent parents will likely be very intelligent, regardless of the environment in which they're raised.
C) There is an approximately equal chance that children of intelligent parents will be as intelligent as their parents, depending on the environment in which they're raised.
D) High heritability values don't mean that the intelligence of children can be accurately predicted because the environment plays a strong role.

Question 70

Which of the following was a conclusion based on experiments with "maze-bright" and "maze-dull" rats?

A) An enriched environment increases maze-running ability only in dull rats.
B) A poor environment adversely affects maze-running ability in both bright and dull rats.
C) Maze-running ability is highly heritable and unaffected by environment.
D) Maze-running ability is based entirely on environment and unaffected by genes.

Question 71

A ________ trait shows continuous variation, where there is a large range of phenotypes in a population (for example, height or skin color).