bio 100 exam 3 (class 13-19 assignments)

Assume a phenotype is determined by one gene with a dominant allele and a recessive allele. If one parent is heterozygous and the other parent is homozygous dominant, what is the probability of producing a homozygous recessive offspring? 0% 75% 50% 100% 25%

0%

Humans have how many autosomes? 46 pairs 22 pairs 44 pairs 23 pairs 26 pairs

22 pairs

A human female has _____ chromosomes in each skin cell and _____ chromosomes in each egg. 23; 23 46; 46 46; 23 23; 46 92; 46

46; 23

Assume a phenotype is determined by one gene with a dominant allele and a recessive allele. If both parents are heterozygous, what is the probability of an offspring being a carrier of the recessive allele? 75% 50% 0% 25% 100%

50%

Assume a phenotype is determined by one gene with a dominant allele and a recessive allele. If one parent is homozygous recessive and the other is heterozygous, what is the probability that an offspring will have the recessive phenotype? 50% 100% 25% 0% 75%

50%

A woman is heterozygous for the CF-associated gene (the alleles are represented here by the letters A and a. Assuming that meiosis occurs normally, which answer choice represents eggs that she can produce? A Aa A or a a AA

A or a

Which statement is NOT a correct description of the relationship between UV light in the environment and how it affects humans? A. In a high-UV-light environment, skin color is more likely to be lighter. B. In a low-UV-light environment, less melanin is likely to be produced. C. In a low-UV-light environment, folate is not destroyed. D. In a high-UV-light environment, more melanin is likely to be produced. E. In a high-UV-light environment, plentiful vitamin D can be synthesized.

A. In a high-UV-light environment, skin color is more likely to be lighter.

Which statement about evolution by natural selection is false? A. Natural selection is a random change in allele frequencies over generations. B. Evolution by natural selection affects populations of organisms, not individual organisms. C. Natural selection favors those traits that confer higher fitness in the environment. D. Natural selection allows organisms with higher fitness to reproduce more successfully. E. Evolution by natural selection occurs more rapidly in organisms with high reproductive rates.

A. Natural selection is a random change in allele frequencies over generations.

Which is a primary difference between all prokaryotes and eukaryotic cells? A. Prokaryotes have DNA that floats freely in the cytoplasm. B. Prokaryotes are similar in size to eukaryotic cells. C. Prokaryotes have ribosomes, just like eukaryotic cells. D. Some prokaryotes contain mitochondria. E. none of these

A. Prokaryotes have DNA that floats freely in the cytoplasm.

Which statement is true about all animals? A. They are all multicellular eukaryotic heterotrophs. B. They all have an endoskeleton and bilateral symmetry. C. They are all single-celled species that can make their own food. D. They all have segmented body parts. E. none of these

A. They are all multicellular eukaryotic heterotrophs.

An organism's fitness depends on its _____. A. ability to survive and reproduce B. population C. ability to mutate D. physical size E. ability to swap genetic material with other organisms

A. ability to survive and reproduce

Ultraviolet light destroys which vitamin essential for cell division? A. folate B. D C. B12 D. B6 E. B2

A. folate

Which description is a eukaryote group that evolved earlier than the others? A. nonvascular, nonflowering plants B. bilaterally symmetric vertebrates C. arthropods with exoskeletons D. angiosperm plants E. vertebrates with endoskeletons

A. nonvascular, nonflowering plants

Assume a phenotype is determined by one gene with a dominant allele and a recessive allele. If one parent is homozygous dominant (AA) and the other parent is homozygous recessive (aa), what genotype(s) might their offspring have? AA, Aa, aa Aa AA, Aa AA, aa Aa, aa

Aa

Which of the following statements about the three domains of life is TRUE? A. Archaea is most closely related to Bacteria. B. Archaea is most closely related to Eukarya. C. Bacteria is most closely related to Eukarya. D. Bacteria and Archaea are equally related to the Eukarya. E. Bacteria and Archaea have no evolutionary relationship to Eukarya.

B. Archaea is most closely related to Eukarya.

The tree of life has been rearranged into three domains based on what evidence? A. comparative anatomy B. DNA similarities C. homologous structures D. anatomical evidence E. fossil evidence

B. DNA similarities

Which statement is false? A. All organisms belong to one of three domains: Bacteria, Archaea, and Eukarya. B. Once an organism is classified, the classification cannot change. C. DNA evidence can be used to classify organisms. D. Humans belong to the domain Eukarya. E. Prokaryotes can be found in both the Archaea and Bacteria domains.

B. Once an organism is classified, the classification cannot change.

What do all members of the informal group known as protists have in common? A. They have nothing in common. B. They are all eukaryotic. C. They all carry out photosynthesis. D. They are all human parasites. E. They are all decomposers.

B. They are all eukaryotic.

Which of the following is/are used to examine inheritance over generations? A. genotypes B. a pedigree chart C. phenotypes D. karyotypes

B. a pedigree chart

Evolution may best be explained as a: A. change in the frequency of proteins in a population over time. B. change in the frequency of alleles in a population over time. C. change in the number of individuals in a population over time. D. change in the proportion of males to females in a population over time. E. change in the birth rate in a population over time.

B. change in the frequency of alleles in a population over time.

Natural selection causes: A. changes in an individual's genes. B. changes in allele frequencies within a population. C. a decrease in reproductive fitness in a population. D. the inheritance of acquired characteristics. E. changes in the mechanism of inheritance.

B. changes in allele frequencies within a population.

Of the taxonomic categories below, which has the greatest number of organisms or most inclusive category? A. kingdom B. domain C. phylum D. class E. order

B. domain

Skin color is determined by the amount of _______ a person has in their skin. A. vitamin D B. melanin C. fat D. lignin E. folate

B. melanin

Founder effect describes a: A. new population arising from a migration of a population. B. new population arising from a few individuals. C. population that has undergone mutation. D. population that is largely interbreeding. E. population that results from one species crossing with another.

B. new population arising from a few individuals.

Of the taxonomic categories below, which has the least number of organisms or least inclusive category? A. kingdom B. order C. domain D. phylum E. class

B. order

This gas began to accumulate between 3 and 2.5 billion years ago. A. hydrogen B. oxygen C. methane D. ammonia E. carbon dioxide

B. oxygen

Which two domains contain prokaryotic organisms? A. Archaea and Eukarya B. Monera and Eukarya C. Bacteria and Archaea D. Archaea and Monera. E. Bacteria and Monera

C. Bacteria and Archaea

Ultraviolet light is essential for the formation of this vitamin. A. A B. B6 C. D D. K E. B9

C. D

What is the evolutionary process called that causes antibiotic-resistant bacteria to increase and antibiotic-sensitive bacteria to decrease in an environment where antibiotics are present? A. bacterial selection B. antibiotic selection C. natural selection D. environmental selection E. evolutionary selection

C. natural selection

Margulis' theory of the origin of mitochondria proposes that mitochondria _____. A. is the ancestor of all eukaryotic cells B. was the first life form on Earth C. originated when a larger anaerobic cell engulfed a smaller aerobic cell D. originated when a larger cell engulfed a smaller photosynthetic cell E. originated long before the earth's atmosphere filled with oxygen

C. originated when a larger anaerobic cell engulfed a smaller aerobic cell

The Miller-Urey experiment was important because it showed _____. A. exactly how life began on Earth B. when life first began on Earth C. that is was possible to form organic molecules from inorganic molecules D. the kinds of rocks that would contain fossils E. all of these

C. that is was possible to form organic molecules from inorganic molecules

When life first began, A. the planet had a lot of oxygen in the atmosphere and was much warmer. B. the planet had a lot of oxygen in the atmosphere and was much cooler. C. the planet had a lot of methane in the atmosphere and was much warmer. D. the planet had a lot of methane in the atmosphere and was much cooler. E. the planet had very little oxygen in the atmosphere and was much cooler.

C. the planet had a lot of methane in the atmosphere and was much warmer.

Which of these would be used to develop a phylogenetic tree? A. fossil records B. physical traits C. shared DNA sequences D. All of these are used to develop a phylogenetic tree. E. None of these are used to develop a phylogenetic tree.

D. All of these are used to develop a phylogenetic tree.

A phylogenetic tree represents: A. a grouping of organisms on the basis of shared structural features. B. a grouping of organisms on the basis of cell type. C. a grouping of organisms on the basis of complexity. D. a grouping of organisms on the basis of evolutionary history. E. a grouping of organisms on the basis of where they are found.

D. a grouping of organisms on the basis of evolutionary history.

A population is described as: A. all the members of the same species located on a continent. B. the species that live in a geographic area. C. all the species occupying a specific locale. D. all the members of the same species living in the same area. E. the species richness.

D. all the members of the same species living in the same area.

The collection of _____ in a population constitutes that population's gene pool. A. genes B. genotypes C. phenotypes D. alleles D. chromosome

D. alleles

All of the following are true of genetic drift, EXCEPT: A. changes in allelic frequencies are always random. B. changes in allelic frequencies may benefit the population. C. changes in allelic frequencies may harm the population. D. genetic drift has the greatest influence on large populations. E. over time, genetic drift decreases the genetic diversity of a population.

D. genetic drift has the greatest influence on large populations.

Jablonski and Chaplin hypothesized that darker skin is advantageous in __________ UV environments because darker skin ___________. A. high-; increases the rate of folate synthesis B. low-; allows more vitamin D to be produced C. low-; allows more folate to be produced D. high-; protects folate from degradation E. high-; reduces vitamin D production

D. high-; protects folate from degradation

All of the following are TRUE of folate, EXCEPT: A. decreased folate levels in the mother are linked to spina bifida in the baby. B. it can be found in beans, citrus fruit, and dark green, leafy vegetables. C. it is needed for DNA replication and cell division. D. it increases with increased exposure to the sun. E. it helps sperm develop normally.

D. it increases with increased exposure to the sun.

This molecule protects folate from destruction by damaging ultraviolet light. A. chlorophyll B. bilirubin C. calcium D. melanin E. retinol

D. melanin

The biological species concept defines a species: A. on the basis of similar physical appearance. B. on the basis of close genetic relationships. C. on the basis of similar levels of genetic diversity. D. on the basis of the ability to mate and produce fertile offspring. E. on the basis of recognizing one another's mating behaviors.

D. on the basis of the ability to mate and produce fertile offspring.

Which are all members of the domain Eukarya? A. animals, plants, protists, and prokaryotes B. protists, animals, and prokaryotes C. eukaryotes and prokaryotes D. plants, animals, fungi, and protists E. plants, animals, fungi, and bacteria

D. plants, animals, fungi, and protists

Which is necessary for natural selection to proceed? A. variation within a population B. a mechanism of inheritance C. acquisition of adaptations D. generations reproducing over time E. All of the above.

E. All of the above.

Which statement is false about fungi? A. Many fungi form mycelia of hyphae. B. Some fungi live on trees. C. Some fungi can live symbiotically with other organisms. D. Most fungi are multicellular, although some are unicellular. E. Most fungi get their nutrients by ingesting small pieces of other living organisms.

E. Most fungi get their nutrients by ingesting small pieces of other living organisms.

Which of the following is more fit? A. a 5000-year-old bristlecone pine tree that produced 1 offspring every 100 years B. a 5000-year-old bristlecone pine tree that produced 3 offspring every 100 years C. a 3000-year-old bristlecone pine tree that produced 100 offspring every 100 years D. a 2000-year-old bristlecone pine tree that produced 100 offspring every 10 years E. a 500-year-old bristlecone pine tree that produced 100 offspring every year

E. a 500-year-old bristlecone pine tree that produced 100 offspring every year

The evidence that scientists currently have suggests that life on Earth _____. A. began in the water B. first evolved around 3,500 million years ago C. began as single-celled organisms D. first evolved in the water around 3,500 million years ago E. all of these

E. all of these

Which of these is NOT an example of adaptive evolution? A. founder effect B. mutation C. gene flow D. bottleneck E. all of these

E. all of these

All of the following are true of phylogenetic trees, EXCEPT: A. more primitive species are near the bottom, whereas more modern species are at the tips. B. a node represents the last common ancestor of the species above that point in the tree. C. phylogenetic trees show the evolutionary relationships among species. D. DNA evidence has been very useful in determining relationships among species. E. extinct species are never included in phylogenetic trees.

E. extinct species are never included in phylogenetic trees.

All of the following are TRUE of vitamin D, EXCEPT: A. vitamin D helps the body absorb calcium. B. sunlight is important for vitamin D production. C. vitamin D is important for healthy bone growth. D. the need of the body for vitamin D is one factor in the evolution of skin color. E. pregnant women should reduce vitamin D in their diet to avoid birth defects.

E. pregnant women should reduce vitamin D in their diet to avoid birth defects.

What does it mean to say that a person has a heterozygous genotype for a disease and no disease phenotype? It means that the person has two copies of the normal allele.It means that the person has two copies of the disease allele. It means that the person is a carrier who has already sired children who show symptoms of the disease. It means that the person does not show symptoms of the disease if the disease allele is recessive. It means that the person exhibits the symptoms of the disease if the disease allele is recessive.

It means that the person does not show symptoms of the disease if the disease allele is recessive.

A karyotype is: a. a diagram of all chromosomes in a cell. b. your blood group. c. DNA stripped of all its proteins. d. a chart showing your detailed genetic makeup. e. a diagram depicting the inheritance pattern of a disease allele within a family

a. a diagram of all chromosomes in a cell.

The term autosome refers to: a. all chromosomes, except the X and Y. b. all chromosomes, including the X but not the Y. c. all chromosomes, including the Y but not the X. d. all chromosomes, including the X and Y. e. only the X and Y chromosomes.

a. all chromosomes, except the X and Y.

One of the purposes of meiosis is to _____. a. reduce the chromosome number in each resulting cell by half b. increase genetic diversity in the diploid-starting cells c. double the number of chromosomes per gamete d. produce four zygotes instead of only two (as produced in mitosis) e. increase the number of embryos per fertilization

a. reduce the chromosome number in each resulting cell by half

Women can inherit alleles of a gene called BRCA1 that puts them at higher risk for breast cancer. The alleles associated with elevated cancer risk are dominant. Of the genotypes listed below, which carries the lowest genetic risk of developing breast cancer? BB bb Bb Bb and bb All of these genotypes carry equal risk.

bb

How do haploid gametes result in diploid offspring? a. A haploid egg and a haploid sperm fuse to form a diploid zygote that grows by meiosis after fertilization. b. A diploid sperm fertilizes a diploid egg, and the resulting diploid zygote then grows by mitosis to form an embryo. c. A haploid egg and a haploid sperm fuse to form a diploid zygote that grows by mitosis after fertilization. d. A diploid egg and a diploid sperm undergo fertilization to form a diploid zygote that grows through meiosis. e. A diploid egg and a diploid sperm fuse, undergo meiosis once to form a diploid zygote, which grows by mitosis.

c. A haploid egg and a haploid sperm fuse to form a diploid zygote that grows by mitosis after fertilization.

What are X-linked traits? a. Traits that only affect females because females have two X chromosomes. b. Dominant traits located on X chromosomes. c. Diseases or phenotypes that are determined by genes on an X chromosome

c. Diseases or phenotypes that are determined by genes on an X chromosome

A bottleneck is best described as: a. an expansion of a population from a small group of founders. b. a small number of individuals leaving a population. c. a reduction in the size of an original population followed by an expansion in size as the surviving members reproduce. d. the mixing and mingling of alleles by mating between members of different populations. e. an example of natural selection.

c. a reduction in the size of an original population followed by an expansion in size as the surviving members reproduce.

Why are more males than females affected by X-linked recessive genetic diseases? a. Males and females are affected equally by X-linked recessive genetic conditions. b. Females have no Y chromosome to mask the X-linked recessive allele. c. Females have two Y chromosomes and cannot be affected by X-linked traits. d. Males have a Y chromosome that cannot mask the X-linked recessive allele. e. Females have an additional Y chromosome to mask the X-linked recessive allele.

d. Males have a Y chromosome that cannot mask the X-linked recessive allele.

Meiosis differs from mitosis in the _____. a. number of sister chromatids in the starting cells b. number of cells produced immediately after the starting cells divide c. number of chromosomes in the starting cells d. number of chromosomes in each ending cell e. way in which sister chromatids separate

d. number of chromosomes in each ending cell

Allele frequencies of a population can change by: a. natural selection. b. genetic drift. c. mutations in the gene pool. d. founder effect. e. All of the above.

e. All of the above

If a man has an X-linked recessive disease, can his sons inherit that disease from him? a. No, all his sons have one X chromosome. b. Yes, all his sons inherit their X chromosomes maternally. c. Yes, all his sons inherit their Y chromosomes maternally. d. Yes, all his sons have one X chromosome. e. No, all his sons inherit their X chromosomes maternally.

e. No, all his sons inherit their X chromosomes maternally.

A phenotype is: a. a genetic trait b. an allele descriptor c. a karyotype d. an inherited disorder e. a physical trait

e. a physical trait

What is a genotype? A and B the measurable or visual traits of an individual the same as the phenotype the genetic makeup of an individual defined by one's phenotype

the genetic makeup of an individual