Part 5 EOC Review

CLASSIFICATION, HEREDITY AND EVOLUTION (25% OF TEST)

SC.912.L.15.1 Evolution

Multiple Choice

The scientific theory of evolution is supported by different types of evidence. The diagrams below show the skeletons of two different animal species. How does comparing the skeletons of these animals provide support for the scientific theory of evolution?

• A. It provides information about the organisms' habitats.

• B. It shows possible common ancestry between organisms

• C. It provides information to determine the organisms' ages

• D. It shows possible chromosomal similarities between organisms.

Explanation

Animals that evolved from a common ancestor will often have similar structures and organs.

Multiple Choice

According to fossil records, the horses that lived 50 million years ago were much smaller, weaker and slower than modern horses. Which process is most likely responsible for the changes that have led to the increased size, strength, and speed in horses?

• A. commensalism

• B. inbreeding

• C. migration

• D. evolution by natural selection

Explanation

Natural selection is the mechanism of evolution, where animals that are more “fit” for a certain environment will naturally be selected to reproduce more often. Over time, new species have evolved from similar ancestral species. 

Multiple Choice

The diagram illustrates an embryonic stage of two organisms.Which of the following can be determined by observing the embryos shown in the diagram?

• A. The organisms share a common ancestry.

• B. The organisms belong to the same genus.

• C. The organisms are native to the same geographic areas

• D. The organisms will grow into anatomically similar adults.

Explanation

During the embryonic stage, before organisms develop many specialized structures, embryos with common ancestry will tend to have many of the same characteristics.

Multiple Choice

Scientists have found evidence that about 2.4 million years ago a gene regulating jaw muscles mutated and may have led to the more graceful human jaw we see today. The diagram below shows the skulls of 3 hominid species. Which statement below most closely explains the link between jaw size and hominid evolution?

• A. The jaws of hominids evolved to be smaller and less protruding over time.

• B. The jaws of hominids evolved to be larger and more protruding over time.

• C. There appears to be no change in the jaws of hominids over time.

• D. The jaws of hominids changed over time due to a change in brain size.

Explanation

Over time, the jaws of hominid species evolved to be smaller, lighter and less protruding. Scientist are now collecting evidence to support the theory that this change in jaw size allowed for larger brains to develop in hominids. 

Multiple Choice

Scientists are studying the evolutionary history of a group of plants in the United States, and they developed an evolutionary tree, as shown below.Which statement can be inferred from the evolutionary tree?

• A. Species 1 is most closely related to Species 8.

• B. Species 2 is most closely related to Species 3.

• C. Species 3 is most closely related to Species 7

• D. Species 5 is most closely related to Species 6.

Explanation

Both species 5 and 6 evolved from the same common ancestor.

Multiple Choice

Scientists are studying the evolutionary history of a group of plants in the United States, and they developed an evolutionary tree, as shown below.What information about the organisms best helps the scientists to determine the evolutionary relationships among them?

• A. DNA sequences

• B. Anatomical features

• C. Habitat types

• D. Reproductive Strategies

SC.912.L.15.6 Classification

Multiple Choice

Organisms classified as fungi have unique characteristics. Which of the following characteristics is found only in organisms classified in the kingdom fungi?

• A. single cells without a nucleus

• B. multicellular with chloroplasts

• C. multicellular filaments that absorb nutrients

• D. colonies of single, photosynthetic cells that reproduce asexually

Explanation

These filaments, called hyphae extend into the fungi’s food source and absorb nutrients. Fungi are not able to make their own food. 

Multiple Choice

The diagram below represents possible evolutionary pathways of certain organisms. Which species is most closely related to species L?

• A. species E

• B. species F

• C. species G

• D. species I

Explanation

Species L and species N share the common ancestor, species F. 

Multiple Choice

Which kingdoms have photosynthetic organisms?

• A. fungi and plants

• B. fungi and protists

• C. protists and plants

• D. plants and animals

Explanation

Plant-like protists make their own food through photosynthesis, just like plants do. 

Multiple Choice

Some characteristics of a recently discovered organism are listed in the following table. Based on the given characteristics, this organism would be classified in which kindgom?

• A. eubacteria

• B. fungi

• C. plantae

• D. protista

Explanation

Fungi do not have chlorophyll because they are heterotrophs. Like us, they have to find food to eat and cannot make it themselves. Being non-motile (cannot move) this presents a challenge so they must produce spores to distribute themselves to new places where food sources are located.

Multiple Choice

In 1990, Carl Woese introduced the three domain system for classifying living things, after the advancement of DNA analysis allowed for a comparison of species genetic code. Which of the following is the best explanation for why domains were added to the previous system of classification?

• A. The old system of classification was wrong and needed to be corrected.

• B. New species are evolving too quickly to keep up with the old system of classification

• C. Domains have always been included, they were just made official recently.

• D. Some organisms, which were previously characterized together, were determined to be genetically very different.

Explanation

Using the analysis of RNA developed by Carl Woese, scientists are now able to classify living things based on genetic information instead of expressed characteristics. Genetic information is more specific and can give clues as to the evolutionary ancestry of organisms. 

SC.912.L.15.8 Origin of Life

Multiple Choice

One of the accepted scientific theories describing the origin of life on Earth is known as chemical evolution. According to this theory, which of the following events would need to occur first for life to evolve?

• A. onset of photosynthesis

• B. origin of genetic material

• C. Synthesis of organic molecules

• D. formation of the plasma membrane

Explanation

During chemical evolution, organic molecules were synthesized by individual elements. All living things are made from organic molecules, so the presence of these molecules is required for life to exist. 

Multiple Choice

Which types of organisms developed first due to the early environmental conditions on Earth?

• A. prokaryotic and aerobic

• B. prokaryotic and anaerobic

• C. eukaryotic and aerobic

• D. eukaryotic and anaerobic

Explanation

Prokaryotic organisms are single-celled and would have evolved first. Since atmospheric oxygen was not initially present on Earth, the ability to use anaerobic respiration to produce energy would have been necessary for the first living organisms. 

Multiple Choice

The Miller-Urey experiment of 1953 was designed to test the hypothesis that lightning supplied the energy needed to turn atmospheric gases into organic molecules such as amino acids. Which of the following describes why the Miller-Urey theory is widely accepted today?

• A. Amino acids spontaneously form from molecules in the atmosphere today.

• B. Organic molecules are present today in extremely high concentrations.

• C. The process of synthesizing organic molecules from a mixture of gases has been successfully modeled in the laboratory.

• D. No other alternative hypotheses have been introduced.

Explanation

The Miller-Urey experiments have been tested many times in the laboratory and organic molecules have continued to be successfully formed from mixtures of gases. 

Multiple Choice

The diagram below shows a proposed theory of the origin of eukaryotic cells, called endosymbiosis.Which of the following explains why cells that contained mitochondria-like organelles had an evolutionary advantage?

• A. They were able to photosynthesize

• B. They had more DNA

• C. They were able to make more use of available energy

• D. They were immune to bacterial invasion.

SC.912.L.15.13 Natural Selection

Multiple Choice

Over time, the climate of an island became drier, which resulted in changes to the populations of various island finch species. Finch populations with a certain beak shape thrived, while those not having that beak shape decreased. Which of the following describes a necessary condition for these changes in the finch populations to occur?

• A. fewer mutations

• B. limited food resources

• C. limited beak variations

• D. overproduction of offspring

Explanation

Limited resources are a major driving factor for natural selection. Since there was not enough food for all of the finches, the finches that had beaks which allowed them to get food more easily were more likely to survive and reproduce. 

Multiple Choice

Which of these would have the least effect on natural selection in a subspecies of giraffes that is geographically isolated from other subspecies of giraffes?

• A. available niches

• B. existing predators

• C. chromosome number

• D. available food resources

Explanation

Chromosome number is not a factor that influences natural selection. The other three choices represent factors that drive the process of natural selection. 

Multiple Choice

Mutations within a DNA sequence are

• A. natural processes that produce genetic diversity

• B. natural processes that always affect the phenotype

• C. unnatural processes that always affect the phenotype

• D. unnatural processes that are harmful to genetic diversity

Explanation

Random mutations in DNA provide genetic variation in a population of species and allow for natural selection to occur.

Multiple Choice

Which of the following best illustrates natural selection?

• A. An organism with favorable genetic variations will tend to survive and breed successfully.

• B. A population monopolizes all of the resources in its habitat, forcing other species to migrate.

• C. A community whose members work together utilizing all existing resources and migratory routes.

• D. The largest organisms in a species receive the only breeding opportunities.

Explanation

A. An organism with favorable genetic variations will tend to survive and breed successfully.

Multiple Choice

A small population of chimpanzees lives in a habitat that undergoes no changes for a long period. How will genetic drift probably affect this population?

• A. It will accelerate the appearance of new traits.

• B. It will promote the survival of chimpanzees with beneficial traits.

• C. It will increase the number of alleles for specific traits.

• D. It will reduce genetic diversity.

Explanation

Genetic drift is a change in the frequency of alleles due to change. Typically, genetic drift decreases genetic diversity in a population.

Multiple Choice

A small portion of the population that is geographically isolated from the rest of the population runs the risk of decreased.

• A. genetic drift

• B. mutation rate

• C. natural selection

• D. genetic variation

Explanation

Isolated populations run the risk of genetic drift due to decreased variation in the species. 

Multiple Choice

In his book On the Origin of the Species, Charles Darwin described how species change over time. Which of the following is NOT part of his observations that describes the mechanisms of natural selection?

• A. Organisms produce more offspring than can survive.

• B. Disease and natural disaster will limit population growth.

• C. Species today descended with modifications from ancestral species.

• D. Organisms with advantages will survive and reproduce.

Explanation

This answer represents evolution as a whole, not the process of natural selection.

Multiple Choice

Theodosius Dobzhansky discovered that successful species tend to have a wide variety of genes that do not appear to be useful to the species in its present environment. What did this discovery help explain about genetics and the changes that occur in a species over time?

• A. Environments with more organisms tend to have more successful species.

• B. Species with greater genetic diversity adapt more easily to changing environments.

• C. Changing environments prevent species from adapting and surviving.

• D. Species in a stable environment are more resistant to a changing environment.

Explanation

Greater genetic diversity allows for a wide range of environmental changes to occur without harming the population of organisms. 

SC.912.L.16.1 Genetics

Multiple Choice

Hemophilia is a sex-linked, recessive trait. Which of the following describes the probability of hemophilia in the offspring of a man who does not have hemophilia and a woman whose father is a hemophiliac?

• A. Each of their sons will have hemophilia.

• B. None of their daughters will have hemophilia.

• C. Their sons have a 25% chance of having hemophilia

• D. There is a 50% chance that their daughters will have hemophilia.

Explanation

Sex-linked traits are only present on sex chromosomes. Hemophilia is an X-linked chromosome so a father who does not have hemophilia must donate a non-hemophilia gene on the X chromosome he contributes to his daughter. For a girl to have a sexlinked condition, both of her X chromosomes have to have the allele for that condition

Multiple Choice

Alleles for the A and B blood cell antigens are codominant. The condition where no antigens are present on the blood cells (type O blood) is a recessive trait. Which set of parents can most likely produce a child with type O blood?

• A. one parent with type AB blood, and the other parent with type A blood

• B. one parent with type AB blood and the other parent with type O blood

• C. one parent with heterozygous type A blood, and the other parent with type O blood

• D. one parent with homozygous type A blood, and the other parent with homozygous type B blood

Explanation

In order for a recessive condition to be expressed, the individual must have two recessive alleles, one from the mother and one from the father. C is the only condition in which both parents possess an O allele to pass on to the offspring. 

Multiple Choice

One of the parents of a child has phenylketonuria (PKU), which is caused by recessive alleles. The other parent does not have the PKU alleles. What is the chance that the couple will have a child with phenylketonuria?

• A. 0%

• B. 50%

• C. 75%

• D. 100%

Explanation

For a recessive condition to be passed on, the offspring must inherit one allele for that condition from each parent. In this case, the father has no PKU alleles to pass on to the child, so even if the mother passes one on, it will not be expressed.

Multiple Choice

Hitchhiker's thumb (H) is dominant to no hitchhiker's thumb (h). A woman who does not have hitchhiker's thumb marries a man who is heterozygous for hitchhiker's thumb. What is the probable genotypic ratio of their children?

• A. 0% Hh: 100% hh

• B. 50% Hh: 50% hh

• C. 75% Hh: 25% hh

• D. 100% Hh: 0% hh

Multiple Choice

This diagram shows a pedigree for a recessive genetic disorder.What is the genotype of individual 6?

• A. XHXH

• B. XHXh

• C. XHY

• D. XhY

Explanation

Individual 6 is the offspring of individuals 1 and 2. Males are always represented with squares. If the disorder is recessive, the Father’s genotype must be Xh Y for the disorder to be expressed. Because the condition is expressed in the son (individual 6), we can infer that the mother’s genotype is heterozygous (XHXh ) because she must have contributed an X chromosome with the allele for the gene to her son, but did not have the condition herself. Individual 6 has the genotype Xh Y.

Multiple Choice

This diagram shows a diploid cell with two pairs of homologous chromosomes. Due to independent assortment, what is the possible genetic make-up of gametes produced by this organism?

• A. SsTt

• B. Ss, Tt

• C. S, s, T, t

• D. ST, St, sT, st

Explanation

Gametes are haploid and contain only half of the number of chromosomes of the parent cells (one of each chromosome type).

Multiple Choice

The table lists the trials for fruit color where allele R exhibits incomplete dominance over allele R'. Heterozygous fruit have orange phenotypes. What percent of offspring are expected to have an orange phenotype if the parent plants are orange (RR') and yellow (R'R')?

• A. 25%

• B. 50%

• C. 75%

• D. 100%

Multiple Choice

Mendel hypothesized that reproductive cells have only one factor for each inherited trait. This hypothesis is supported by which observation?

• A. Haploid cells are produced by mitosis.

• B. Diploid cells are produced by mitosis.

• C. Haploid cells are produced by meiosis.

• D. Diploid cells are produced by meiosis.

Explanation

Although each cell in the human body has two copies of each chromosome with one allele for each trait on them, the gametes (egg and sperm) have only one copy of each chromosome with one allele for each trait. 

Multiple Choice

A human baby boy inherits a recessive allele from his mother. In which circumstance would he most likely show the trait coded for by the recessive allele?

• A. The baby inherits the dominant allele from his father.

• B. The allele is on an autosomal chromosome and the baby is a twin.

• C. The allele is on the X chromosome

• D. The allele is on the Y chromosome.

Explanation

Traits coded for on the X chromosome will always be expressed in males because there is no counterpart allele to mask the expression. Boys have XY genotype and girls have XX genotype.