WorksheetsMCAS Review
Total questions: 49
Worksheet time: 25mins
Adélie penguins are well adapted to Antarctica’s cold climate. They eat fish off the coast of Antarctica and build nests on land. The average temperature in Antarctica has been increasing. Scientists claim that if this trend continues, it may have a negative effect on the penguins’ ability to survive.
Which of the following best supports the scientists’ claim?
Melting ice will decrease the concentration of salt in the ocean.
Increasing ocean temperatures will reduce fish population sizes.
Increasing air temperatures will allow more plant species to grow.
Melting snow will increase the size of the area where the penguins live.
In some types of cattle, the allele for a spotted coat (s) is recessive to the allele for a solid-colored coat (S). A cow with a spotted coat is mated with a bull that is homozygous for a solid coat.
What percentage of the offspring are expected to have solid coats?
100%
75%
50%
25%
The diagram represents a process that occurs in chromosomes during meiosis. The letters represent different genes with different alleles.
This process is important for the survival of a species because it helps introduce which of the following into a population?
dominant genes
gene mutations
genetic variation
polygenic traits
Scientists developed an antibiotic to fight harmful bacteria that cause infections. After several years of use, the antibiotic became less effective.
Which of the following caused the antibiotic to become less effective?
Bacteria that were resistant to the antibiotic survived to produce more resistant bacteria.
Bacteria that were not resistant to the antibiotic began to produce resistant bacteria through meiosis.
Bacteria that were not resistant to the antibiotic learned how to protect themselves from the antibiotic.
Bacteria that were resistant to the antibiotic lost their resistance with repeated exposure to the antibiotic.
Which of the following is an example of polygenic inheritance?
Two alleles code for a mixture of black and white feathers in chickens.
Several genes with different alleles contribute to a range of eye colors in fruit flies.
A rabbit can have one of four fur coat colors because of four alleles for a single gene.
A plant that has the allele for red flowers and the allele for white flowers produces pink flowers.
A professional athlete often runs long distances. Some of the steps that enable the athlete to run are shown.
Step 1: The athlete eats food before running.
Step 2: The food is broken down into nutrients.
Step 3: Usable energy is produced from the nutrients.
Step 4: The athlete’s muscles use the energy to contract.
Which of the following provides a more accurate step than the one shown?
Step 1: The athlete completely digests food while chewing.
Step 2: The only food molecules broken down into nutrients are fat molecules.
Step 3: Usable energy is produced from the nutrients during cellular respiration.
Step 4: The athlete’s muscles produce glucose when they use energy to contract.
A professional athlete often runs long distances. Some of the steps that enable the athlete to run are shown.
Step 1: The athlete eats food before running.
Step 2: The food is broken down into nutrients.
Step 3: Usable energy is produced from the nutrients.
Step 4: The athlete’s muscles use the energy to contract.
The athlete begins a long-distance run. As the athlete runs, their body produces more _____________.
amino acids.
carbon dioxide.
nitrogen.
oxygen.
A gamete of a domestic cat has 19 chromosomes. A student claims that a body cell of the cat contains 38 chromosomes. Which of the following best describes the student’s claim?
The claim is correct because a sperm cell fertilizes an egg cell, resulting in a cell with 38 chromosomes.
The claim is incorrect because the egg and sperm cells have a total of 19 chromosomes when they combine.
The claim is incorrect because the egg and sperm cells divide and have a total of 76 chromosomes when they combine.
The claim is correct because a sperm cell carries all of the chromosomes and passes them to the egg cell, resulting in 38 chromosomes.
The pupfish is a type of fish that lives in small pools of water in the desert. A researcher studying desert ecosystems found that crayfish and mosquitofish had been introduced into some of these desert pools. After making this discovery, the researcher created three test ponds and put the following in each pond:
Pond 1: pupfish only
Pond 2: pupfish and crayfish
Pond 3: pupfish and mosquitofish
The researcher counted the number of each type of organism in each pond once a month for four months.
Which of the following describes what the researcher was most likely studying?
how immigration affects population size
how to increase biodiversity in the desert
how invasive species affect native species
how to decrease competition between predators
An Antarctic marine food web is shown.
An increase in the population size of which of the following will lead to the greatest decrease in the squid population?
algae
cod
penguins
zooplankton
Keratin is a protein found in hair, nails, and feathers of animals. Which of the following elements is most abundant in keratin?
aluminum
carbon
iron
zinc
The American toad and the Fowler’s toad are closely related and found in the eastern part of North America. American toads breed in early summer, and Fowler’s toads breed in late summer. The two types of toads have produced fertile offspring when bred in the laboratory. They do not produce fertile offspring in the wild.
Which of the following best explains why these two types of toads do not produce fertile offspring in the wild?
The diets of each type of toad are changing.
The genes in the gametes in each type of toad are different.
An increase in gene flow occurred between the two types of toads.
Behavioral differences between the two types of toads caused reproductive isolation.
The CFTR gene is responsible for regulating the flow of water across cell membranes that produce mucus, sweat, saliva, and tears. Mucus is the substance that moistens and protects the lining of airways in the lungs, the digestive system, and other tissues in the body. An inherited condition is caused by a mutation in the CFTR gene. People with the CFTR mutation often experience digestive problems, which can result in weight loss.
Which of the following most likely occurs as a result of the digestive problems?
A large amount of sugar enters the bloodstream.
A large amount of oxygen is released to body cells.
Many nutrients are not absorbed into the bloodstream.
Salt is not absorbed quickly enough by the large intestine.
The CFTR gene is responsible for regulating the flow of water across cell membranes that produce mucus, sweat, saliva, and tears. The pedigree shows which family members are affected by the CFTR mutation. For the person labeled 8 to have inherited the condition, the CFTR mutation must have been in the parents’ ______.
brain cells.
heart cells.
lung cells.
sex cells.
The CFTR gene is responsible for regulating the flow of water across cell membranes that produce mucus, sweat, saliva, and tears. An inherited condition is caused by a mutation in the CFTR gene. For people with this CFTR mutation, the cells that make mucus produce a very thick mucus, which builds up and leads to severe breathing problems, such as frequent coughing and respiratory infections. People with the CFTR mutation often experience breathing problems.
Which of the following is a direct result of these breathing problems?
The filtration of toxins by the liver is increased.
The transport of nutrients in the body is reduced.
The diffusion of oxygen into the bloodstream is reduced.
The production of carbon dioxide in the body is increased.
The CFTR mutation most often occurs when three nucleotides from the gene sequence are deleted. The DNA sequence without the mutation and the DNA sequence with the mutation are shown.
DNA sequence without mutation: TAG TAG AAA CCA CAA
DNA sequence with mutation: TAG TAA CCA CAA
Which of the following is the mRNA sequence for the DNA sequence without the mutation?
ATC ATC TTT GGT GTT
UAG UAG AAA CCA CAA
AUC AUC UUU GGU GUU
UUG UGG UUU CUA CUA
The CFTR mutation most often occurs when three nucleotides from the gene sequence are deleted. The DNA sequence without the mutation and the DNA sequence with the mutation are shown.
DNA sequence without mutation: TAG TAG AAA CCA CAA
DNA sequence with mutation: TAG TAA CCA CAA
The table shows the amino acids coded for by mRNA codons.
Based on the information, which amino acid is missing in the protein produced by the CFTR mutation?
Glu
Phe
Ser
Val
The condition caused by the CFTR mutation is controlled by a single gene with two alleles, D and d.
Based on the pedigree, identify the most likely inheritance pattern for the condition.
codominant
dominant
recessive
sex-linked
The graph shows how concentrations of dissolved oxygen (O2) and carbon dioxide (CO2) gases change in pond water on a warm, sunny day.
Based on the graph, which of the following best compares two processes occurring between 6 a.m. and 6 p.m.?
The rate of transpiration is greater than the rate of combustion.
The rate of combustion is greater than the rate of transpiration.
The rate of photosynthesis is greater than the rate of cellular respiration.
The rate of cellular respiration is greater than the rate of photosynthesis.
The table shows the percentages of DNA similarity among four animal species.
Use the information in the table to determine the evolutionary relatedness among the four species. Which cladogram shows how the species are related?
A student drew a model to represent the carbon cycle, as shown. The arrows represent four processes in the carbon cycle.
Select two changes the student could make to improve the model.
Draw an arrow from the fossil fuels pointing to the factory, since fossil fuels provide energy to the factory.
Draw an arrow from the forest pointing to the carbon dioxide in the atmosphere, since plants perform photosynthesis.
Draw arrows from the forest and animals pointing to the decomposers, since decomposers break down dead organisms.
Draw an arrow from the carbon dioxide in the atmosphere pointing to the animals, since animals perform cellular respiration.
An adult human body contains trillions of cells. Body cells go through the stages of the cell cycle. A diagram of the cell cycle is shown.
Choose two events that occur during the interphase stage of the cell cycle.
chromosomes divide
chromosomes replicate
cell grows
spindle fibers form
As an ant population moves across the forest floor, flying insects move away. Some birds follow the ants, catching and eating the flying insects.
Which of the following best explains the relationship between the birds and the ants?
It is commensal because it benefits the birds and has no effect on the ants.
It is commensal because it benefits the ants and has no effect on the birds.
It is parasitic because it benefits the birds and has a negative effect on the ants.
It is parasitic because it benefits the ants and has a negative effect on the birds.
The birth rate is about the same as the death rate in population X. Which of the following changes would be expected to increase the size of population X the most?
a large increase in both the emigration rate and the immigration rate
a large decrease in both the emigration rate and the immigration rate
a large decrease in the emigration rate and a large increase in the immigration rate
a large increase in the emigration rate and a large decrease in the immigration rate
In a laboratory, cell parts were separated using a centrifuge. The table shows four samples of cell parts that were isolated.
After the cell parts were isolated, RNA and amino acids were added to each sample. After some time, the samples were tested for proteins.
Which sample most likely contained newly made proteins?
sample A
sample B
sample C
sample D
The flamingo is a type of bird. Young flamingos have white and gray feathers. By the time they are 3–6 years old, their feathers have become pink. The pink color is caused by the flamingo’s diet. Flamingos eat shrimp, which have red and orange pigments. When a flamingo stops eating shrimp, its feathers lose their pink color over time.
Which of the following best describes the cause of feather color in flamingos at different ages?
Pink feather color in adult flamingos and white and gray feathers in young flamingos are both most directly caused by genetic factors.
Pink feather color in adult flamingos and white and gray feathers in young flamingos are both most directly caused by environmental factors.
Pink feather color in adult flamingos is most directly caused by genetic factors and white and gray feathers in young flamingos are most directly caused by environmental factors.
Pink feather color in adult flamingos is most directly caused by environmental factors and white and gray feathers in young flamingos are most directly caused by genetic factors.
The flamingo is a type of bird. Young flamingos have white and gray feathers. By the time they are 3–6 years old, their feathers have become pink. The pink color is caused by the flamingo’s diet. Flamingos eat shrimp, which have red and orange pigments. When a flamingo stops eating shrimp, its feathers lose their pink color over time.
The pink color of flamingo feathers demonstrates that the phenotype for feather color ________, and the genotype for feather color ________.
changes, changes
changes, stays the same
stays the same, changes
stays the same, stays the same
A particular human disease results from mutations in a nucleotide sequence that encodes a protein responsible for transporting ions across the cell membrane. The sequence is more than 6000 nucleotides long, and there are many known mutations that can cause the disease. One example is a mutation at nucleotide 1609, which results in a stop codon rather than a codon for an amino acid.
Which of the following describes the expected result of this mutation?
The transport of ions across the membrane stops because the protein is nonfunctional.
The transport of ions across the membrane slows down because the protein is smaller than it should be.
The transport of ions across the membrane speeds up because the protein is produced faster than it should be.
The transport of ions across the membrane occurs in the opposite direction because the protein has an irregular shape.
Which of the following is the best example of speciation due to geographic isolation?
A coral species casts all of its gametes out into the water when conditions are right for reproduction.
Two groups of birds share a summer breeding habitat but migrate to different locations in Mexico for the winter.
A plant species produces seeds that stick to the fur of mammals and get distributed to distant locations to germinate.
Descendants of fruit flies that colonized the Hawaiian Islands from the mainland cannot successfully breed with mainland fruit flies.
A plant called downy thornapple stores its seeds in pods. The texture of the pods is genetically determined. The allele for spiny pods (S) is dominant to the allele for smooth pods (s). A plant that has smooth pods is crossed with a homozygous plant that has spiny pods.
What percentage of the offspring are expected to have smooth pods?
0%
25%
50%
100%
Which of the following describes how the liver interacts with the circulatory system?
It supplies oxygen to the blood.
It redirects blood flow in the body.
It produces hemoglobin for red blood cells.
It converts toxic compounds in blood to less toxic compounds.
Carolina chickadees are small birds found in the southeastern United States. The chickadees eat insects that feed only on native plants in their habitat.
Which of the following would most likely occur if an invasive plant species were introduced into the chickadees’ habitat?
The chickadee population size would increase because more insects would be available to eat.
The chickadee population size would remain unchanged because chickadees do not eat the invasive plants.
The chickadee population size would decrease because the invasive plants would outcompete native plants.
The chickadee population size would increase because the number of producers in the ecosystem would increase.
Pronghorn antelope are herbivores that live in an area that includes much of the western United States. Wild horses and domestic sheep that also live in the area eat the same types of grasses as the pronghorn antelope. Coyotes and bobcats in the area prey on the antelope.
Which of the following would most likely increase the carrying capacity for the pronghorn antelope?
a ban on hunting bobcats in the area
a new law that allows more sheep to be raised in the area
a dry winter that decreases the number of plants that grow in the area
a viral disease that decreases the population size of the wild horses in the area
The diagram represents two cell processes.
What processes are represented in the diagram?
Process 1 is translation and process 2 is replication.
Process 1 is mitosis and process 2 is crossing over.
Process 1 is growth and process 2 is reproduction.
Process 1 is meiosis and process 2 is fertilization.
Crayfish are freshwater crustaceans that look like small lobsters. They are found in many parts of the world. The marbled crayfish was first discovered in an aquarium in 1995 and was not originally found in the wild. Scientists think that the marbled crayfish evolved from another type of crayfish, the slough crayfish.
Which of the following best supports the scientists’ hypothesis that the slough crayfish is an ancestor of the marbled crayfish?
Slough crayfish and marbled crayfish have the same number of legs.
Slough crayfish and marbled crayfish can be found in the same habitats.
The genome of the slough crayfish is very similar to the genome of the marbled crayfish.
The ecological role of the slough crayfish is very similar to the ecological role of the marbled crayfish.
Marbled crayfish live in fresh water. Fresh water has a low concentration of sodium compared to the concentration inside crayfish cells.
Which of the following best describes the movement of sodium and water between a crayfish cell and its freshwater environment?
Both sodium and water move into the cell.
Both sodium and water move out of the cell.
Sodium moves into the cell, and water moves out of the cell.
Sodium moves out of the cell, and water moves into the cell.
Marbled crayfish live in fresh water. Fresh water has a low concentration of sodium compared to the concentration inside crayfish cells.
Which of the following describes how cell membranes of crayfish cells help to maintain homeostasis of the crayfish?
The cell membranes allow only glucose into the cell.
The cell membranes allow only certain waste products to leave the cell.
The cell membranes allow only certain materials into and out of the cell.
D The cell membranes allow only proteins to leave the cell and only oxygen to enter the cell.
Crayfish are freshwater crustaceans that look like small lobsters. They are found in many parts of the world. The marbled crayfish
the marbled crayfish reproduces asexually.
The energy needed for cell growth in marbled crayfish is provided by the process of ______________.
active transport.
cellular respiration.
mitosis.
transpiration.
In 2003, the marbled crayfish was introduced to Madagascar. Since then, it has spread quickly across Madagascar and lives in the same areas where several native crayfish species live. The native crayfish species reproduce sexually, the marbled crayfish reproduce asexually. The map shows the range of marbled crayfish across Madagascar in 2007 and 2018.
A native Madagascar crayfish population may be better able to survive than the marbled crayfish population if a disease were introduced into their habitat. Which of the following best explains why a native Madagascar crayfish population may be better able to survive if a disease were introduced?
Native Madagascar crayfish reproduce sexually and have less genetic variation.
Native Madagascar crayfish reproduce sexually and have more genetic variation.
Native Madagascar crayfish reproduce slowly and will be less exposed to the disease.
Native Madagascar crayfish reproduce quickly and will be less exposed to the disease.
An aquatic food web with the marbled crayfish is shown.
Identify the ecological role of the marbled crayfish.
decomposer
producer
primary consumer
secondary consumer
An aquatic food web with the marbled crayfish is shown.
How would a large increase in the size of the marbled crayfish population affect the size of the dragonfly population.
decrease
increase
no change
An aquatic food web with the marbled crayfish is shown.
Identify the organism in the food web that has the most available energy.
Dragonfly larvae
Mosquito
Algae
Common carp
Marbled crayfish
Which of the following explains why a human infant is genetically similar to, but not identical to, its mother?
The infant’s cells undergo mitosis as it develops from fertilization to birth.
The set of chromosomes that an infant inherits is determined by natural selection.
The infant’s genetic material is translated by both the mother’s and the father’s cells.
Half of the infant’s genetic material comes from the mother and half comes from the father.
Milk contains a high concentration of the carbohydrate lactose. What is the basic structure of lactose?
two monosaccharides joined together
a chain of amino acids in a helix shape
two fatty acids joined to a phosphate group
a chain of alternating sugar and phosphate groups
A strawberry farmer makes the crosses described in the table.
Which of the following would be expected to produce the most offspring with the heterozygous genotype?
crossing two offspring from cross 1
crossing two offspring from cross 3
crossing an offspring from cross 1 with an offspring from cross 2
crossing an offspring from cross 1 with an offspring from cross 3
In April 2009, a new type of influenza virus that became known as 2009 H1N1 was reported in the United States. The number of reported cases grew rapidly. By June 2009, 70 countries were reporting outbreaks of the virus.
Which of the following was most responsible for the rapid spread of the 2009 H1N1 virus?
The virus often killed a host cell after infecting the cell.
The virus reproduced only before entering and infecting a host cell.
The genetic material of a host cell was used when new viral particles were produced.
Only a few simple structures needed to be made when new viral particles were produced by a host cell.
In April 2009, a new type of influenza virus that became known as 2009 H1N1 was reported in the United States. The number of reported cases grew rapidly. By June 2009, 70 countries were reporting outbreaks of the virus.
Which of the following best explains why new types of influenza viruses, such as 2009 H1N1, can develop?
Rapid reproduction allows mutations to be introduced into viral populations.
When viruses reproduce using many cell parts, they are able to develop new types of organelles.
Viruses travel slowly from one host to another and are able to break down more organic material.
The genetic material of viruses is constantly changed by environmental factors like radiation, and the viruses are able to grow larger.
A student is studying how flowering plants and insects affect oxygen (O2) and carbon dioxide (CO2) concentrations in the air. Identify the cellular process performed only by the flowering plants that affects the concentrations of O2 and CO2 in the air.
Transcription
Photosynthesis
Decomposition
Cellular respiration
A student is studying how flowering plants and insects affect oxygen (O2) and carbon dioxide (CO2) concentrations in the air.
Identify the cellular process performed by both the flowering plants and the insects that affects the concentrations of O2 and CO2 in the air.
Translation
Cellular respiration
Photosynthesis
Mitosis
