Font size
WorksheetsMCAS Practice Test #1
Total questions: 20
Worksheet time: 2hrs 40mins
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 variations
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.
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.
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.
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 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.
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.
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 table shows the amino acids coded for by mRNA.
Based on the information, which amino acid is missing in the protein produced by the CFTR mutation?
DNA sequence without mutation: TAG TAG AAA CCA CAA
DNA sequence with mutation: TAG TAA CCA CAA
Glu
Phe
Ser
Val
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.
