CLEP Biology Exam Prep 2026 practice questions and answers. Tap an option to test yourself — you'll see the correct answer and a plain-English explanation for every question. Free, no login.
Q1The following statements about the adaptation of animals to colder climates are all true, except:
✓ Correct answer: D. Animals lost much of their fur as they adapted to colder climates
Answer: Animals lost much of their fur as they adapted to colder climates In colder climates, animals generally evolved to grow thicker fur, not lose it, to maintain body heat. Other adaptations include thicker fat layers and hibernation behaviors.
Q2Given the different habitats in aquatic ecosystems, identify the main groups of algae based on their predominant pigmentation and structure. Algae Type Pigmentation Structure Green Algae Chlorophyll Varied forms, from unicellular to multicellular Red Algae Phycoerythrin Mostly multicellular Brown Algae Fucoxanthin Predominantly large and multicellular
✓ Correct answer: C. Green Algae = Chlorophyll; Red Algae = Phycoerythrin; Brown Algae = Fucoxanthin
Answer: Green Algae = Chlorophyll; Red Algae = Phycoerythrin; Brown Algae = Fucoxanthin Green algae primarily contain chlorophyll, which gives them their characteristic green color. They can be found in various forms, from single-celled organisms to complex multicellular structures. Red algae are predominantly multicellular, and their red pigmentation is due to phycoerythrin, which allows them to photosynthesize in deeper waters. Brown algae, like the well-known kelps, are generally large and multicellular, characterized by their brown color due to the presence of fucoxanthin.
Q3Which of the following characteristics might be observed in a tundra biome? Characteristic Description i Extremely low temperatures ii High biodiversity iii Permafrost present iv High precipitation v Short growing seasons vi Dense tree cover
✓ Correct answer: E. i, iii, and v
Answer: i, iii, and v. The tundra biome is characterized by extremely low temperatures, presence of permafrost, and short growing seasons. Biodiversity is typically low due to harsh conditions, and dense tree cover is absent.
Q4In a population of plants, a trait such as flower color can be influenced by environmental conditions. What kind of genetic trait is this considered to be?
✓ Correct answer: D. Multifactorial
Multifactorial traits are those where environmental factors as well as genetic factors contribute to the phenotype. Unlike purely autosomal traits, which are determined by a single gene, multifactorial traits may display variability due to environmental conditions.
Q5In a population of wildflowers, the color of the petals is determined by a simple recessive genetic trait. Based on this trait, which generalization about the genetic appearance of flower color is most likely to be true?
✓ Correct answer: E. Homozygous recessive flowers display the recessive color, while heterozygous flowers do not.
Answer: Homozygous recessive flowers display the recessive color, while heterozygous flowers do not. In simple recessive genetic traits, two different alleles can occur. The recessive trait will only be displayed in the phenotype when both alleles are recessive (homozygous recessive). If the organism is heterozygous, the dominant trait will mask the recessive trait, meaning the recessive color will not be displayed.
Q6Which of the following is the most accurate example of migration behavior?
✓ Correct answer: C. Monarch butterflies travel thousands of miles from North America to central Mexico for the winter
Answer: Monarch butterflies travel thousands of miles from North America to central Mexico for the winter. Migration involves long-distance seasonal movement to a different territory. The earthworm example is an adaption to environmental conditions, the cheetah example is a hunting tactic, the squirrel storing food is resource management, and the chameleon changing color is camouflaging.
Q7In a Bb x Bb cross involving two heterozygous rabbits, what are the genotypes of the offspring in terms of coat color?
✓ Correct answer: E. 25% BB (homozygous dominant), 50% Bb (heterozygous), 25% bb (homozygous recessive)
Answer: 25% BB (homozygous dominant), 50% Bb (heterozygous), 25% bb (homozygous recessive) To determine the genotypic ratios, draw a Punnett square. An individual is homozygous if the alleles are identical and heterozygous if not. Dominant alleles are represented by a capital letter while recessive alleles use a lowercase letter.
Q8In a population of mice, some individuals have brown fur, while others have white fur. A mouse with brown fur and a mouse with white fur possess different __________ of the same gene responsible for fur color.
✓ Correct answer: D. Alleles
Answer: Alleles Alleles are different forms of the same gene, found at the same loci on the same chromosome. These alleles can result in variations in traits, such as fur color in mice.
Q9For a study in an aquatic ecosystem, identify which of the following are examples of density-independent factors affecting fish populations: Statement i. Introduction of a new fish predator in the ecosystem ii. Toxic chemicals spilled into the water iii. Hurricanes causing widespread habitat destruction iv. Seasonal temperature changes leading to water stratification v. Increased competition for nesting sites
✓ Correct answer: A. ii, iii, and iv
Answer: ii, iii, and iv. Density-independent factors are abiotic factors that can impact population size irrespective of the population density. In this context, the spill of toxic chemicals, hurricanes, and seasonal temperature changes are abiotic factors, whereas a new predator and increased competition are biotic, density-dependent factors.
Q10Consider the following components as factors influencing the process of natural selection in a population: Component Description i. Variation in traits Differences in traits among individuals ii. Selective pressure Environmental factors that affect survival iii. Genetic mutations Changes in DNA sequence iv. Reproductive success Ability to produce offspring v. Gene inheritance Passing genes to the next generation Which of these components are essential for natural selection to occur?
✓ Correct answer: E. i, ii, and iv
Answer: i, ii, and iv Variation in traits, selective pressure, and reproductive success are key components of natural selection. Genetic mutations and gene inheritance are mechanisms that contribute to these processes, but they are not required components for natural selection itself.
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