Bio 189 Final Exam- UNLV Exam
Questions and Answers A+ Grade
2026/2027 | Complete Biology Final
Exam Study Guide
1. Chief unifying principle of biology
CORRECT ANSWER: Evolution
Explanation:
Evolution is considered the chief unifying principle of biology because it explains the similarities
and differences among all living organisms and how life has changed over time.
2. Evolution
CORRECT ANSWER: Gradual modification of populations of organisms over time so as to
be better adapted to their environment
Explanation:
Evolution occurs when inherited traits in a population change over many generations, allowing
organisms to survive and reproduce more successfully.
3. Change in genetically determined phenotypic traits of a population over successive
generations
CORRECT ANSWER: Evolution
Explanation:
Evolution occurs when the frequency of alleles in the gene pool changes over generations.
4. Modification often results in
, CORRECT ANSWER: Development of new species
Explanation:
Accumulated changes over time can cause populations to become so different that they form
separate species.
5. Common descent with modification
CORRECT ANSWER: One of the key principles of evolution
Explanation:
Groups of organisms can gradually change from ancestral species and eventually form new
species.
6. All life on Earth ultimately evolved from a
CORRECT ANSWER: Universal common ancestor
Explanation:
All living organisms share common genetic and biochemical characteristics because they
originated from an ancient common ancestor.
7. Natural selection
CORRECT ANSWER: A key principle of evolution where traits that provide survival and
reproductive advantages become more common in a population
Examples:
• Speed in cheetahs
• Intelligence in humans
Explanation:
Individuals with beneficial traits are more likely to survive and reproduce.
8. Adaptations
CORRECT ANSWER: Special traits that enable species to survive in different habitats
, Explanation:
Adaptations improve an organism’s ability to survive and reproduce in its environment.
9. Vestigial structures (evidence for evolution)
CORRECT ANSWER: Structures possessed by ancestors that are no longer useful but still
persist
Example:
Ostrich wings — birds have wings, but ostriches no longer use them for flight.
10. DNA as evidence for evolution
CORRECT ANSWER:
• All life contains the same four nucleotides: A, C, G, T
• All life uses RNA polymerase to transcribe DNA into mRNA
• The genetic code for translating mRNA into proteins is universal
Explanation:
The similarities in DNA and genetic processes support the idea that all organisms share common
ancestry.
11. Genes
CORRECT ANSWER: Segments of DNA that code for one or more proteins
12. Diploid
CORRECT ANSWER: Having two copies of each gene
Explanation:
Sexually reproducing organisms inherit one copy of each gene from each parent.
13. Different versions of genes are called
Questions and Answers A+ Grade
2026/2027 | Complete Biology Final
Exam Study Guide
1. Chief unifying principle of biology
CORRECT ANSWER: Evolution
Explanation:
Evolution is considered the chief unifying principle of biology because it explains the similarities
and differences among all living organisms and how life has changed over time.
2. Evolution
CORRECT ANSWER: Gradual modification of populations of organisms over time so as to
be better adapted to their environment
Explanation:
Evolution occurs when inherited traits in a population change over many generations, allowing
organisms to survive and reproduce more successfully.
3. Change in genetically determined phenotypic traits of a population over successive
generations
CORRECT ANSWER: Evolution
Explanation:
Evolution occurs when the frequency of alleles in the gene pool changes over generations.
4. Modification often results in
, CORRECT ANSWER: Development of new species
Explanation:
Accumulated changes over time can cause populations to become so different that they form
separate species.
5. Common descent with modification
CORRECT ANSWER: One of the key principles of evolution
Explanation:
Groups of organisms can gradually change from ancestral species and eventually form new
species.
6. All life on Earth ultimately evolved from a
CORRECT ANSWER: Universal common ancestor
Explanation:
All living organisms share common genetic and biochemical characteristics because they
originated from an ancient common ancestor.
7. Natural selection
CORRECT ANSWER: A key principle of evolution where traits that provide survival and
reproductive advantages become more common in a population
Examples:
• Speed in cheetahs
• Intelligence in humans
Explanation:
Individuals with beneficial traits are more likely to survive and reproduce.
8. Adaptations
CORRECT ANSWER: Special traits that enable species to survive in different habitats
, Explanation:
Adaptations improve an organism’s ability to survive and reproduce in its environment.
9. Vestigial structures (evidence for evolution)
CORRECT ANSWER: Structures possessed by ancestors that are no longer useful but still
persist
Example:
Ostrich wings — birds have wings, but ostriches no longer use them for flight.
10. DNA as evidence for evolution
CORRECT ANSWER:
• All life contains the same four nucleotides: A, C, G, T
• All life uses RNA polymerase to transcribe DNA into mRNA
• The genetic code for translating mRNA into proteins is universal
Explanation:
The similarities in DNA and genetic processes support the idea that all organisms share common
ancestry.
11. Genes
CORRECT ANSWER: Segments of DNA that code for one or more proteins
12. Diploid
CORRECT ANSWER: Having two copies of each gene
Explanation:
Sexually reproducing organisms inherit one copy of each gene from each parent.
13. Different versions of genes are called
