Penn Foster Biology Proctored Exam

Penn Foster Biology Proctored Exam | – Actual Exam Questions & Verified Correct Answers (200 Qs) | A Grade Guaranteed | Comprehensive Biology Mastery Introduction This resource features 200 actual and verified questions from the latest version of the Penn Foster Biology Proctored Exam. Fully aligned with the – essential concepts across molecular, cellular, and organismal biology, ensuring students are well-prepared to achieve top scores and earn an A grade with confidence.

Topics Covered:

• Cell Structure and Function • Genetics and Heredity • DNA, RNA, and Protein Synthesis • Photosynthesis and Cellular Respiration • Biological Classification and Taxonomy • Evolution and Natural Selection • Human Anatomy and Physiology • Ecology and Environmental Science • Microbiology and Biotechnology • Plant Biology and Reproduction All correct answers are marked in bold and green. Where applicable, concise explanations are provided to reinforce core biology principles and clarify high-yield exam content.Exam Questions and Answers Question 1

Question: What is the primary source of energy for Earth's climate system?

• Geothermal energy
• Solar radiation
• Tidal forces
• Fossil fuels

Rationale: Solar radiation drives Earth's climate system by providing energy for atmospheric and oceanic processes.Question 2 Question: Which organelle is responsible for protein synthesis in eukaryotic cells?

• Golgi apparatus
• Ribosome
• Mitochondrion
• Lysosome

Rationale: Ribosomes, found in the cytoplasm or on the rough ER, synthesize proteins by translating mRNA. 1 / 4

Question 3 Question: In a Punnett square for a monohybrid cross (Aa × Aa), what is the probability of an offspring with the homozygous recessive genotype?

A) 50%

B) 25%

C) 75%

D) 100%

Rationale: A monohybrid cross (Aa × Aa) yields a 1:2:1 genotypic ratio, with 25% chance of aa (homozygous recessive).Question 4 Question: What molecule carries genetic information from DNA to the ribosome for protein synthesis?

• tRNA
• mRNA
• rRNA
• siRNA

Rationale: mRNA is transcribed from DNA and carries the genetic code to ribosomes for translation.Question 5 Case Study: A plant is grown in low-light conditions and exhibits elongated stems and small leaves.

Question: What is this phenomenon called? Select all that apply.

• Phototropism
• Etiolation
• Gravitropism
• Shade avoidance

Rationale: Etiolation and shade avoidance describe plants adapting to low light with elongated stems and reduced leaf growth.Question 6 Question: Which process converts light energy into chemical energy in chloroplasts?

• Cellular respiration
• Photosynthesis
• Fermentation
• Glycolysis

Rationale: Photosynthesis uses light energy to produce glucose in chloroplasts, primarily in the thylakoid membranes.Question 7

Question: What is the primary function of the mitochondria?

• Protein synthesis
• ATP production
• Lipid storage
• DNA replication

Rationale: Mitochondria generate ATP via oxidative phosphorylation in cellular respiration.Question 8 Question: In which phase of mitosis do sister chromatids separate? 2 / 4

• Prophase
• Anaphase
• Metaphase
• Telophase

Rationale: During anaphase, sister chromatids are pulled apart to opposite poles of the cell.Question 9

Question: Which taxonomic level is the most inclusive?

• Species
• Domain
• Genus
• Family

Rationale: Domain is the highest taxonomic rank, encompassing Archaea, Bacteria, and Eukarya.Question 10 Question: What is the primary source of genetic variation in sexually reproducing organisms?

• Mitosis
• Meiosis
• Binary fission
• Transcription

Rationale: Meiosis introduces genetic variation through crossing over and independent assortment.Question 11 Question: Which molecule is the final electron acceptor in the electron transport chain of cellular respiration?

• Glucose
• Oxygen
• Carbon dioxide

D) NADH

Rationale: Oxygen accepts electrons in the electron transport chain to form water, driving ATP production.Question 12 Question: What is the term for a change in a population’s allele frequencies over generations?

• Genetic drift
• Evolution
• Gene flow
• Mutation

Rationale: Evolution is defined as a change in allele frequencies in a population over time.Question 13 Question: Which part of the human respiratory system is responsible for gas exchange?

• Trachea
• Alveoli
• Bronchi
• Diaphragm 3 / 4

Rationale: Alveoli are the sites of gas exchange, where oxygen enters the blood and carbon dioxide is removed.Question 14 Question: In ecology, what term describes organisms that produce their own food?

• Heterotrophs
• Autotrophs
• Decomposers
• Carnivores

Rationale: Autotrophs, such as plants, produce their own food via photosynthesis or chemosynthesis.Question 15 Case Study: A population of bacteria develops resistance to an antibiotic after exposure.

Question: Which mechanism is most likely responsible? Select all that apply.

• Genetic drift
• Natural selection
• Gene flow
• Mutation

Rationale: Mutations create resistant alleles, and natural selection favors resistant bacteria under antibiotic pressure.Question 16

Question: What is the role of RNA polymerase in transcription?

• Breaks down RNA
• Synthesizes RNA from DNA
• Translates mRNA
• Replicates DNA

Rationale: RNA polymerase synthesizes RNA by reading a DNA template during

transcription.Question 17 Question: Which plant tissue transports water and nutrients from roots to leaves?

• Phloem
• Xylem
• Epidermis
• Parenchyma

Rationale: Xylem transports water and minerals upward from roots to leaves in plants.Question 18 Question: What is the primary source of energy for ATP production in anaerobic respiration?

• Oxygen
• Glucose
• Light
• Nitrogen

Rationale: Glucose is broken down in anaerobic respiration to produce ATP without oxygen.Question 19

Question: Which type of symbiotic relationship benefits both species?

• Parasitism
• / 4