PSSA PSSA Life Science 2 — Questions and Answers
Question 1: What is the function of the nucleus in a cell?
- To produce energy for the cell
- To control the cell's activities and store DNA (Correct answer)
- To package proteins for export
- To regulate materials entering and leaving the cell
Correct answer: To control the cell's activities and store DNA
The nucleus serves as the control center of the cell, containing DNA and directing cellular activities.
Question 2: Which of the following best describes natural selection?
- Organisms intentionally change their traits to survive
- Organisms with favorable traits are more likely to survive and reproduce (Correct answer)
- All organisms in a population evolve at the same rate
- Random mutations always improve an organism's survival chances
Correct answer: Organisms with favorable traits are more likely to survive and reproduce
Natural selection is the process by which individuals with favorable traits survive and reproduce more successfully, passing those traits to offspring.
Question 3: What is the difference between a vertebrate and an invertebrate?
- Vertebrates live on land; invertebrates live in water
- Vertebrates have a backbone; invertebrates do not (Correct answer)
- Vertebrates reproduce sexually; invertebrates reproduce asexually
- Vertebrates are warm-blooded; invertebrates are cold-blooded
Correct answer: Vertebrates have a backbone; invertebrates do not
Vertebrates have a backbone (vertebral column), while invertebrates lack this internal skeletal structure.
Question 4: Which body system is responsible for fighting disease and infection?
- Digestive system
- Immune system (Correct answer)
- Endocrine system
- Nervous system
Correct answer: Immune system
The immune system defends the body against pathogens such as bacteria, viruses, and other harmful invaders.
Question 5: What is photosynthesis' chemical equation?
- CO₂ + H₂O → C₆H₁₂O₆ + O₂ (with light) (Correct answer)
- O₂ + glucose → CO₂ + H₂O
- H₂O → H₂ + O₂
- CO₂ + O₂ → H₂O + energy
Correct answer: CO₂ + H₂O → C₆H₁₂O₆ + O₂ (with light)
Photosynthesis converts carbon dioxide and water into glucose and oxygen using light energy: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
Question 6: Which of the following is a characteristic shared by ALL living things?
- They all perform photosynthesis
- They all have a nucleus
- They all respond to their environment (Correct answer)
- They all are multicellular
Correct answer: They all respond to their environment
All living organisms respond to stimuli in their environment, which is one of the universal characteristics of life.
PSSA PSSA Life Science 2
What is the function of the nucleus in a cell?