NTN Science 1 — Questions and Answers
Question 1: What is the basic unit of life?
- Organ
- Tissue
- Cell (Correct answer)
- Molecule
Correct answer: Cell
The cell is the smallest structural and functional unit of all living organisms.
Question 2: Which of the following is a function of the human skeletal system?
- Producing hormones
- Providing structure and protecting internal organs (Correct answer)
- Filtering blood
- Absorbing nutrients
Correct answer: Providing structure and protecting internal organs
The skeletal system provides structural support, enables movement, and protects vital organs.
Question 3: Which element is essential for human red blood cells to carry oxygen?
- Calcium
- Potassium
- Iron (Correct answer)
- Sodium
Correct answer: Iron
Iron is a key component of hemoglobin, the protein in red blood cells that binds and transports oxygen.
Question 4: What process do plants use to convert sunlight into food?
- Respiration
- Fermentation
- Photosynthesis (Correct answer)
- Digestion
Correct answer: Photosynthesis
Photosynthesis is the process by which plants use sunlight, water, and CO₂ to produce glucose and oxygen.
Question 5: Which of the following correctly describes the difference between a physical change and a chemical change?
- A physical change creates a new substance; a chemical change does not
- A chemical change creates a new substance; a physical change does not (Correct answer)
- Both changes create new substances
- Neither change alters the substance
Correct answer: A chemical change creates a new substance; a physical change does not
A chemical change produces a new substance with different properties, while a physical change alters only form or appearance.
Question 6: Which body system is primarily responsible for transporting oxygen and nutrients to cells?
- Digestive system
- Nervous system
- Circulatory system (Correct answer)
- Endocrine system
Correct answer: Circulatory system
The circulatory system uses the heart, blood, and vessels to deliver oxygen and nutrients throughout the body.
NTN Science 1
What is the basic unit of life?