Free SAT Biology Organismal Biology & Physiology Questions and Answers — Questions and Answers
Question 1: What is the function of the circulatory system?
- Digests food
- Transports substances (Correct answer)
- Controls movement
- Filters air
Correct answer: Transports substances
The circulatory system, comprising the heart, blood vessels, and blood, is responsible for transporting essential substances throughout the body. It delivers oxygen and nutrients to cells, carries hormones, and removes waste products like carbon dioxide. This vital transport network ensures all body tissues receive what they need to function.
Question 2: Which organ system controls body responses?
- Digestive system
- Respiratory system
- Nervous system (Correct answer)
- Skeletal system
Correct answer: Nervous system
The nervous system, consisting of the brain, spinal cord, and nerves, is the body's primary control and communication system. It detects stimuli, processes information, and coordinates rapid responses to both internal and external changes. This system enables thought, movement, sensation, and the regulation of vital bodily functions.
Question 3: Which structure is responsible for gas exchange in humans?
- Bronchi
- Alveoli (Correct answer)
- Trachea
- Diaphragm
Correct answer: Alveoli
Alveoli are tiny, air-filled sacs located at the end of the bronchioles in the lungs. Their extremely thin walls and large surface area facilitate the efficient exchange of oxygen from inhaled air into the bloodstream and carbon dioxide from the blood into the air to be exhaled. This critical function is essential for respiration.
Question 4: Which nutrient is the main energy source for cells?
- Protein
- Vitamin C
- Glucose (Correct answer)
- Calcium
Correct answer: Glucose
Glucose is a simple sugar that serves as the primary and most readily available energy source for most cells in the body. Through cellular respiration, glucose is broken down to produce ATP (adenosine triphosphate), the main energy currency of the cell. This process fuels all cellular activities, from muscle contraction to nerve impulses.
Question 5: Which system removes metabolic waste from the body?
- Skeletal system
- Excretory system (Correct answer)
- Muscular system
- Lymphatic system
Correct answer: Excretory system
The excretory system, primarily composed of the kidneys, bladder, ureters, and urethra, is responsible for filtering blood and removing metabolic waste products from the body. It maintains fluid and electrolyte balance, ensuring the removal of toxins like urea while retaining essential substances. This system is vital for maintaining homeostasis.
Question 6: What is the function of the skeletal system?
- Digest nutrients
- Produce hormones
- Support and movement (Correct answer)
- Control breathing
Correct answer: Support and movement
The skeletal system provides the body with structural support, forming a framework that holds the body upright and protects vital internal organs. It also works in conjunction with the muscular system to facilitate movement, as muscles attach to bones and pull on them to create motion. Additionally, bones store minerals and produce blood cells.
Question 7: Which hormone regulates blood sugar?
- Adrenaline
- Insulin (Correct answer)
- Thyroxine
- Estrogen
Correct answer: Insulin
Insulin is a vital hormone produced by the pancreas that plays a central role in regulating blood glucose (sugar) levels. After a meal, when blood sugar rises, insulin signals cells to absorb glucose from the bloodstream for energy or storage. This action effectively lowers blood sugar, maintaining the body's internal balance.
Question 8: Where does digestion begin in the human body?
- Stomach
- Small intestine
- Mouth (Correct answer)
- Esophagus
Correct answer: Mouth
Digestion in the human body commences in the mouth, where both mechanical and chemical processes begin. Chewing mechanically breaks down food into smaller, more manageable pieces, while salivary amylase, an enzyme in saliva, starts the chemical breakdown of carbohydrates. This initial processing prepares food for further digestion in the stomach and small intestine.
Question 9: What is homeostasis?
- Growth of an organism
- Maintaining internal balance (Correct answer)
- Digesting food
- Producing offspring
Correct answer: Maintaining internal balance
Homeostasis is the crucial biological process by which living organisms maintain a stable internal environment despite external fluctuations. This involves a range of physiological mechanisms that regulate factors such as body temperature, pH, blood glucose, and water balance. Maintaining this internal equilibrium is essential for an organism's survival and optimal functioning.
Free SAT Biology Organismal Biology & Physiology Questions and Answers
What is the function of the circulatory system?