CSLB General Building (B) — All Questions

Which organ system is primarily responsible for transporting oxygen and nutrients throughout the body?

• a.Digestive system
• b.Circulatory system✓
• c.Skeletal system
• d.Integumentary system

The circulatory (cardiovascular) system uses the heart, blood, and vessels to transport oxygen, nutrients, and waste throughout the body. The digestive system breaks down food, and the skeletal system provides structure.

What is the basic structural and functional unit of all living organisms?

• a.The cell✓
• b.The atom
• c.The organ
• d.The tissue

The cell is the smallest unit that can carry out all life processes and is the fundamental building block of all living organisms. Atoms are units of matter, while tissues and organs are groups of cells.

Which part of the cell is responsible for producing energy in the form of ATP?

• a.Nucleus
• b.Ribosome
• c.Mitochondria✓
• d.Cell membrane

The mitochondria are the powerhouse of the cell, generating ATP through cellular respiration. The nucleus stores DNA, and ribosomes synthesize proteins.

During inhalation, the diaphragm contracts and moves in which direction?

• a.Upward
• b.Sideways
• c.It does not move
• d.Downward✓

When the diaphragm contracts, it flattens and moves downward, increasing the volume of the chest cavity and drawing air into the lungs. During exhalation it relaxes and moves upward.

Which type of blood vessel carries blood away from the heart?

• a.Veins
• b.Arteries✓
• c.Capillaries
• d.Venules

Arteries carry blood away from the heart to the body's tissues. Veins return blood to the heart, and capillaries are the tiny vessels where exchange of gases and nutrients occurs.

What is the pH value that is considered neutral on the pH scale?

• a.7✓
• b.0
• c.14
• d.10

The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 are acidic and values above 7 are basic (alkaline). Pure water has a pH of 7.

Which macromolecule serves as the primary source of quick energy for the body?

• a.Proteins
• b.Lipids
• c.Carbohydrates✓
• d.Nucleic acids

Carbohydrates are broken down into glucose, the body's main and most readily available source of energy. Proteins build tissue and lipids store energy long-term.

In the scientific method, what is a hypothesis?

• a.A proven fact
• b.A final conclusion
• c.A measurement tool
• d.A testable prediction✓

A hypothesis is a testable, tentative explanation or prediction that can be supported or refuted through experimentation. It is proposed before data collection, not a proven fact or conclusion.

Which organ is the primary site of nutrient absorption in the digestive system?

• a.Stomach
• b.Small intestine✓
• c.Large intestine
• d.Esophagus

The small intestine, with its finger-like villi, is where most nutrient absorption occurs. The stomach mainly digests food, and the large intestine absorbs water and forms waste.

How many chromosomes are found in a typical human body (somatic) cell?

• a.46✓
• b.23
• c.44
• d.48

A typical human somatic cell contains 46 chromosomes, arranged in 23 pairs. Gametes (egg and sperm) contain 23 chromosomes each.

Which of the following is an example of a chemical change?

• a.Melting ice
• b.Cutting paper
• c.Rusting iron✓
• d.Boiling water

Rusting iron forms a new substance (iron oxide), making it a chemical change. Melting, cutting, and boiling are physical changes that do not alter chemical composition.

The central nervous system consists of which two structures?

• a.Heart and lungs
• b.Nerves and muscles
• c.Arteries and veins
• d.Brain and spinal cord✓

The central nervous system is composed of the brain and spinal cord, which process and coordinate information. The peripheral nervous system consists of the nerves outside these structures.

What is the process by which plants convert sunlight into chemical energy?

• a.Respiration
• b.Photosynthesis✓
• c.Digestion
• d.Fermentation

Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to produce glucose and oxygen. Respiration is the reverse process that releases energy from glucose.

Which subatomic particle carries a negative electrical charge?

• a.Electron✓
• b.Proton
• c.Neutron
• d.Nucleus

Electrons carry a negative charge and orbit the nucleus. Protons carry a positive charge, and neutrons have no charge; both protons and neutrons reside in the nucleus.

Which system includes the bones and provides support and protection for the body?

• a.Muscular system
• b.Nervous system
• c.Skeletal system✓
• d.Endocrine system

The skeletal system is made up of bones that provide structural support and protect internal organs. It also works with muscles to allow movement.

What is the main function of red blood cells?

• a.Fight infection
• b.Form blood clots
• c.Produce antibodies
• d.Carry oxygen✓

Red blood cells contain hemoglobin, which binds and transports oxygen from the lungs to the body's tissues. White blood cells fight infection and platelets help form clots.

In a controlled experiment, the variable that is deliberately changed by the researcher is called the:

• a.Dependent variable
• b.Independent variable✓
• c.Control group
• d.Constant

The independent variable is the factor the researcher intentionally manipulates to observe its effect. The dependent variable is what is measured in response.

Which gas do humans primarily exhale as a waste product of cellular respiration?

• a.Carbon dioxide✓
• b.Oxygen
• c.Nitrogen
• d.Hydrogen

Cellular respiration produces carbon dioxide as a waste product, which humans exhale. Oxygen is inhaled and used to help release energy from glucose.

Which of the following best describes the role of enzymes in the body?

• a.They store genetic information
• b.They transport oxygen
• c.They speed up chemical reactions✓
• d.They provide structural support

Enzymes are biological catalysts that lower activation energy and speed up chemical reactions without being consumed. They do not store genetics or carry oxygen.

The kidneys are the primary organs of which body system?

• a.Respiratory system
• b.Digestive system
• c.Nervous system
• d.Urinary system✓

The kidneys are the main organs of the urinary (renal) system, filtering blood to remove waste and excess water, forming urine. They also help regulate blood pressure and electrolytes.

An atom that has gained or lost electrons and therefore carries a charge is called a(n):

• a.Isotope
• b.Ion✓
• c.Molecule
• d.Compound

An ion is an atom or group of atoms with a net electrical charge due to gaining or losing electrons. Isotopes differ in neutron number, not charge.

Which chamber of the heart pumps oxygenated blood to the entire body?

• a.Left ventricle✓
• b.Right ventricle
• c.Left atrium
• d.Right atrium

The left ventricle is the heart's strongest chamber and pumps oxygenated blood through the aorta to the whole body. The right ventricle pumps blood to the lungs.

Which of the following correctly orders levels of biological organization from smallest to largest?

• a.Organ, tissue, cell, organism
• b.Tissue, cell, organ, organism
• c.Cell, tissue, organ, organism✓
• d.Organism, organ, tissue, cell

The correct order from smallest to largest is cell, tissue, organ, organism. Cells form tissues, tissues form organs, and organs form the whole organism.

Which of the following is a function of the liver?

• a.Producing insulin
• b.Filtering air
• c.Pumping blood
• d.Detoxifying harmful substances✓

The liver detoxifies harmful substances, produces bile, and stores nutrients. Insulin is produced by the pancreas, and the heart pumps blood.

In genetics, an allele that is expressed only when two copies are present is called:

• a.Dominant
• b.Recessive✓
• c.Codominant
• d.Mutant

A recessive allele is expressed only when an individual has two copies of it. A dominant allele is expressed even when only one copy is present.

What is the primary purpose of a control group in an experiment?

• a.To provide a baseline for comparison✓
• b.To change the independent variable
• c.To guarantee the hypothesis is correct
• d.To measure only the dependent variable

A control group does not receive the experimental treatment and serves as a baseline for comparison. Comparing the experimental group to it helps isolate the effect of the independent variable.

Which part of the neuron receives signals from other neurons?

• a.Axon
• b.Myelin sheath
• c.Dendrites✓
• d.Synapse

Dendrites are branch-like extensions that receive incoming signals from other neurons. The axon carries signals away from the cell body toward other cells.

Which of the following bonds involves the sharing of electrons between atoms?

• a.Ionic bond
• b.Hydrogen bond
• c.Metallic bond
• d.Covalent bond✓

A covalent bond forms when atoms share electrons. An ionic bond involves the transfer of electrons, resulting in oppositely charged ions that attract.

The hormone insulin, which lowers blood glucose levels, is produced by the:

• a.Liver
• b.Pancreas✓
• c.Thyroid
• d.Adrenal glands

Insulin is produced by beta cells in the pancreas and helps lower blood glucose by promoting its uptake into cells. The thyroid regulates metabolism.

Which process describes the movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration?

• a.Osmosis✓
• b.Active transport
• c.Filtration
• d.Combustion

Osmosis is the passive diffusion of water across a semipermeable membrane from low to high solute concentration until equilibrium is reached. It requires no energy input.

Which type of muscle tissue is found in the walls of the heart and contracts involuntarily?

• a.Skeletal muscle
• b.Smooth muscle
• c.Cardiac muscle✓
• d.Voluntary muscle

Cardiac muscle is found only in the heart and contracts involuntarily and rhythmically. Skeletal muscle is voluntary, and smooth muscle lines internal organs.

What is the correct unit for measuring the amount of matter (mass) in an object?

• a.Liter
• b.Meter
• c.Newton
• d.Gram✓

Mass, the amount of matter in an object, is measured in grams (or kilograms). Liters measure volume, meters measure length, and newtons measure force.

Which body system works with the nervous system to maintain homeostasis by releasing hormones?

• a.Skeletal system
• b.Endocrine system✓
• c.Muscular system
• d.Lymphatic system

The endocrine system releases hormones into the bloodstream to regulate processes such as growth and metabolism. It works alongside the nervous system to maintain homeostasis.

If a student measures the boiling point of pure water at sea level, the expected temperature is approximately:

• a.100 degrees Celsius✓
• b.0 degrees Celsius
• c.50 degrees Celsius
• d.37 degrees Celsius

Pure water boils at 100 degrees Celsius (212 degrees Fahrenheit) at sea level. Zero degrees Celsius is the freezing point, and 37 degrees Celsius is normal body temperature.