The Human Body

What is the basic unit of life?

• Atom

• Cell

• Tissue

• Organ

Answer explanation

The basic unit of life is the cell. Cells are the smallest structural and functional units in living organisms, making them fundamental to all biological processes.

Which of the following is NOT a type of tissue?

• Epithelial

• Connective

• Muscular

• Nervous

• All of the above are types of tissue

Answer explanation

Epithelial, connective, muscular, and nervous are all recognized types of tissue in the body. Therefore, the correct answer is 'All of the above are types of tissue', as none of the options listed are incorrect.

What is the highest level of organization in the human body?

• Cell

• Tissue

• Organ

• Organ system

Answer explanation

The highest level of organization in the human body is the organ system. Organ systems consist of groups of organs that work together to perform complex functions, making them the most comprehensive level of biological organization.

Which organ system is responsible for breaking down food?

• Respiratory system

• Digestive system

• Circulatory system

• Nervous system

Answer explanation

The digestive system is responsible for breaking down food into nutrients that the body can absorb. It includes organs like the stomach and intestines, which process food, unlike the respiratory, circulatory, and nervous systems.

Which organ system is responsible for removing waste from the body?

• Respiratory system

• Digestive system

• Excretory system

• Nervous system

Answer explanation

The excretory system is responsible for removing waste from the body, including excess water, salts, and metabolic waste. The respiratory system removes carbon dioxide, the digestive system processes food, and the nervous system controls body functions.

The smallest unit of matter is called an ________.

Answer explanation

The smallest unit of matter is called an atom. Atoms are the basic building blocks of all substances, consisting of protons, neutrons, and electrons.

Two or more atoms bonded together form a ________.

Answer explanation

Two or more atoms bonded together form a molecule. This is the basic definition of a molecule in chemistry, highlighting the importance of atomic bonding.

A group of similar cells working together is called a ________.

Answer explanation

A group of similar cells working together is called a tissue. Tissues perform specific functions in the body, making them essential for the overall operation of organs and systems.

The heart and blood vessels are part of the ________ system.

Answer explanation

The heart and blood vessels work together to circulate blood throughout the body, making them key components of the circulatory system.

The ________ system is responsible for sending messages throughout the body.

Answer explanation

The nervous system is responsible for transmitting signals and messages throughout the body, coordinating actions and responses. It includes the brain, spinal cord, and nerves, making it the correct choice for this question.