1.
About 98% of the human body is composed of only six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorous.
Correct Answer
A. True
Explanation
The given statement is true. It states that about 98% of the human body is composed of only six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorous. This means that these six elements make up a significant majority of the human body's composition.
2.
The respiratory system is responsible for:
Correct Answer
E. A, B, and C
Explanation
The respiratory system is responsible for supplying oxygen to the body, eliminating carbon dioxide in the body, and regulating the body's pH balance. Oxygen is needed by the body's cells for energy production, and carbon dioxide is a waste product that needs to be removed. The respiratory system also plays a role in maintaining the body's acid-base balance, helping to regulate the pH levels in the blood. Therefore, the correct answer is A, B, and C.
3.
Excretion is one function of the digestive system.
Correct Answer
A. True
Explanation
Excretion is indeed one function of the digestive system. While the primary role of the digestive system is to break down and absorb nutrients from food, it also eliminates waste products from the body through excretion. The digestive system removes indigestible materials and waste products, such as undigested food, toxins, and metabolic byproducts, through the process of defecation. This helps maintain the overall health and balance of the body by getting rid of substances that are no longer needed or harmful.
4.
The main purpose of hormones is to:
Correct Answer
D. All of the above
Explanation
Hormones play a crucial role in regulating various processes in the body. They can alter the rate of synthesis of cellular proteins, which is important for growth and development. Additionally, hormones can change the rate of enzyme activity, which affects the overall metabolic processes in the body. They also have the ability to change the rate of transport of nutrients through the cell wall, ensuring that cells receive the necessary nutrients for their proper functioning. Therefore, the correct answer is "All of the above."
5.
The nervous system is made up of the:
Correct Answer
D. A and B
Explanation
The correct answer is A and B, which means the nervous system is made up of both the peripheral nervous system and the central nervous system. The peripheral nervous system includes all the nerves and ganglia outside of the brain and spinal cord, while the central nervous system consists of the brain and spinal cord. Both systems work together to coordinate and regulate the body's functions and responses to stimuli.
6.
The circulatory system consists of:
Correct Answer
C. Heart, arteries, and veins
Explanation
The circulatory system consists of the heart, arteries, and veins. These are the main components responsible for the transportation of blood throughout the body. The heart acts as a pump, pushing oxygenated blood to the arteries, which carry it to different parts of the body. Veins then return the deoxygenated blood back to the heart. The lungs, mouth, throat, trachea, and bronchi are part of the respiratory system, while the mouth, esophagus, stomach, and gallbladder are part of the digestive system. Therefore, the correct answer is heart, arteries, and veins.
7.
Hemoglobin is an oxygen transporting protein in red blood cells.
Correct Answer
A. True
Explanation
Hemoglobin is indeed an oxygen transporting protein in red blood cells. It binds to oxygen in the lungs and carries it throughout the body, delivering it to tissues and organs. This process is essential for the proper functioning of cells and maintaining overall health. Therefore, the statement "Hemoglobin is an oxygen transporting protein in red blood cells" is true.
8.
Hormones are classified as:
Correct Answer
D. All of the above
Explanation
Hormones can be classified into three main categories: steroids, amino acid derivatives, and peptides. Steroids are derived from cholesterol and include hormones such as cortisol and testosterone. Amino acid derivatives are derived from amino acids and include hormones such as epinephrine and thyroid hormones. Peptides are made up of chains of amino acids and include hormones such as insulin and growth hormone. Therefore, all of the options mentioned (steroids, amino acid derivatives, and peptides) are correct classifications for hormones.