What is the name of the dome-shaped muscle that plays a key role in breathing?
A. Diaphragm
B. Trachea
C. Bronchus
D. Alveoli
The diaphragm is a dome-shaped muscle that plays a key role in breathing. It separates the thoracic cavity, which contains the heart and lungs, from the abdominal cavity. When the diaphragm contracts, it moves downward and increases the volume of the thoracic cavity, allowing air to flow into the lungs. When it relaxes, it moves upward and decreases the volume of the thoracic cavity, forcing air out of the lungs.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What is the largest organ in the human body by surface area?
A. Brain
B. Heart
C. Liver
D. Skin
Answer Explanation
The largest organ in the human body by surface area is the skin. It covers the enre external surface of the body and has an average surface area of about 20 square feet in adults.
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Q #2: What is the difference between isotonic and isometric muscle contractions?
A. Isotonic contractions produce no movement while isometric contractions produce movement.
B. Isotonic contractions produce movement while isometric contractions produce no movement.
C. Isotonic contractions generate tension in the muscle while isometric contractions involve shortening of the muscle fibers.
D. Isotonic contractions involve contraction of individual muscle fibers while isometric contractions involve the entire muscle.
Answer Explanation
Isotonic and isometric contractions are two types of muscle contractions that differ in the amount of force produced and the movement of the muscle. In isotonic contractions, the muscle changes length and produces movement, such as lifting a weight. The force generated by the muscle remains constant throughout the movement. Isotonic contractions can be further classified as concentric contractions, in which the muscle shortens as it contracts, and eccentric contractions, in which the muscle lengthens as it contracts.
In contrast, isometric contractions occur when the muscle generates force without changing its length or producing movement. For example, holding a weight in a fixed position without moving it requires an isometric contraction. In an isometric contraction, the force generated by the muscle increases up to a maximum and then remains constant. Isometric contractions can be used to build strength and endurance in the muscle, but they do not produce movement.
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Q #3: What is the function of ribosomes in a cell?
A. To produce energy for the cell
B. To store genetic information
C. To transport molecules within the cell
D. To synthesize proteins in the cell
Answer Explanation
Ribosomes are small, spherical structures found in all living cells, including bacteria, archaea, and eukaryotes. Their primary function is to synthesize proteins using the genetic information stored in the cell's DNA. Ribosomes are composed of two subunits, one large and one small, that come together during protein synthesis.
Ribosomes read the genetic information stored in mRNA (messenger RNA) and use this information to assemble amino acids in the correct order to form a protein. The ribosome moves along the mRNA, adding one amino acid at a time to the growing protein chain until it reaches the end of the mRNA and the protein is complete.
Proteins are essential for a wide variety of cellular functions, including catalyzing chemical reactions, providing structural support, and transporting molecules across cell membranes. Therefore, ribosomes play a critical role in the overall function and survival of a cell.
