TEAS 7 Chemistry: Essential Practice for Success

ATI TEAS 7

Chemistry

1. What do isotopes of the same element have in common?

A. Identical number of protons and neutrons.
B. Identical chemical properties.
C. Identical number of electrons.
D. Identical mass number.

Correct answer: A

Rationale: Identical number of protons and neutrons - Isotopes have the same atomic number but different mass numbers due to varying neutron counts.

2. How many bones are there in the adult human skeleton?

A. 126
B. 206
C. 300
D. 525

Correct answer: D

Rationale: The correct answer is D: 525. The adult human skeleton consists of 206 bones. However, when accounting for individual bones, many of them are paired (like the ribs and vertebrae), bringing the total count to 206 individual bones but 525 in total when considering pairs. This includes bones in the skull, spine, ribs, arms, hands, pelvis, legs, and feet. So, while there are 206 individual bones, the total number of bones in the adult human skeleton is 525 when considering pairs.

3. The main function of the nephrons is to:

A. Store urine
B. Filter blood and remove waste products
C. Produce hormones
D. Control blood pressure

Correct answer: B

Rationale: The correct answer is B: 'Filter blood and remove waste products.' Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water, while reabsorbing essential substances like glucose and amino acids. This process forms urine, which is stored in the bladder before being excreted. Options A, C, and D are incorrect because nephrons do not store urine, produce hormones, or directly control blood pressure; although the kidneys do play a role in long-term blood pressure regulation through mechanisms like the renin-angiotensin-aldosterone system.

4. What is the difference between isometric and isotonic muscle contractions?

A. Isometric involves movement, while isotonic does not.
B. Isotonic involves shortening of muscle, while isometric maintains length.
C. Isometric uses more energy, while isotonic uses less.
D. Isotonic involves smooth muscle, while isometric involves skeletal muscle.

Correct answer: B

Rationale: The correct answer is B: "Isotonic involves shortening of muscle, while isometric maintains length." Isometric contractions occur when the muscle generates force without changing its length, such as holding a weight in a fixed position. On the other hand, isotonic contractions involve the muscle changing length, either by shortening (concentric contraction) or lengthening (eccentric contraction) while generating force. Understanding this distinction is crucial for grasping the different types of muscle contractions and their effects on the body during exercise and movement.

5. The urethra is the tube that carries urine from the bladder to the outside of the body. How does urine flow through the urethra?

A. Continuously
B. Only when the bladder is completely full
C. Under voluntary control of sphincter muscles
D. A combination of b) and c)

Correct answer: C

Rationale: The correct answer is C: "Under voluntary control of sphincter muscles." The urethra is the tube responsible for carrying urine from the bladder to the outside of the body. Urine flow through the urethra is not continuous but rather under voluntary control. The sphincter muscles, located at the opening of the bladder and urethra, help control the release of urine. This control allows individuals to regulate when and where they empty their bladder, providing a mechanism to prevent involuntary leakage of urine. Therefore, option C accurately describes how urine flows through the urethra.