ASVAB ASVAB Certifications ASVAB-SECTION-7 Questions & Answers

• Question 81:

  In vertebrates, which substance gives red blood cells their color?

  A. carotene

  B. dopamine

  C. melanin

  D. hemoglobin

  Correct Answer: D

  Explanation:

  Hemoglobin, used by all vertebrates and some invertebrates to transport oxygen and carbon dioxide in the

  body, gives red blood cells their color.

• Question 82:

  Via which of the following unoxygenated blood travels to the heart?

  A. arteries

  B. veins

  C. capillaries

  D. aorta

  Correct Answer: B

  Explanation:

  Veins carry blood devoid of oxygen to the right atrium of the heart.

  Arteries, capillaries, and the aorta carry oxygenated blood from the heart to blood cells throughout the

  body.

• Question 83:

  Which of the following ecosystems could be described as housing thousands of species and has tall trees that form a ceiling from the the Sun above?

  A. a deciduous forest

  B. a tropical rain forest

  C. a tundra

  D. a taiga

  Correct Answer: B

  Explanation:

  Tropical rain forests are one of the most important areas on Earth.

  These special ecosystems are home to thousands of species animals and plants. Rain forests are not only

  densely packed with plants, but are also full of tall trees that form a ceiling from the Sun above. This ceiling

  keeps smaller plants from growing. Areas where sunlight can reach the surface are full of interesting

  plants.

• Question 84:

  __________ is the reason it is harder to stop a baseball flying at 100 MPH than it is to stop a baseball flying at 50 MPH.

  A. Velocity

  B. Momentum

  C. Mass

  D. Volume

  Correct Answer: B

  Explanation:

  Momentum equals mass (amount of matter in an object) times velocity (speed in a given direction).

• Question 85:

  What is the scientific notation for 832,000?

  A. 8.32 × 10-2

  B. 8.32 × 102

  C. 8.32 × 10-5

  D. 8.32 × 105

  Correct Answer: D

  Explanation:

  To express a number in scientific notation, you move the decimal as many places as necessary until there

  is only one digit to the left of the decimal.

  For 832,000, you move the decimal to the left by 5 decimal places.

• Question 86:

  The particle with a __________ charge in the nucleus of an atom is a(n) __________.

  A. positive, electron

  B. positive, proton

  C. negative, neutron

  D. neutral, positron

  Correct Answer: B

  Explanation:

  The particle with a positive charge in the nucleus of an atom is a proton.

  The nucleus of an atom contains protons, (which have a positive electrical charge) and neutrons, (which

  have no electrical charge).

  Electrons, which have a negative charge, circle the nucleus in what is known as the orbital shell.

• Question 87:

  Electrons have a __________ charge.

  A. positive

  B. negative

  C. neutral

  D. variable

  Correct Answer: B

  Explanation:

  Electrons have a negative charge.

• Question 88:

  The four forces that act on an aircraft in flight are __________.

  A. lift, thrust, friction, and inertia

  B. lift, gravity, thrust, and drag

  C. thrust, vector, speed, and fluid density

  D. lift, downdraft, thrust, and vector

  Correct Answer: B

  Explanation:

  The four forces that act on an aircraft in flight are lift, gravity, thrust, and drag.

• Question 89:

  A lens surface that is __________ bulges outward from the lens, while a lens surface that is __________ is depressed into the lens.

  A. planar, convex

  B. concave, convex

  C. convex, concave

  D. orthogonal, planar

  Correct Answer: C

  Explanation:

  A lens surface that is convex bulges outward from the lens, while a lens surface that is concave is

  depressed into the lens.

• Question 90:

  Antibodies __________.

  A. identify and neutralize foreign objects inside the body.

  B. bond with antigens to keep the body's hormones balanced.

  C. prevent infection by blocking access to the circulatory system.

  D. are produced by the endocrine system.

  Correct Answer: A

  Explanation: Antibodies identify and neutralize foreign objects inside the body. Humans and other vertebrates have an immune system that uses antibodies to fight bacteria, viruses, toxins, and other foreign objects. Antibodies are complex, Y-shaped protein molecules that develop from plasma cells, which in turn develop from "B lymphocytes" produced by the bone marrow. The plasma cells can generate a very large array of different antibodies, each of which can combine with and destroy an antigen (foreign molecule). Antibodies react to very specific characteristics of different antigens, binding them to the top ends of their Y-shaped form. Once the antibody and antigen combine, the antibodies deactivate the antigen or lead it to macrophages (a type of white blood cell) that ingest and destroy it. High counts of a particular antibody may persist for months after an invasion before eventually diminishing. However, the B cells can quickly manufacture more of the same antibody if exposure to that particular antigen reoccurs. Vaccines work by "training" B cells to recognize and react quickly to potential disease molecules.