General Science Flashcards
The DNA of a cell is found mainly in its
a) membrane
b) cytoplasm
c) chromosomes
d) vacuoles
e) mitochondria
c) chromosomes
are composed of DNA and protein and are usually found in the nucleus
Which substance can be used to treat drinking water of questionable purity?
a) ammonia
b) iodine
c) chlorine
d) hydrogen chloride
e) ethylene glycol
b) Iodine
crystals in a small bottle of water make a saturated aqueous solution; a few milliliters of this solution added to a quart of water will destroy most organisms in an hour.
The end product(s) of protein digestion consist(s) of
a) glucose
b) fatty acids
c) amino acids
d) glycerol
e) sucrose
c) amino acids
Proteins are synthesized from a variety of amino acid building blocks. Digestion breaks down these complex protein structures.
The kinetic energy of a 1-kg mass, dropped from a height of 1 meter, just before it hits the ground is
a) 1 Joule
b) 10 Joule
c) 100 Joule
d) 1, 000 Joule
e) 10, 000 Joule
b) 10 Joule
In this example the gravitational potential energy is converted into kinetic energy. The kinetic energy is equal to the mass of the object, m, multiplied by the acceleration caused by the force of gravity, g, multiplied by the distance of height involved, h,
Thus,
mgh = 1kg*9.8m/sec^2 * 1m =9.8J ~10J
A 120-V electrical power supply produces 1/2 A to the load. The power delivered is
a) 60 watts
b) 60 ohms
c) 120 watts
d) 240 watts
e) 240 ohms
a) 60 watts
P=IV
P=120V*1/2A=60 W
Most cells without a cell wall would also lack
a) vacuoles
b) chloroplasts
c) mitochondria
d) a cell membrane
e) a nucleus
b) chloroplasts
The cell wall, composed mainly of cellulose, is an important characteristic of plant cells. Chloroplasts contain energy-accumulating pigments and are found only in plant cells. Cells without cell walls would not be plant cells and would therefore not have chloroplasts, either.
The glucose content of the blood is regulated by
a) ACTH
b) nerve simulations
c) corticosteroids
d) insulin and adrenaline
e) progesterone
d) insulin and adrenaline
The relative concentration of glucose is maintained by the combined action of insulin from the pancreas and adrenaline from the adrenal medulla.
A magnifying glass is what kind of lens used on the objects how far away?
a) convex lens used beyond one focal length
b) convex lens used closer than one focal length
c) concave lens used beyond one focal length
d) concave lens used closer than one focal length
e) none of the above
d) A magnifying glass is a concave lens used for objects closer than one focal length. The object held closer than one focal length from a convex lens will produce a virtual magnified image.
