The fossil record of ancient life forms provides scientific evidence of
Which situation results in a characteristic that is inheritable?
A limb is lost when two marine organisms fight.
A puppy learns to beg for food by watching an older dog perform tricks.
A gene is inserted into a bacterium, allowing the organism to produce insulin.
A random mutation causes the immediate death of a microbe.
Which statement explains the importance of maintaining a constant internal environment to ensure proper enzyme functioning?
Changes in pH and temperature will cause the enzyme reaction rate to be too fast.
Temperature and pH determine amino acid sequences in enzymes.
Changes in pH will change the genetic instructions of enzymes.
Increasing the temperature and pH can alter the specific shape of enzymes.
The major function of the placenta is to
cushion the fetus so it won’t be hurt when the mother moves.
exchange food, oxygen, and waste between mother and fetus.
store food for the fetus.
support the egg for the process of fertilization.
Which statement best describes an ecosystem maintaining a state of approximate equilibrium?
Nutrients from decayed organisms are recycled in a forest ecosystem.
All the frog species in a South American rain forest become extinct.
A mutation spreads through a species of bacterium, making them unable to decompose wastes.
Mice are released into a field ecosystem as food for a declining predator population.
Which characteristic of a geographic region would have the greatest influence on the type of ecosystem that forms in that region?
ratio of autotrophs to heterotrophs
concentration of atmospheric oxygen
number of food chains
Growing exotic (nonnative) plant species in parks and gardens could lead directly to an increase in the
biodiversity of the autotrophs that feed on them.
populations of native carnivores.
competition between them and native producers.
breeding between them and native herbivores.
On hot, dry days, guard cells often close microscopic openings in plant leaves, conserving water. This is an example of
environmental factors causing gene mutation in plants
finite resources acting as selecting agents for evolution
a feedback mechanism for maintaining homeostasis
differentiation in plants as a result of stimuli
In the human body, oxygen is absorbed by the lungs and nutrients are absorbed by the small intestine. In a single-celled organism, this absorption directly involves the