Which statement describes an effect of natural
selection on a species?
(1) it favors the survival of certain members
of the species and results in a change in
the proportion of individuals with highly
adaptive traits.
(2) it provides feedback mechanisms for members
of a species and results in a change in the
proportion of individuals with homeostatic
controls.
(3) it leads to reproduction with other species,
increasing the number of different adaptations.
(4) it increases competition between populations
that occupy different niches, increasing the
chance of extinction of the less-adapted
species.

All living organisms are composed of a. only one cell. b. at least 100 cells. c. at least three cells. d. one or more cells.

(drag each tile to the correct identify which questions can be answered by what can be answered by science or which cannot. -is it right or wrong to use genetic engineering to produce new food products? -what are the most common social settings that tend to produce accomplished artists? -if a new gene is added to the genome of a tomato species, will that species be more resistant to insects? -should humans use biotechnology to bring extinct organisms from the fossil record back to life? -do the types of organisms found in the fossil record appear in consistent sequences in different parts of the world? -are michelangelo's paintings more impressive than rembrandt's?

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.