animals that kill and eat other animals are-
predators
what is a biodegradable substance-
cotton rags
in undisturbed rock layers, the oldest rocks are located-
in the bottom layer.
two animals would probably show a close evolutionary relationship if they-
have a similar embryonic development.
in order to insure survival, salmon lay a large number of eggs. this is an example of-
overproduction.
a large number of active decay bacteria in lake Erie has resulted in-
a decrease of oxygen in the water.
the biologist who studied hereditary factors in pea plants was-
Mendel
in the gene pair Tt the symbol T represents a-
dominant trait.
decomposers are unable to break down-
plastic
Lamarck believed that new organisms arise in animals-
when needed
according to the theory of evolution, with the passage of time organisms have-
changed.
the gradual replacement of one species by another in a natural community is known as-
ecological succession
a ________ is a photograph of chromosomes.
a Karyotype
thermal pollution is most likely caused by-
nuclear power plants discharging heated water into a river.
a major source of air pollution is-
automobiles.
heredity traits are controlled by-
genes
the primary source of energy for life on earth is-
sunlight
the process of recycling involves the-
use and reuse of materials.
the operation of modern sewage plants help decrease-
water pollution
a structure that an animal or plant no longer used is known as a-
vestigial structure
some human inherited traits are transmitted by-
sperm cells
the species composition of a community will change over a long period of time if the-
environment changes.
the discovery of gene mutation helps to explain the-
appearance of new traits.
much of the history of human evolution is still incomplete due to the-
scarcity of human fossils
the off-spring of of two pure recessives will most likely be-
100% recessive