A large decrease in the amount of sunlight available
A large increase in the number of carnivores
A small increase in the number of decomposers
A small decrease in the amount of minerals available
An inherited disorder
Environmental influence on gene expression
Expression of a hidden trait
A characteristic controlled by more than one pair of genes
Abnormal red blood cells
Abnormal hemoglobin molecules
A code for the production of abnormal hemoglobin
A code for the production of abnormal amino acids
Gametes with many copies of the same chromosome
Embryos with traits identical to those of all other members of the species
Zygotes with the genetic information to produce only females
Offspring with some traits that did not appear in their parents
The squirrel stops using its claws for digging.
The squirrel is exposed to radiation for several days.
Oak trees gradually become less common.
The weather becomes wetter for a short period of time.
The bacterium is able to produce a human hormone.
It allows the bacterium to grow in humans, since it contains a human gene.
It allows humans to become immune to an infection from this type of bacteria.
The bacterium can now produce human cells identical to cells of the DNA donor.
The antibiotics killed most of the bacteria that did not have a genetic variation for resistance
The bacteria needed to change in order to produce more antibiotics
Some of the bacteria learned how to resist the antibiotics
Antibiotics have become weaker over the years
Meiotic cell division
At least one sperm cell will be reached when the eggs swim toward the sperm cells in the ovary
Several sperm cells will unite with an egg so the fertilized egg will develop properly
Some of the sperm cells will survive to reach the egg
Enough sperm cells will be present to transport the egg from where it is produced to where it develops into a fetus
Their blood systems are separate only at certain times in development and connected at other times.
The blood flows directly from the mother into the fetus.
Their blood systems are separate and no materials are exchanged.
Their blood systems are separate, but certain materials pass from one to the other.
The transplanted skin is damaged, making the immune system nonfunctional.
The antigens of the replacement skin are the same as those of the damaged skin.
Burn victims lose so much blood that white blood cells cannot cause an immune response.
There is no blood supply to the skin, so mixing of antigens does not occur.
Reproductive cycles of animals
Recycling of inorganic compounds
Flow of energy
Transport of groundwater
Specialized blood cells
A variety of antibiotics
They will usually develop different requirements.
One species may adapt to a different environment.
One species may be eliminated from that ecosystem.
They will alter the environment so that they can both survive in that ecosystem.
Stored in the remains of a dead animal
Lost to the environment as heat
Stored in eggs produced during sexual reproduction
Produced in muscle tissue during the growth of an organism
Their environment has few abiotic factors
The organisms are large
The population size is small
Their species exhibits genetic variation
Humans can destroy habitats by removing flowering trees and shrubs
All animals feed directly on flowering shrubs that may be removed by people
Removal of flowering trees and shrubs will increase biodiversity
Flowering shrubs grow best in state forests and parks