Explanation:
Pangea
Pangea is the belief that all continents were all connected at one time
Answer:
b)a gray cat is the offspring of a black cat and a white cat.
Explanation:
We can eliminate a because sperm is used in sexual reproduction, c is an example of a cat inheriting a trait from it's parents which would be sexual reproduction, and d is 2 plants mating which is also sexual reproduction which only leaves you with b)a gray cat is the offspring of a black cat and a white cat.
Answer:
If the petri plates are kept open for the longer duration of time then there are chances of cross contamination.
The contamination can be defined as growth of undesired microbes in the petri dishes or tubes which is no longer useful for the experiment.
The tube if kept open will develop the growth of contaminants in it. It can be cross contamination as well.
To avoid contamination the tubes and dishes should not be kept open for a longer duration of time.
Used for energy by mammals