Answer:
When a single amino acid is encoded by more than one codon.
Explanation:
Degeneracy is when a single amino acid is encoded by more than one codon. This pehonomenon was first described by Lagerkvist where there are more codons than amino acids that could be encoded.
Answer:
Competition for resources like food and space cause the growth rate to stop increasing, so the population levels off. ... The carrying capacity (K) is the maximum population size that can be supported in a particular area without destroying the habitat. Limiting factors determine the carrying capacity of a population. Population Growth Limits | CK-12 Foundation
A confounding variable refers to an external effect, which modifies the influence of an independent and dependent variable. This extraneous effect is used to affect the outcome of an experimental design. The confounding variables can ruin the experiment and can generate unnecessary outcomes.
In the given case, confounding variables can be introduced by testing multiple hypotheses at a time and by using distinct kinds of soil in each of the samples.