Answer:
Multiple alleles can modify the classical Mendelian ratio by increasing the number of phenotypes.
For example, in a monohybrid cross, Mendel gets only 2 phenotypes however, in ABO blood groups (a classical example of multiple alleles) there are four phenotypes present in a population.
Lethal alleles are the alleles which when expressed result in the death of an organism. These alleles can be dominant, recessive or conditional (depends on interaction with another gene).
Thus, lethal allele reduces the ratio of the phenotype associated with it by affecting the survival of the organism.
For example, lethal yellow allele in mice results changes the phenotype ratio from 3:1 to 2:1
<span>When looking to power your equipment or vehicle with natural gas. A lot of people use natural gas in their homes for cooking and heating, but they don’t really give it some thought. So, let’s see what natural gas is and how it’s different from other </span>forms of fossil fuels<span> like oil and coal.</span>
Mussels are molluscans and are freshwater animals. The change in the environment led to new traits of mussels, it underwent natural selection and the thick shells have high chances of survival.
<h3>What is natural selection?</h3>
Natural selection is a process of nature that eliminates the organism with less survival and unfit traits while selecting the organisms with better traits of survival in the altered conditions.
The arrival or the introduction of the crabs in the environment altered the previous habitat of the mussels and led to the adaptation of the better trait quality in the mussel species.
The trait of the thick shells underwent natural selection as they were favoured for the changed conditions. The mussel having thick shells have high chances of survival over thin-shelled mussels as the crab will find it hard to attack the thick-shelled mussels.
Therefore, option A. change in environment, option B. natural selection and option E. chances of survival are the correct statements.
Learn more about the natural selection here:
brainly.com/question/10715606
Answer:
Biotic factors such as the presence of autotrophs or self-nourishing organisms such as plants, and the diversity of consumers also affect an entire ecosystem. Abiotic factors affect the ability of organisms to survive and reproduce. Abiotic limiting factors restrict the growth of populations.
Explanation:
