Answer:
Lichens are not parasitic when they grow on trees, they just use the tree bark as a home. They enrich the soil by trapping water, dust and silt. When lichens die they contribute organic matter to the soil, improving the soil so that other plants can grow there.
Natural selection is the process in which the more favorable traits due to mutation that are in a select few in a population produce more offspring then others. An example of this is bacteria resistant to antibiotics due to the faster reproduction of the resistant bacteria over the non resistant ones
Answer:
The options
a. New combinations of genes yielding genotypes of greater fitness
b. Few heterozygotes because of underdominance
c. Frequency-dependent selection, leading to fluctuations in fitness
d. Heterozygotes with greater fitness, owing to overdominance
e. A random assortment of genotypes because of genetic drift
The CORRECT ANSWER IS b.
b. Few heterozygotes because of under dominance
Explanation:
In genetics, underdominance (at times called "negative overdominance") is the opposite of overdominance.
It is the selection against the heterozygote, that leads to disruptive selection and divergent genotypes. It occurs in cases of inferior and reduced fitness (As in our case study, it is the different chromosomal fusions and inversions)
of the heterozygotic genotype to the dominant or recessive homozygotic genotype. It is unstable as it causes fixation of either allele.
Another example is the African butterfly species Pseudacraea eurytus, which makes use of Batesian mimicry to avoid predation. This species carries two alleles that gives a coloration that is alike to a different local butterfly species that is harmful to its predator. The butterflies who are heterozygous for this trait are observed to be intermediate in coloration and thus encounter an higher risk of predation and a decrease in the total fitness.
Biomolecules are organic compounds that are present as essential components of living things. There are four major biomolecules namely lipids, proteins, carbohydrates and nucleic acids. Proteins, lipids and glucose are usually used by organisms as energy sources as well as structural components among other functions in living organisms. Nucleic acids are important components that bring about heredity. In this case the appropriate molecule to be chosen by the long distance learner would be carbohydrate because it stores and may be used as a source of energy.
