Answer:
genomic imprinting
Explanation:
Genomic imprinting is a mechanism for regulating gene expression that allows expression of only one of the parental alleles, although both alleles are functional. Unlike most genes in which expression is biallelic, genes that are subjected to this mechanism (imprinted genes) have monoalelic expression; By definition, in an imprinted loci, only one allele is active (maternal or paternal), and the inactive is epigenetically marked by histonic modification and / or methylation of cytosines.
Genomic imprinting can cause some disturbances, among them Prader-Willi syndrome, which is a genetic disorder that involves a partial deletion of chromosome 15q on the paternal chromosome.
The evolutionary effects of the genetic drift are the greatest when the population is small.
In small populations, genetic drift can significantly change the frequencies of the alleles and affect the genetic structure of the population. In big populations, the effects of the genetic drift are small and insignificant.
Ecologists are the persons who study the interrelationships between organisms and their environments. Like they research upon the species found in forests or deserts interact with each other and as well as their surroundings.
They test whether a species is occupying its complete fundamental niche or only a portion of it by observing if the species are expanding their range after the removal of a competitor because two species with the same fundamental niche will exclude other competing species.
Answer
Photosynthesis yield sugar in two main steps
1. Light reaction
In this step plant absorb sunlight which cause photolysis of water and excitation of electron. this electron flow through Z-scheme and atlast enter into NADH, the end product of light reaction is ATP and NADH₂.
2. DArk reaction.
In this step ATP and NADH₂ are used as raw materials. it occurs in stroma of chloroplast. here CO₂ is used through Calvin cycle and at the end glucose is prepared.