Answer:
The correct answer is d) genomic imprinting.
Explanation:
Genomic imprinting is a biological process by which specific modifications in the germ line that produce differences in the expression of the genetic material that is biochemically marked indicating its parental origin. The Prader-Willi syndrome is one of the best known and most studied examples in relation to pathologies produced by genomic imprinting. Prader-Willi syndrome is a complex genetic disease that is fundamentally neurological. Its appearance is due to a deletion of a fragment of chromosome 15 derived from the father.
Answer:
Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing selection
The Answer is option A (Disruptive selection)
Explanation:
Selection can either shift the mean value of a trait, reduce the trait's variation, or increase its variation.
Genetic variation which allows natural selection to increase or decrease frequency of alleles already in the population is a source of phenotypic variation as it refers to differences in all the hereditary information of members of the same species.
Disruptive Selection is important in maintaining variation and initiating speciation as it Increases Variation by favoring alleles corresponding to more extreme phenotypes. But for it to occur, the mean phenotype has to experience the lowest fitness. Disruptive selection affects the frequency distributions of alleles and genotypes within a population.
Disruptive selection is based on the variance of a trait in a population as it increases genetic variance by equalizing the frequencies of existing alleles at polymorphic loci (a genetic loci with two or more alleles). Disruptive selection maintains and may even increase variation in natural populations by favoring extreme phenotypes, individuals with extreme values for a trait have greater reproductive success than individuals with intermediate values.
Answer:
The question to be asked an investigated when observing a structure under the microscope to determine whether it is living is if it has a nucleus if eukaryote or nucleoid if prokaryote.
Explanation:
The major organelle that must be present in all living cells is the nucleus or nucleoid and the protoplasm. The observation of the cell under the microscope will show the subcellular entity, nucleus/nucleoid, more pronounced than other organelles in the cell. The nucleus house the necessary information for the maintenance and reproduction, which is mainly the genetic information that dictates the translational protein products that are needed to build another aspect of the cells. Therefore, when such a tiny structure is placed under the light microscope under the view of oil immersion, the nucleus of the cell should be visible if it is a living structure.
Cell membranes help organisms maintain homeostasis by controlling what substances may enter or leave cells
Since carotenoids stabilize dangerous free radicals, we can assume that their function is to protect the cell from the free radicals.
