Answer:
Epigenetic phenomena
Explanation:
Epigenetics involves the changes in gene expression which is not as a result of changes in an individual's DNA sequence. In other words, it is a change in an individual's phenotype, without an alteration in the genotype.
It is involved in the normal functioning of cellular processes.
Examples of epigenetics is DNA methylation ( adding of a methyl group to a section of the DNA molecule) and histone modification such as histone acetylation (adding an acetyl group to the histone).
Epigenetic changes can switch off genes, hence, prevent the expression of those genes; it can also turn on genes, hence increase the expression of those genes.
Epigenetic changes can also results to diseases such as cancer.
C. grow and develop, because the picture shows how a seedling grows into a tree until that tree spreads its own seeds, and the cycle continues.
The genetic base of the shape of orchid is very complex.
Mendelian traits are described as simple traits determined by one gene. The different alleles of the gene contribute to the difference in the trait. This is true for some traits in plants, animals including humans and other organisms, but not for the shape of orchids.
The shape of orchid flowers is determined by the ABCDE group of genes that are responsible for the body plan in plants. These genes are the equivalent of HOX genes of animals.
The protein products of different genes of the ABCDE group interact with each other in complex ways creating different shapes of orchids.
