Down Syndrome Congenital disease characterized by malformations of organs (heart, kidneys), moderate to severe mental retardation, thick tongue, small feet and hands, changes in features. It results from an abnormality in chromosomal constitution: affected individuals have an extra chromosome - which adds to the pair number 21 - in their cells (for this reason the disease is also called trisomy 21).
Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the transfers between trophic levels. Rather than flowing through an ecosystem, the matter that makes up living organisms is conserved and recycled. The six most common elements associated with organic molecules—carbon, nitrogen, hydrogen, oxygen, phosphorus, and sulfur—take a variety of chemical forms and may exist for long periods in the atmosphere, on land, in water, or beneath Earth’s surface.
Question 1.5. Calculating recombination frequenciesCorn kernels can be colored or white, determined by the alleles C(colored, which is dominant) or c(white, which is recessive) of the coloredgene. Likewise, alleles of the shrunkengene determine whether the kernels are nonshrunken (Sh, dominant) or shrunken (sh, recessive).