Specialized gland in the endocrine system release hormones that control different bodily functions.
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.
The phenotype is called Roan, a mix of white and red
I hope this helps!
In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
I think it is erosion (2) because erosion removes soil, rock, and dissolved material.
