Cellulose is another long polymer of glucose. Plant cells make their cell walls out of cellulose. In fact, 100 billion tons of cellulose is made every year on earth. Cellulose is indigestible in most animals, including us. Ever eat a cardboard box? You get the picture. We simply lack cellulase, the enzyme that can break it down. Some bacteria, some single-celled protists, and fungi have the enzyme. Animals that feed on cellulose harbor these microbes that help them digest it. Even though, we cannot break down this molecule, we do need cellulose in our diet. We call it “fiber”. Cellulose stimulates the colon to produce regular bowel movements and helps make the stools large and soft. A diet rich in fiber can prevent a painful intestinal disorder called diverticulosis. Hard impacted stools can sometimes cause the walls of the colon to form blind outpockets called diverticula which can periodically inflame. So what makes cellulose different from starch? Isn’t it made of glucose? Well it is but the glucose monomers are organized in an interesting fashion. The orientation of the glucose molecules alternates. So if the first one is right side up, the next one is upside down and then the next is right side up and the next one is upside down. Apparently this is a tricky arrangement for an enzyme to break.
The statement in the given question that presents a condition of the Hardy-Weinberg principle is that random mating occurs. The correct option among all the options given in the question is option "C".
There are definitely certain
conditions under which the Hardy- Weinberg principle occurs and they are when
there is no gene flow, no mutations happen, no generic drift occurs and random
mating occurs. This principle also states a very important aspect and it is
that genotype and allele frequencies will always remain constant from one
generation to another if there is absence of other evolutionary inflrnce.
The answer to the question stated above is non-disjunction.
So Mendel got roughly 75% yellow and 25% green in f2. This means that f1 contains all heterozygous genes, as shown below
Y y
Y YY Yy
y Yy yy
Summary: 75% YY or Yy, 25% yy
Which means that green (y) is a recessive phenotype, while yellow (Y) is a dominant phenotype, since plants with heterozygous genotype Yy express the yellow trait.
Eukaryotic cells are theorized to have evolved from prokaryotes called the endosymbiotic theory. This explains that the most primitive eukaryotic cell engulfed a prokaryotic cell (by the process of phagocytosis) that is capable of cellular respiration and another prokaryotic cell that is capable of photosynthesis. These prokaryotic cells eventually became organelles and these organelles are the mitochondria and the chloroplast.
