Carbohydrates or starch polymers are formed by condensation which bonding together of monomers (monosaccharides) and loosing a molecule of water in the process. These polymers include glycogen and starch and they may be formed by aggregation of monomers in the cells assisted by enzymes. Fat polymers are formed through the attachments of monomers such as alkyl or allyl chains, aliphatic or aromatic to one of the three hydroxyl groups of glycerol, consuming one or two or all 3 hydroxyl groups of glycerol now called mono, bi or triglycerides respectively. Proteins polymers are compounds derived from amino acids monomers. Amino acids have carboxy snd sn smino group on the same carbon. The amino acids polymerize by condensation to form protein chains. Size of the biomolecules is normally based on the molecules of concern, in this case i would state that fatty acids or fatty polymers usually have 4 to 28 carbon atoms, Starch contains about 30 glucose units (amylopectin) while number of amino acid units in a protein depends on the sequences of the bases in the gene that encode a particular protein.
The main use of a beak is for feeding. Since beaks are mainly used for feeding, the variation in beak shape and size mostly has to do with the food that each species prefers. Some beaks are made for digging seeds out of shells while others are designed to dig deep into the ground to pull out prey items.
The cerebral cortex consists of neurons, nerve fibers and neuroglia. The cerebral cortex (neocortex) consists of six layers (in human the primitive arrangement into three layers persists only in the olfactory cortex and the cortical part of the limbic system in the temporal lobe).
Pat has likely been in the sun longer than John, since she/he works outside. Since she is outside longer, her/his skin has learned to adapt to it by producing more melanin to protect her/him. John doesn't go outside as much so his skin doesn't need to adapt to sun rays.