Small intestine is modified due to the presence of micro villi which has ability to increase it's size
Answer:
Because they can only reproduce in a living cell
Explanation:
Virus is an organism that is incapable of replicating on its own without a living host. A virus infects a living host and makes use of Its replicational ability to produce new virions. A virus consists of a genetic material surrounded by a Protein called CAPSID. It does not possess the characteristics of other living organisms.
This means that it does not carry out any of the features a living cell undergoes e.g reproduction, respiration etc. Due to this reason, it is not classified as a living thing. They don't possess organnelles that carry out this peculiar functions.
A virus is considered a peculiar microorganism because it can only live and reproduce in a living host cell.
Answer: Substances that are protein based cannot cross the lipid cell membrane, but can exert their effect by binding to the proteins based receptors present on the lipid bilayer.
Explanation:
Hormones such as calcitonin , Parathyroid hormone and pituatry horomones are proteins and water soluble.They cannot cross lipid bilayer but can bind to ligand binding protein receptors.
These receptors are protein macromolecules that are specific in nature for specific hormones.
After binding to the receptors, these hormone-recpetor complexes activate second messengers and regulate the downstream effects.
Answer:
small intestine
Explanation:
Umbilical. The umbilical region contains the umbilicus (navel), and many parts of the small intestine, such as part of the duodenum, the jejunum, and the illeum. It also contains the transverse colon (the section between the ascending and descending colons) and the bottom portions of both the left and right kidney.
