I've been reading about cohesin lately, and I'm confused about the head subunit interactions. I've read a few papers, and also found this nice figure from wiki that demonstrates the crux of my que…

We know that some animals do not have real teeth consisting of enamel and dentin. Many have tooth-like structures but different constitutions. However, there are animals that have neither, and have developed different mechanisms to obtain food. The best known of these is the anteater, which has long and sticky tongue, but unlike other mammals, has no teeth.

How many coronavirus (or other common virus) particles are in the body at the peak? How far it multiplies? Are there billions, trillions or other number of them?

Describe the structure and function of antibodiesAn antibody, also known as an immunoglobulin (Ig), is a protein that is produced by plasma cells after stimulation by an antigen. Antibodies in these bodily fluids can bind pathogens and mark them for destruction by phagocytes before they can infect cells.

Our biology teacher says that peacocks will soon become extinct because of bigger and bigger (and heavier and heavier) tails. Why natural selection did not eliminate sexual selection?

This is pretty specific question maybe. Anybody have an estimate? For Toll Like Receptors there are something like 10… http://www.jbc.org/content/276/4/2551.long I'm only finding NOD1 and NOD2…