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.
Olafactory bulbs because it has to do with nerve signals and neurons. Brain because it is the center of the nervous system and the closest to the nose in terms of the nervous system.
Answer:
B. polio—polyhedral shape
Explanation:
A virus is a small parasite which cannot self reproduce. For a virus to produce more viruses, it uses the cell to duplicate itself. Viruses contain RNA or DNA as their genetic material.
Poliovirus is composed of an RNA genetic material and it is responsible for Polio. Polio leads to paralysis and is transmitted through contaminated water or food, or contact with an infected person.
The shape of Poliovirus is formed by polyhedral (many-sided) shell or capsid.
Yes, this is true, and it is actually one of the organisms driving evolution! Some organisms develop mutations that are actually beneficial (better eye-sight, for example) and they're more likely to pass those to their children that individuals without those mutations!
