Answer:
The two membranes pull apart a little and create a small pocket or sack of air. As the developing bird grows, it breathes in oxygen from the air sack and exhales carbon dioxide. Several thousand microscopic pores all over the surface of the egg allow the CO2 to escape and fresh air to get in.
Explanation:
U 2 can help me by marking as brainliest.......
I would say A
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Answer:
1) Immunogene
2) immunoglobulin / antibodies
3) Antigen
4 Vaccine
Explanation:
Vaccine: vaccines are made from a weakened or killed form of a Disease causing micro organism
Antigen : these are toxins or foreign substances that causes or stimulates immune response in the body
Immunoglobulin: they are also known as antibodies, they are protein produced by the by the white blood cells to combat foreign substances
Immunogene: these are molecules or substances that have the capability of stimulating immune response by the immune system of an organism.
Answer:
A
Explanation:
Because b,c,d can be proven
while a is not proven
