fossils because these rocks are formed on the Earth surface, under the water, at very low temperatures and pressures.
It enters and or leaves it through two separate mechanisms. One is the Sodium potassium pump which works as a gatekeeper for sodium and potassium ions that go in and out of the cell. This is active transport. Another way how it enters/leaves cells is with the help of passive ion channels where they can cross without much difficulty.
Answer:
19-22 days after fertilization of egg by sperm
Explanation:
The heart is the first organ to be formed in a developing embryo. This is because it is a vital organ and responsible for the circulation of blood (with oxygen and nutrients) to the other developing tissues. It begins to be formed at around 18 days from fertilization and begins to function after day 21.