<span>a method of measuring net migration between two dates by comparing the estimate of total population with that which would have resulted solely from the components of birth and death, with the residual attributable to migration</span>
Answer: Cell
Explanation:
The cell is the structural and functional unit of life. It is the the most basic level. A life starts from a single cell.
When a male and female gamete(germ cell) fuse together they form zygote. Firstly it is a single cell surviving inside the mother's womb.
Then differentiation takes place and the cell keeps on dividing to form different tissue layers and then organs form which makes a complete baby. Hence, zygote and germ cell are cellular level of organization.
Answer:
b option is the correct answer
A volcanic bomb is a mass of molten rock bigger than 64 mm (2.5 inches) in diameter, formed when a volcano ejects viscous fragments of lava during an eruption. They also cool down into solid fragments before they land on the ground<span>.</span>