Answer:
So 1 ml=1 cm^3, so 40ml is 40 cm^3
D= m/v
density = 30/40
Density of oil is 0.75 g/cm^3 (which is verified as oil is less dense than water hence floats on it)
Explanation:
It is C sensory or D not quite sure.
Answer: Option B
Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical barriers that are always ready to protect the body from infection.
Example: Skin and mucous membrane.
Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.
Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.
So, skin and mucous membrane are the first line of defense.
Thin, flexible barrier around a cell; regulates what enters and leaves the cell
- contains the cytoplasm (all interior cell organelles and the cytosol) - allowing the chemical reactions in the cell to occur
<span>- semipermeable (or selectively permeable) - allows certain substances in, keeps others out </span>
<span>- offers limited protection</span>
