Answer:
B cell membranes protect a cell,and cell walls do not
For #1, the last choice is correct. A geocentric model means that the earth is the center of the universe while all other bodies orbit around it. A heliocentric model means that the sun is the center of the inverse while the other bodies orbit around it. The shared feature is that the other bodies in space move in circular orbits.
For #2, the first answer is correct. When the moon is between the earth and the sun, positions X and Z are being pulled by the moon’s gravitational force, creating high tides at these places. However, positions W and Y are experiencing low tides because no gravitational pull is making them high.
Phobhos and dhemos are the two moons of mars.
The Earth is layered because of the difference in the density and the pressure experienced by the elements. The denser layers tend to be closer to the center and the lighter layers float on the top. The differences in the pressure experienced by these layers also keeps them separated. The pressure experienced by the center of the Earth is greater than the upper layers, and hence, the core is in liquid form because the pressure is not enough for it to remain in the solid state.
This led to the layering of the Earth's surface.
C. Mutagens causes mutations.
