A semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by diffusion—or occasionally by more specialized processes of facilitated diffusion, passive transport or active transport.
Answer:
What stages of aerobic respiration needs oxygen to happen?
The Krebs cycle and the electron transport system
B ecosystem. They include abiotic factors and biotic factors.
Unconformities occur when erosion wears away rock, or when rock deposits are never formed hope this helps :3