Answer:Small hydrophobic molecules and gases like oxygen and carbon dioxide cross membranes rapidly. Small polar molecules, such as water and ethanol, can also pass through membranes, but they do so more slowly.Semipermeable membranes, also termed selectively permeable membranes or partially permeable membranes, allow certain molecules or ions to pass through by diffusion.
Explanation: hope that helps
The natural flow of rivers can be affected by several factors, such as building dams to provide drinking water, pumping of groundwater, climate change, and building of lands that change how natural water runs into surfaces and into rivers. All of these also disrupt the balance of ecosystem in the area.
Answer: A recessive allele is only expressed if the individual has two copies and does not have the dominant allele of that gene.
Explanation: Recessive alleles are represented by a lower case letter, for example, a. The allele for blue eyes is recessive.
Diffusion allows the exchange of substances; the entry of oxygen, proteins, etc into the cell and the removal of waste substances.
Proxima Centauri is the nearest star to Earth.
