Answer:
D. all of the above
Explanation:
Biome refers to a large and relatively distinct terrestrial region having similar climatic conditions regardless of where it occurs on Earth. The characteristic climatic conditions (temperature and precipitation being the most important ones) and soil type of each biome type determine the type of plant species found there. Therefore, each biome is characterized by specific flora.
For example, a desert biome is a temperate or tropical biome characterized by a lack of precipitation, seasonal variations in temperature and poor soil type with low organic matter that limits plant growth. Desert biomes have only the plant species that can survive these harsh conditions.
Answer: C
Explanation: The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days.
The cell membrane functions as a selective barrier. We call these kind of membranes as differentially permeable or semi permeable membrane. It can decide what substances can pass in and out. Therefore it can surround the cytoplasm (which is the inside of a cell) to separate the cell's content from the surroundings.
A basic definition of an ionic compound is that they are molecules that consist of charged ions. These ions have opposite (both negative and positive) charges. On the other hand, covalent compounds are non-metals which are bound together, and consist of two electrons that are shared between two atoms.