The beginning of the Eocene Epoch Era.
Answer:
Disease and Famine
Explanation:
If there is a disease that affects a type of plant, having other types of crops to rely on could save one from starvation. Also, only planting one crop in an area can change the pH and nitrogen levels in negative ways, so that eventually no plants can grow there. Not to mention the obvious balanced diet needed for a healthy body.
Answer: Read explanation
Explanation: there’s actually no similarity at all. A cell membrane is made of phospholipids, globular proteins, glycolipids, glycoproteins, and cholesterol, and has passages that serve explicitly for passive and active transport of materials through it.
The skin is made of cells and dead keratin and serves as much as possible to prevent most substances from moving through it. It’s “designed” for toughness and distensibility, not for selective permeability.
All in all, the difference is that a cell membrane is explicitly and only for the passing and transport of materials through it, and the skin in the skin is made to be tough and durable, almost the opposite of a cell membrane.
Answer: the correct answer is d. all of the above must happen for defecation to occur.
Explanation:
In response to the distention of the rectal wall, the receptors send sensory nerve impulses to the sacral spinal cord. Motor impulses from the cord travel along parasympathetic nerves back to the descending colon, sigmoid colon, rectum, and anus. The resulting contraction of the longitudinal rectal muscles shortens the rectum, thereby increasing the pressure within it. This then opens the internal sphincter.
When a virus attacks a cell, it kills the cell and the virus multiplies to spread throughout the body
