Answer:
A. Their bodies tend to take in too much water.
Explanation:
Osmoregulation is the maintenance of osmotic concentration inside the body cells and in the extracellular fluid by controlling the amount of water and salts. Organisms living in water can be divided into two groups: Some are osmoconformers which change the osmolarity of body fluids with respect to the surrounding medium. Some are osmoregulators which do not allow change in internal osmolarity and try to maintain it by various means.
If as osmoregulator is placed in fresh water environment then their body is hypertonic to their environment. Osmosis will occur which is the movement of water from low solute to high solute concentration. Thus the problems faced by such organisms would be:
- Entry of excess water
- Loss of body salts to outside.
Adaptations in such organisms would be:
- Body cover such as scales or adipose covers
- They do not drink more water
- Excess water is eliminated as dilute urine
- Special cells called ionocytes or chloride cells help in active uptake of sodium ions and chloride ions.
Answer:
Explanation:
Botulinum toxin (Botox) is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species
Botulinum toxin commonly acts by binding to high-affinity recognition sites on the cholinergic nerve terminals and decreasing the release of acetylcholine, causing a neuromuscular blocking effect. Through this mechanism, muscle movement is inhibited in the area it is injected to.
Variations are important to natural selection because if every species was the same and natural selection did not like them that whole species would go extinct, if there is a variety of that species it will serve because natural selection will only take out the type of that species it does not like, for example sharks! There are many types of sharks. If all sharks where put into fresh water and they where all the same type they would all die but since there is a variety the sharks that can live in fresh water live and the ones that don’t die.
