they are caused by mutation. the best example of it are human blood groups.
The correct answer is A.
Oswald Avery applied several biochemical techniques to large cultures of bacteria in order to extract and purify the "transforming principle". Their experiments showed that most probably the "transforming principle" was DNA. One of the observations leading to this conclusion was that enzymes that degrade proteins or RNA (such ribonucleases) had no effect on the "transforming principle". On the contrary, enzymes degrading the DNA destroyed the extract's transforming capacity.
Answer:
many
pollution by dumping chemical that are harmful to the animals
littering by plastic
accidentally introducing invasive species
over fishing
it lowers the biodiversity of the aquatic ecosystems living there
Explanation:
Answer:
they are Na+, K+ and Ca2+ ion channels.
Explanation:
Ionotropic acetylcholine receptors are also called nicotinic acetylcholine receptors because beside acetylcholine (Ch) they respond to nicotine. These receptors are primary receptors in muscle for motor nerve-muscle communication that controls muscle contraction.
Two molecules of ACh are required for receptor to open. Since the receptors are linked to ion channels, the channels open. Opening of the channel allows positively charged ions to move across it: sodium enters the cell and potassium exits.
Answer:
Interactions between biotic and abiotic components regulate carbon dioxide and water levels.
Explanation:
Abiotic factors include temperature, water, humidity, etc; while biotic factors include all the forms of life. These factors interact in the ecosystem to maintain its homeostasis. For example, during the photosynthesis, plants use the energy of the sun water and carbon dioxide to produce food (carbohydrates) and this process converts carbon dioxide (CO2) to oxygen, which is critical for maintaining the homeostasis of the ecosystem.
