Answer: Seastars prey on mussels and shellfish which would otherwise have no other natural predators. Herbivorous fish like the butterflyfish pictured to the left prey on marine algae. Without this crucial predator-prey balance, the algae would over-grow, which would then kill coral, as they compete for the same resources.
Answer:
B. oxygen and glucose
Explanation:
Oxygen for respiration and glucose for energy utilization
<u>Answer: </u>
A sample initially contained 150 mg of radon-222. After 11.4 days only 18.75mg of the radon-222 in the sample remained where 3 half-lives have passed
<u>Explanation:</u>
Given, the initial value of the sample,
= 150mg
Final value of the sample or the quantity left, A = 18.75mg
Time = 11.4 days
The amount left after first half life will be ½.
The number of half-life is calculated by the formula

where N is the no. of half life
Substituting the values,


On equating, we get, N = 3
Therefore, 3 half-lives have passed.
Answer:
Potassium phosphide (K3P)