1 -
If polar bears feed on seals, they have a prey-predator relationship. There isn't much to explain here.
Answer:
A.
2 -
If polar bears hunt less (these are probably quarternary consumers), and if we consider biomass as the total weight of animals in a specific space, we just have to analyse the options.
The one that makes most sense to us is, less biomass in the quarternary level. That's because some polar bears will die, and the others that aren't dying will be eating less, decreasing the total weight.
Answer:
A.
3 -
So, if we increase the reserve area, so will its capacity, because the capacity of species is directly proportional to the area.
If a disease began killing individuals, the carrying capacity will remain the same, because the reserve will still be able to carry the same amount of individuals as before. What will be changing is the number of individuals.
Answers:
Increase; remain the same.
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If we increase the population of small fish (primary consumers), there will be an increase in the population turtles and large fish (tertiary consumers) since they'll have more food. - NOTE: there is no available option for this.
Also, the population of water fleas and aquatic insects (primary consumers) will decrease, since there will be more small fish (secondary consumers) to prey on them.
So, if there'll less water fleas and aquatic insects (primary consumers), the population of algae (producers) will increase.
Answers:
Increased producers; decreased primary consumers
Hope it helped,
BioTeacher101