The complete question is :
The success of plants extending their range northward following glacial retreat is best determined by _____.
A) whether there is simultaneous migration of herbivores
B) their tolerance to shade
C) their seed dispersal rate
D) their size
Answer: The seed dispersal rate
Explanation:
The seed dispersal can be defined as the movement of the seeds away from the parent plant. The ability of the plant to extend is completely dependent on the ability of the plant to disperse its seeds.
Plants have very limited ability, they need vectors to carry its seed from one place to another.
The biotic and abiotic vector both are involved in carrying the seeds which helps in expansion of the trees.
hence, the correct answer is option C
Top-down effects imply control through predation, including fishery, while
bottom-up effects imply control through food abundance, often thought to be driven by climate or nutrient load.
<h3>What is Top down regulation ?</h3>
The top-down effect refers to a higher trophic level influences the community structure of a lower trophic level through predation.
<h3>What is Bottom up regulation ?</h3>
The bottom-up effect means that a lower trophic level in the biological network affects the community structure of higher trophic levels by means of resource restriction
Learn more about Top down and bottom up regulation here:
brainly.com/question/18996262
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Answer:
habitat
Explanation:
habitat is part of the ecosystem
niche describes ahow different organisms are linked
The answer is osteoclasts
Emperor penguins need lungs to breathe. In penguin lungs, air never stops. ... Once the air goes farther into the trachea it splits into two different directions into both lungs. To get the oxygen into the blood cells, it must come "within small distance of the penguin blood cells".