Sponges have specialized cells and an endoskeleton, but they lack tissues and body symmetry. ... They include jellyfish and corals, both of which have radial symmetry. All cnidarians have nematocysts, and many are bioluminescent. They may exist in medusa and/or polyp form.
Answer:
Answer D
Explanation:
improved water habitats for human recreation
Answer:
C. Population shrinks; 15 birds in the end
Explanation:
Let us understand some of the given terms;
immigration is a form of migration in which organisms comes into a territory.
emigration is a form of migration in which organisms leaves a place
population is a group of organisms of the same species
Given:
Population = 21 birds
Immigrant = 3 birds
Emigrants = 9 birds
Population change = total number of birds + immigrant - emigrants
= 21 + 3 - 9
= 15 birds
The population will shrink giving 15 birds in the end
When it freezes ..................
