Africa, Australia, etc because they are the oldest ones.
<span> After fertilization, the </span>zygote<span> undergoes cleavage to form the blastula. The blastula, which in some species is a hollow ball of cells, undergoes a process called gastrulation, in which the three germ layers form.</span>
Answer: Ecosystem
Explanation:the ecosystem is a network of organisms,their environment and their interaction in a particular place.it involves the interaction between the different organisms that make up a community and it's non-living environment.
The living organisms share resources with each other and include autotrophs, heterotrophs,decomposers; trees,grasses,insects, animals etc.
The non living components include rainfall,air water etc
Just like the name suggests it's the second consumer in a food web or food chain that eats the primary consumers or the producers.
Answer: b. Necton
Explanation:
Necton is the term used to refer to aquatic organisms that are able to swim against the current of the water they are in. For this reason they are called "actively swimming" organisms. Aquatic plants that are unable to move against the current are called Plankton.
Fish, whales and dolphins are able to move against the current and so are classified as Necton. It is worthy of note however, that some organisms are able to transition from Plankton to Necton as they mature.
