Answer: Options A, B, C, D at correct
Explanation:
Cnidarians are a branch of invertebrates characterised by by a radially symmetric body including a saclike internal cavity and nematocysts; stinging structures that aids in feeding. They are also known as coelentrates. They are diploblastic (2 body layer). They also reproduce asexually by various mean including budding. Example include sea anemones, hydra, corals, jellyfish etc
They are different ranks in a taxonomy hierarchy. The genus is more exclusive than the phylum.
Order:
Domain,
Kingdom,
Phylum,
Class,
Order,
Family,
Genus,
Species
Oxygen is an abiotic factor that is beneficial by-product of primary production.
<u>Explanation:</u>
The non living parts of an ecosystem that mainly affects the living organisms in it are called as an abiotic factor. These can include soil, temperature, water, oxygen and sunlight. The major energy source in earth is Oxygen which is abiotic factor.
It is very essential for the photosynthesis process to take place. Here, the plants converts water and carbon dioxide into oxygen and sugar. This becomes food for plants. Then these plants are eaten by animals. Thus oxygen is an important and beneficial by-product of photosynthesis. Oxygen is also very important for the survival of human beings.