Answer:
The presence of ozone enabled organisms to develop and live on the land. Ozone played a significant role in the evolution of life on Earth, and allows life as we presently know it to exist. These atoms combined with remaining oxygen (O2) to form ozone (O3) molecules, which are very effective at absorbing UV rays which could be injurious to organism existence
Explanation:
Answer:
The correct answer is eukaryotes engulfed photosynthesizing prokaryotes
Explanation:
The endosymbiotic theory or symbiogenesis is an evolutionary theory that traces the origin of eukaryotic cells from prokaryotic organisms. It explains that some of the organelles (Mitochondria and Chloroplasts) in eukaryotic cells evolved from free-living prokaryotic microbes which were ingested or engulfed. The ingested prokaryotic cells survived within the organism and developed a symbiotic relationship.
According to the theory, chloroplasts was formed when eukaryotes engulfed photosynthesizing prokaryotes and mitochondria was formed when bacteria capable of aerobic respiration were engulfed.
Answer: B. Water breaks down into oxygen molecules for respiration.
Water is the required for photosynthesis, a process by which plants (terrestrial and aquatic) makes their food by utilizing water as a reactant to produce oxygen and glucose as product. The glucose act as a source of energy for conducting various metabolic processes in plants but oxygen is released in the air.

This oxygen is necessary for terrestrial and aquatic animals for respiration. Therefore, water breaks down into oxygen by the process of photosynthesis, hence water plays important role in respiration in living beings.
I believe A is the most correct (i assume it's about antibiotics - they actually DO harm our immune system in some way).
B is partially correct because, the colds indeed should be treated by anti-viral medication (because the virus is a cause of typical cold) but using antibiotics during recovery is needed only when an additional bacterial infection occurs as a complication after the viral infection. and it doesn't happen very often.
C - what works? antibiotics doesn't work for viral infections (colds). anti-viral medication do.
D i won't discuss.
I am sorry for a so long answer. but your question is so linguistically twisted that i am not sure which of the following choices is actually correct because of a big amount of mistakes.
Answer:
to ensure that the two individuals are of the same species
Explanation:
It also involves stereotyped behaviours. Courtship behaviour informs a potential mate that the intention is breeding and not aggression.
Please give brainliest