How does the process of photosynthesis affect the atmosphere? A. Photosynthesis removes oxygen from the atmosphere and replaces it with CO₂.
B. Photosynthesis changing water vapor and nitrous oxide into atmospheric oxygen.
C. Photosynthesis is the main source of oxygen in the atmosphere.
D. Photosynthesis adds small amounts of oxygen to the atmosphere.

C

Explanation:

The result of Photosynthesis is Oxygen which goes into the atmosphere that were breath in. All the others are wrong.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.