Question

1. If a single-celled saltwater organism is placed in freshwater, it will not be able to survive. Which statement explains why this is true?

A. The organism’s cell will absorb too much water through osmosis.
B. The organism’s cell will release too many hydrogen ions through diffusion.
C.The organism’s cell will release too much water through facilitated diffusion.
D. The organism’s cell will absorb too many sodium ions through osmosis.

2.Which must be true of any scientific hypothesis?
A must be testable
B must undergo peer review
C must be approved by professionals
D must be proven correct by research

Answer 1

A saltwater organism placed in freshwater will likely perish due to excessive water absorption by osmosis, which can dilute cell solutes and cause the cell to burst. Separately, for a hypothesis to be considered scientific, it must be testable, allowing for potential support or contradiction through experimental and observational methods.

Step-by-step explanation:

Osmotic Pressure and Cell Survival

When a single-celled saltwater organism is placed in freshwater, it experiences a stress on its osmotic balance. The correct statement explaining why such an organism will not survive is A. The organism's cell will absorb too much water through osmosis. Osmosis is the movement of water across a semi-permeable membrane, from a region of low solute concentration to one of high solute concentration.

This influx of water can dilute cell solutes, impairing cell function, and can cause the cell to swell and potentially burst if not managed by some form of cellular regulation such as a rigid cell wall or a contractile vacuole, as seen in some freshwater organisms. However, most saltwater organisms lack these mechanisms and, therefore, do not survive in lower-salinity environments such as fresh water.

With respect to the nature of a scientific hypothesis, the essential characteristic of any hypothesis is that it must be testable (Answer A). A hypothesis requires a framework that allows for experimentation and observation to support or refute the proposed explanation. While peer review, approval by professionals, and research are parts of the scientific process, they do not determine the fundamental nature of a hypothesis.

Answer 2

1. The correct answer would be A. The organism’s cell will absorb too much water through osmosis.

If a single-celled salt water organism is placed in freshwater, then the freshwater would act as hypotonic solution (low solute concentration) as compared to the cytoplasm of the cell.

Consequently, water from outside will move into the single-celled organism by the process of osmosis. Excess of water can result in the bursting of the cell. Hence, it can not survive in the fresh water.

2. The correct answer would be A must be testable.

A scientific hypothesis refers to the proposed or possible explanation for occurrence of any phenomenon.

For example, occurrence of cold can be reduced by consuming vitamin C.

A scientific hypothesis must be testable and falsifiable.

There should be a scientific method(s) or observations which could agree or disagree with the proposed hypothesis.