Answer:
<em>Many scientists opposed the "cell theory" </em>when it was first introduced because they believed that <u>even "non-living matters" could produce or generate a living tissue.</u> This was called<em> </em><em>"spontaneous generation."</em><em> </em>The appearance of the fly's larva<em> (maggots)</em> on meat supported this belief of theirs.
It was Louis Pasteur who was able to disprove this concept.
Explanation:
The discovery of cell came about when the microscope was invented. It was first discovered by Robert Hooke, an English natural philosopher in the <em>1600s</em>. However, he wasn't really sure about the structure and function of the cell during his time. It was Anton van Leeuwenhoek, a Dutch scientist, who proposed that "<em>motility"</em> is a quality of life.
Developing the cell theory was credited to Theodor Schwann and Matthias Schleiden.
<span>In the question re-posed as one of the answers the best solution is option D
That is to say Unlike mammals fish ... utilize gills for gas exchangeIn the question re-posed as one of the answers the best solution is option D
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Answer: The human heart is a four-chambered muscular organ, shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of mid-line. The heart is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane.