Answer:
Means to increase drag and prevent sinking is the correct answer.
Explanation:
Plankton avoid sinking by increasing their surface area and decreasing their density. Spines slow down sinking by adding surface area without increasing density. Defense against predation would be to sing below. Not the opposite.
The heart is a muscle, therefore, if the cardiac muscles stopped contracting, the result would be the ceasing of heart function. That would lead to death, as blood wouldn't be pumped throughout the body. Homeostasis would therefore be interrupted.
Antibiotics can be used to treat sickness
Cyanobacteria obtain their energy through photosynthesis