Answer:
B (active transport using ATP)
Explanation:
Movement of substances normally occur in the direction of concentration gradient/difference i.e. the difference in concentration of a substance across a membrane. Letting molecules diffuse or pass down their concentration gradient does not require energy but pumping those molecules against gradient requires energy in form of Adenosine triphosphate (ATP). This process is called Active transport.
In order to perform certain cellular processes, cells need to move substances from their surroundings into the cell across their cell membrane. Moving this substances against the concentration gradient between the cell membrane and its extracellular fluid requires energy (ATP).
An example is the sodium-pottasium pump employed by animal cells in which they expend energy to move K+ molecules into the cell and Na+ molecules outside the cell against the concentration gradient of their cell membrane and extracellular solution.
A eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes. However, unlike prokaryotic cells, eukaryotic cells have a membrane-bound nucleus.
*Got this info from the internet*
The tennis ball. Because of less mass
The joint cavities are composed of two bones covered by the hyaline cartilage. The joint cavities allow for the movement of the two articulated bones. The fibrous and the cartilaginous bones have no joint cavities as they require little to no movement. These joints are connected tightly by the cartilage, such as in the spinal column. if the joint cavities were present in these joints, then these structures will not be held tightly and hence, they could not perform their function well.
Hence, the answer is 'the fibrous and cartilaginous joints will not be able to perform their function if they had joint cavities'.