20.4 21.3 are the correct answers
D. Polarity and size.
<span>The size, polarity, and charge of a substance will determine whether or not the substance can cross the cell membrane by diffusion. The cholesterol was an example of a lipid, and is highly soluble in the nonpolar environment of the lipid bilayer. You saw, in the animation above, the cholesterol freely passing into the hydrophobic environment of the membrane. Cholesterol distributes freely in the membrane and then some fraction will dissolve in the aqueous environment of the cytoplasm. Water, on the other hand, while polar, is small enough to cross the membrane at a slow rate. Note that specialized transport proteins in certain cell membranes can provide a channel for the water, greatly increasing its rate of crossing the membrane. The lipid bilayer is much less permeable to the ion, because of its charge and larger size. As a general rule, charged molecules are much less permeable to the lipid bilayer.</span>
Answer:
<h3>Maintenance of ionic balance.</h3>
Explanation:
Synovial fluid is a viscous fluid found in the cavity of synovial joints. In terms of appearance the synovial fluid appears clear
, Colorless (pale yellow)
, viscous, microbes free.
Synovial fluid has following functions in our body
a) shock absorption
b) nutrient distribution
c) lubrication of the articular surfaces
d) waste disposal
nucleus
is the power house of a cell
Wastewater is water that contains the waste from homes and industries.
<h3>What is wastewater?</h3>
Wastewater refers to water that contains waste products. Waste water can also refer to water that have been used for several purposes and produced as a by-product.
The primary sources of waste water include:
- from homes
- from agricultural and farming activities
- and industries.
Therefore, it can be concluded that waste water is water that contains waste from homes and industries.
Learn more about wastewater at: brainly.com/question/25085634
