Answer:
Proteins and lipids exist as separate but loosely attached molecules that can move around
Explanation:
Cell membranes are mainly composed of lipids, proteins, and also carbohydrates. Phospholipids are the most abundant type of lipid and the main constituent of the cell membranes. Membrane proteins are divided into two types according to their interactions with the cell membrane: 1-integral (intrinsic) and peripheral (extrinsic) proteins. These peripheral proteins are loosely attached by ionic bonds or calcium bridges with the phosphate heads of the phospholipids; whereas integral membrane proteins contain side chains that interact with fatty acyl groups of the phospholipids. Cell membrane fluidity indicates how easily lipids (e.g., phospholipids and cholesterol) and proteins (e.g., intrinsic proteins) diffuse laterally in the cell membrane. This fluidity is affected by the amount of cholesterol, temperature, and the ratio of unsaturated to saturated fatty acids. Saturated fatty acids have no double bonds in the hydrocarbon chain, whereas unsaturated fatty acids have at least one double bond (these double bonds increase fluidity). Moreover, higher temperatures increase membrane fluidity, whereas cholesterol molecules function to regulate membrane fluidity: at high temperatures cholesterol molecules stabilize the membrane, whereas at low temperatures intercalate between phospholipids, thereby preventing them from clustering together.
<span>The correct answer is C. The Golgi apparatus. This is the packaging center of the cell. It is responsible for receiving cell products and transporting them within vesicles either within the cell or to surrounding cells. Lysosomes are the trash collectors of the cell, responsible for processing wiaste. The cell membrane makes up the cell's enclosure and selectively allows material into and out of the cell. The endoplasmic reticulum contains ribosomes and is responsible for assisting in protein production.</span>
Answer:2
Explanation: Sperm cells in plants are found inside the pollen grain. When the pollen grains fall on the stigma, the pollen raptures and forms a pollen tube then the sperm cells pass through the pollen tube to the ovary.
