The black widow spider is an invertebrate. Its skeleton system hangs outside its body. The only difference between a vertebrate and invertebrate is the presence of backbone or a similar kind of structure with in the body. In case of black widow spider, the internal structural element is missing. Its skeleton system can be classified as exoskeleton.
Answer:
<em>B: The drug is a small charged molecule</em>
Explanation:
Substances can passively diffuse in and out of the cell via the cell membrane in two ways;
- Simple diffusion
- Facilitated diffusion
The cell membrane allows small molecules or ions to freely diffuse across it in response to concentration difference between the inner and outer parts of the cell membrane. This is known as simple diffusion.
In facilitated diffusion, special proteins in the cell membrane, known as channel/carrier proteins binds with molecules and facilitates their diffusion across the cell membrane by carrying them through special channels in the membrane.
Hence, to support the alternative hypothesis that the new drug will exhibit simple diffusion across the plasma membrane, the drug should be a small charged molecule.
<em>Correct option: B</em>
<span>Since alkylating agents work to prevent the cell from replicating its genetic material, the cell would most likely stop at the interphase checkpoint, which is the phase before mitosis (which consists of prophase, metaphase, anaphase, and telophase). During interphase, the cell replicates its genetic material (DNA), but this would be prohibited by alkylating agents.</span>
Well during an enzyme catalyzed reaction the enzyme bonds with a specific substrate at the active site. This is called an enzyme-substrate complex. The substrate is converted into a specific product, but the enzyme remains unchanged. Enzymes accelerate reactions by factors of at least a million.Enzymes are not used up in a chemical reaction. Usually, the enzyme will "reset" and be ready to use in another reaction. This is due to the fact that enzymes are proteins, and their shape is what they use in a chemical reaction. Initially, the enzyme has a particular shape. Something happens to the enzyme (usually a shape change, called a conformation change, brought on by the presence of two or more chemical reactants), and the enzyme catalyzes the reaction. After the reaction is catalyzed, the product is released, and the enzyme can "relax." This means it goes back to its normal shape, ready to do it all over again
Hope it helps
Answer: B. Water molecules slow down until they begin to bond together.
Explanation: When water is cooled, energy is removed from the system, and the molecules begin to slow down. When the molecules have slowed suciently, their collisions are no longer energetic enough to overcome their electrostatic attraction, and they begin to bond together. The other answer choices are inaccurate. Since ice is less dense than water, high pressure compresses the ice and actually causes it to melt. (Compression has no effect on water volume.) Cooling has no effect on the shape of individual water molecules.
