Answer:
X is negative heterotropic modulator
Explanation:
In allosteric regulations, modulators are molecules that causes a change in the conformation of an enzyme, hence, resulting a change in enzyme activity. It can lead to a decrease or an increase of the enzyme. When a molecule decreases the enzyme activity it called a negative modulator, when it increases or activates the enzyme activity, it is called a positive modulator.
A positive or negative modulator can either be homotrophic (substrate acts as modulator) or heterotropic (another ligand acts as modulator).
In the example above, X is negative heterotropic modulator, because the modulator is different from the substrate and it also decreases the enzyme activity.
embryonic stem cells could serve as a model to evaluate the physiological effects of environmental pollutants efficiently and cost-effectively.
Cells are the basic structural, functional, and biological unit of all known living organisms. Cells of various types have different functions but the generalized cell functions include movement of substances across the cell membrane, cell division to make new cells, and protein synthesis. So, the answer is D, cell can conduct many tasks, including duplicate themselves, convert energy and selectively exchange materials.
Answer: Food, Water, Shelter and Space
Explanation: In the natural world, limiting factors like the availability of food, water, shelter and space can change animal and plant populations. Other limiting factors, like competition for resources, predation and disease can also impact populations.