Answer:
<em>The correct option is d) once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.</em>
Explanation:
In the field of biology, the all-or-nothing law can be described as a principle which focuses on the strength with which a nerve or muscle fibre responds to a particular stimulus, this strength being independent of the strength of the stimulus. The functioning of the impulse is just like the trigger of a gun. The more the force of a stimulus, the more will be the intensity of the nerve impulse.
D. Mitosis and Cytokinesis
Cells are combined in a structure called tissue wich have the same properties like the cells wich are formed by.
Answer;
-Zygote
When sperm and ovum unite at conception, a zygote results.
Explanation;
-Conception occurs when a sperm cell from a fertile man swims up through the vagina and into the uterus of a woman and joins with the woman's egg cell (ovum) as it travels down one of the Fallopian tubes from the ovary to the uterus.
-A zygote is the union of the sperm cell and the ovum. Also known as a fertilized ovum, the zygote begins as a single cell but divides rapidly in the days following fertilization. After this two-week period of cell division, the zygote eventually becomes an embryo.