If the sperm cell fertilises the ovum, and implantation does not occur, then the corpus luteum degenerates and it turns into corpus albicans, stopping progesterone secretion. If fertilisation occurs and implantation also, the syncytiotrophoblast, the "root part" of the blastocyst (one of the early structures originated from the zygote), produces a hormone that is called <span>human chorionic gonadotropin (hCG). The hCG is what makes the corpus luteum keep secreting progesterone and maintain itself. The progesterone will then help keep the endometrium and, therefore, allow the development of the embryo to happen.</span>
Skeletal muscle fiber is a muscular tissue that is attached to the skeletal system. the skeletal muscle fibers are striated muscles i.e have striations in their structure. The skeletal muscle fibers are voluntary muscles i.e they can be controlled.
Motor unit is a composed of a motor nerve cell attached to a muscle fiber with its axon terminals. Motor nerve cells or neurons are the types of neurons that send impulses from the central nervous system to the responding organ. The muscle fiber may be attached to many neurons not only one neuron. Collectively, all the neurons attached to the same muscle fiber are called motor pool.
A skeletal muscle twitch is the contraction of a muscle fiber in response to the minimum stimulation.
The electrical stimulus is the stimulation of a skeletal muscle fiber by using external electrical impulses. The electrical stimulus is important in many sporting and medical situations.
A latent period is a period between applying a stimulus to a muscle fiber and the response of this muscle fiber by contraction.
<span>What motion will result from two forces acting on an object: one force of 50 newtons to the east, the other a force of 30 newtons to the west ? The object will accelerate to the east </span>
Answer:
With respect to the cases of early-onset Alzheimer’s disease are inherited, a type known as familiar Alzheimer’s disease (FAD), the statement is best supported by this information is that FAD is the result of a genetic change in one or more chromosomes.
Explanation:
Options for this question:
- <em>FAD is the result of a genetic change in one or more chromosomes.</em>
- <em>Natural selection will continue to reduce the incidence of FAD.</em>
- <em>FAD affects only the genes of middle-aged people.</em>
- <em>Deletion of one amino acid causes FAD.</em>
Alzhaimer's disease is a type of dementia that is characterized by neuronal degeneration, causing disorientation, memory and manual skills loss , among others. The familiar variety (FAD) is hereditary and is associated as a cause of disease and early Alzhaimer, before 60-65 years.
So far, three types of mutated genes related to FAD have been established:
- PSEN₁ or presenilin-1 gene
, more frecuent.
- APP or amyloid precursor protein gene.
- PSEN₂ or gene for presenilin-2, very rare or uncommon.
In some cases, people affected by FAD have alteration in more than one gene at the same time.
For this reason, it can be stated that FAD is the result of a genetic change in one or more genes or chromosomes.
Learn more:
Alzhaimer's disease brainly.com/question/7999310
