A stem-cell niche is an area of a tissue that provides a specific micro-environment, in which stem cells are present in an undifferentiated and self-renewable state.
The karyotype of a child born with Down syndrome includes a trisomy in chromosome number 21. The rest of the karyotype remains normal.
<h3>What is a karyotype?</h3>
A karyotype is a representation to indicate the chromosomes of a somatic cell in an individual.
In humans, somatic cells are diploids, thereby karyotypes will be formed by two sets of homo-logous chromosomes.
Down syndrome is caused by the presence of an additional chromosome number 21, and therefore the karyotype will exhibit three (trisomy) 21 chromosomes.
Learn more about karyotypes here:
brainly.com/question/1327739
Answer:
The answer should be the third explanation, which is "The experiment was subjected to both replication and repetition" because the question never provide information about the status of the scientists who conducted the experiment, the variables of the experiment, and whether or not a control group was included. The part where the question tells that many other scientists are doing the same experiments and obtaining similar results is the key to finding out the right answer,
Explanation:
For the answer to the question above, I believe the answer to the question is that <span>the steroid receptor protein cannot enter the nucleus so the gene of interest is repressed even in the presence of the hormone. I hope this helps</span>
