Answer:
The valves' main job is to keep the blood moving in one direction – back up towards the heart. When the valve is open, blood freely flows upward towards the heart and when the valves are closed, blood cannot flow back
I think it's first quater, hope that helped!
Answer:
Description
An electron cloud is the region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital. It is defined mathematically, describing a region with a high probability of containing electrons.
Answer:
The amplitude of a wave is the height of a wave as measured from the highest point on the wave (peak or crest) to the lowest point on the wave (trough). Wavelength refers to the length of a wave from one peak to the next.
Explanation:
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