Scientists have sequenced the whole human genome; this means that the normal DNA sequence for the whole of human body is known. Thus, it is now possible to known the specific abnormalities that occur in disease conditions.
This means that people that are at risk of certain diseases can be tested by taking DNA sample from them and then comparing the sequence of their DNA with that of the diseased DNA sequence.
For instance, pregnant women that are at risk of giving birth to children with down syndrome can be tested in the hospital to find out if the baby inside them have the disorder. This is done by collecting some amniotic fluid from their body, the fluid is then analyse for DNA sequence. If the fetus has down syndrome the pregnancy will be aborted.<span />
Answer:
it has the ability to turn off genes
Answer:
The answer to this question is given below in this explanation section.
Explanation:
"advantages of interconnecting air sacs for birds"
The air sacs permit a unidirectional flow of air through the lungs.Unidirectional flow means that air moving through birds lungs is largely fresh air and has a higher oxygen content.In contrast air flow is bidirectional in mammals moving back and forth into and out of the lungs.As a result air coming into a mammals lung is mixed with old air has less oxygen. so in bird lungs,more oxygen is available to diffuse into the blood(avian respiratory system).
- The air sacs are thin membrane structures connected to the primary or secondary bronchi via ostia and they comprise most of the volume of the respiratory system.
- Air sacs are poorly vascularized by the systemic circulation and do not directly participate in significant gas exchange but act as a bellows to ventilate the lungs.In most species,there are nine air sacs which can be considered in cranial and caudal functional groups.
- The cranial group consists of the paired cervical air sacs,the unpaired clavicular air sacs and the paired cranial thoracic air sacs.
It depends on the cell type. If it's a tissue cell, it will divide into 2 daughter cells through the mitosis process. If it's a gamete cell, it will divide through meiosis into 4 daughter cells.
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