The connective tissues of mammalian brain is called the meninges. There are three layers of this tissue. The outer layer is called the dura mater. The arachnoid is the middle layer and the pia mater is the inner layer of it.
At the end of meiosis, there are FOUR cells with HALF the amount of DNA.
Meiosis is a kind of cell division that produces genetically different daughter cells. Unlike mitosis, which produces genetically identical cells, meiosis goes through 2 divisions that leads to 4 daughter cells.
In meiosis, the parent cell first duplicates all its genetic material, just like what they do in mitosis. Then it divides, leading 2 genetically identical daughter cells. Mitosis ends here, but in meiosis, the 2 cells divides themselves again, but without duplicating their DNA. This leads to the 4 daughter cells with only half of the number of chromosomes.
We call these cells haploid. They're usually common in gametes. For example, a normal body cell in human has 46 chromosome, but in the cells after meiosis, they only have 23.
Nicotine and cigarette smoke extract show acute physiological effects on lungs.
Explanation:
Cigarette smoke contains many chemicals that interfere with the body's method of filtering air and cleaning out the lungs. The smoke irritates the lungs and leads to overproduction of mucus. It also paralyses the cilia which results in accumulation of toxins and mucus, resulting in congestion of the lungs.
Tobacco smoke increases tracheal pressure, pulmonary artery pressure, systemic blood pressure and left atrium pressure. It decreases cardiac output and blood flow to the left lower lobe. It induces bronchoconstriction thus decreases peak flow in healthy subjects. It is also known to cause temporary slowing of mucociliary clearance of the lungs.
D I believe, that sounds about right
about 30% of earth's freshwater is groundwater.