Through a sequence of steps called the immune response<span>, the </span>immune system<span>attacks these </span>pathogens<span>. ... This is the </span>immune system<span>. Cells. The cells involved are white blood cells (leukocytes), which seek out and destroy disease-causing organisms or substances</span>
Microscopes are one of the laboratory tools used to maximize the visual acuity of a certain specimen, it maybe a living or non-living organism or object. Thus, microscopes are widely used in these laboratories to increase microscopic observation with entities that cannot be perceived thru the naked eye. However, for scientisits to determine such specimen is a living thing if there's a presence of cell. Cell cannot be viewed via the visual organs alone but with the microscope a living specimen can be discerned with its characteristics such as cellular structure, slight and fidgety movement and other particular details..
Answer:
C) Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Explanation:
The pattern of gene expression wherein either paternal or maternal gene is expressed in specific cells while the other one is prevented from expression is known as genomic imprinting.
In the given example, the maternal copy of the gene on chromosome 15 is expressed in brain cells while its paternal copy is not expressed in these cells. Hence, the pattern of expression of this gene is regulated through genome imprinting. One of the mechanism is methylation of cytidine residues of CpG islands of the DNA that are more frequently present within promoters of the genes.
When the cytidine residues of these sequences are methylated into 5-methylcytidine, the transcription factors do not bind to these promoters preventing the expression of these genes.
Hence, methylation of cytidine residue in CpG islands of the promoters of the gene present on chromosome 15 could have silenced its expression in brain cells.
The tilt of the earth's axis, which essentially "turns" certain parts of earth so that some parts receive more direct sunlight
Answer: a. Blood and mucus in the stools.
Explanation:
Diarrhea is a gastrointestinal problem. It is associated with the symptoms of loose stools, cramps, vomiting, fatigue, and stomach pain. The diarrhea usually last for few days to week. It is also associated with the signs of dehydration due to loss of fluid through loose stools like stretchiness in skin, loss of color of skin, and fast heart rate. The diagnostics of diarrhea can be done by examining the blood and mucus in the stool.
