The cardiac muscle has intercalated disk that allows rapid transmission of the impulse. This will allow the cardiac muscle to have a coordinated way. The heart muscle has pacemaker that will spread the signal in regular time. The transmission of impulse is also controlled by a few checkpoint like the bundle of his to make the signal to the Purkinje fiber of left and right ventricle at the same time.
Answer:
The correct answer will be option-
1. UV light strikes the skin and converts a steroid molecule into an inactive form of vitamin D.
2. Inactive vitamin D is transported to the liver where it is modified.
3. Vitamin D is activated under the influence of PTH.
4. Inactive, chemically altered vitamin D is transported to the kidneys.
Explanation:
Vitamin D is a fat-soluble metabolite which helps maintain the health of the bone by maintaining the calcium homeostasis.
The vitamin D is synthesized mainly in the liver and kidney from the biologically inactive precursor of vitamin D called ergocalciferol and Cholecalciferol.
The inactive vitamin is synthesized in the skin when the skin is exposed to UV rays. The UV rays convert the 7-dehydrocholesterol, a steroid molecule to Vitamin D3, This inactive vitamin is then transported to the liver where it is converted to 25-hydroxyvitamin D.
This vitamin D form is further metabolized in the kidney controlled and regulated by the Parathyroid glands.
In the lyric cycle, the virus attaches to the host cell which then injects its DNA. By using the hosts cellular metabolism
Answer:
it would be at the bottom of the hill. That's where all of the energy from the descent is at its peak.
Answer:
a. to treat a disease characterized by a gene that is not expressed.
Explanation:
The RNA interference (RNAi) technique is widely used in molecular biology to inhibit target gene expression at the post-transcriptional level. The RNAi technology uses small interfering RNAs (siRNAs) consisting of 18-22 nucleotides that bind to complementary acid nucleics (i.e., DNA and RNA), thereby inhibiting target gene expression. Recently, it has interestingly been discovered that small RNA sequences targeting promoter regions can also be used to activate the expression of endogenous target genes through a mechanism called RNA activation (RNAa).