Answer:
True
Explanation:
Tobacco is consumed during smoking which contains an addictive substance called Nicotine. Nicotine exerts its effect on the body by stimulating the acetylcholine receptors in the neurons. The stimulation of these receptors stimulates another neurotransmitter like glutamate, dopamine and GABA which produce addictive effects in humans.
Since the acetylcholine is involved in stimulating the other neurotransmitters therefore true is the correct answer.
Thus, true is the correct answer.
The correct answer is d: cDNA.
<span>cDNA or complementary DNA is DNA synthesized usually from messenger RNA (mRNA) by the enzyme reverse transcriptase. Because this molecule is from mRNA it contains only exons. cDNA is also produced naturally by retroviruses, for example, HIV virus.</span>
Answer: An abiotic factor is a non-living factor that influences and resides in an environment. So, things like weather, temperature, and humidity are considered abiotic factors, while things like predators are considered biotic factors.
Explanation:
Answer:
is a form of RNA processing in which newly made precuesor messanger
splicing takes place within the nucleus
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
