<span>Antibiotics work by selectively targeting the reproduction or growth of specific bacteria cells and by not attacking human DNA. Antibiotics do not, or should not, target and affect human DNA gyrases, although they should target the specific bacteria growth. The host, (human) DNA needs to remain unharmed while the bacteria does not replicate.</span>
Answer:
Power stroke (myosin head bends) coupled with the release of ADP and phosphate
Explanation:
Muscle contraction results from myosin heads adhering to actin and attracting it inwards. It uses ATP. Myosin adhers to actin at a binding site of its globular actin protein and adheres at another binding site for ATP (hydrolyzed ATP to ADP, Pi and energy)
ATP binding prompts myosin to detach from actin, ATP is changed to ADP and inorganic phosphate, Pi by ATPase. The energy formed at this process orientates myosin head to a “cocked” direction.
The myosin head goes in the direction of the M line, holding the actin with it in the process causing the filaments to orientate nearly 10 nm in the direction of the M line--- power stroke (force is produced), the sarcomere reduces in length and the muscle contracts.
Note: The power stroke is seen when ADP and phosphate disattaches itself from the myosin head.
At the terminal point of the power stroke, the myosin head as low-energy, followed by ADP release.
The attached image shows the cross-bridge muscle contraction cycle, which is activated by Ca2+ sticking to the actin active site. And how actin moves in relation to myosin.
Mutations are the source of all new alleles. An allele is a variant form of a gene. Variations in alleles lead to variations in organisms. Positive mutations give an organism a better chance of survival. It means that the mutation may be passed on to the offspring. Negative mutations may lead to an early death.<span> Therefore, changes in alleles from one generation to another form the basis of evolution.</span>
Answer:
The superior temporal gyrus (STG) is on the inferior–lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the “parabelt,” which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas.
Explanation:
Auditory cortex has been less extensively studied in primates than visual cortex, and little is known about auditory cortex organization in galagos. The standard model for the early stages of processing in auditory cortex of primates now includes a core of three primary or primary-like areas, A1 (the primary area), R (the rostral area), and RT (the rostrotemporal area), surrounded by a belt of eight secondary areas, bordered laterally by a parabelt, a third level of cortical processing of two divisions