Answer:A. The release of calcium ions causes myosin and actin to attach to each other.
The contraction of skeletal muscles takes place by induction of a nerve impulse, which produces a movement and the interaction of the filaments containing proteins named as actin and myosin. This interaction of filaments is regulated by proteins called tropomyosin and troponin present on the actin filaments. The motor nerve causes the depolarization of the muscle membrane sarcolemma. This triggers the sarcoplasmic reticulum to release calcium ions. This calcium binds to troponin and thus allows the tropomyosine strand on the actin filament to displace so that the part of the actin where myosine head needs to be attached remain uncovered. Binding of the actin myosine filament results in contraction.
Hence, the release of calcium ions causes myosin and actin to attach to each other causes muscle contraction.
Answer:
PpDD and PpDd
Explanation:
Pigmented eyes (P) are dominant to non-pigmented (p), and dimpled chins (D) are dominant to Non-dimpled chins (d).
The <u>possible genotypes of a pigment-eyed, dimple-chinned person</u> would be PPDD, PpDd, PPDd, PpDD while a blue-eyed person without a dimpled chin would have the genotype ppdd.
The genotype of a blue-eyed, dimpled chin child would be either of ppDd or ppDD, but in this case, the mother is ppdd and as such, the child cannot have two copies of D allele. Hence, the genotype of the child can only be ppDd.
In order for the child to have blue eyes (pp), it means that the father has to have the non-pigmented allele (p). This also means that the father is heterozygous for eye pigmentation (Pp).
<em>Hence, the genotype of the father is now limited to </em><em>PpDD</em> <em>and </em><em>PpDd</em>.
It could trigger nuclear fussion
What? im aorry i dont understanf
