Answer:
The correct answer is 3: "<em>High levels of Ca2+ are expected to be found </em><em>within the sarcoplasmic reticulum</em>".
Explanation:
Muscular contraction is a highly regulated process that depends on free calcium concentration in the cytoplasm. Amounts of cytoplasmic calcium are regulated by <u>sarcoplasmic reticulum</u> that functions as a storage of the ion.
When a nerve impulse reaches the membrane of a muscle fiber, through acetylcholine release, the membrane depolarizes producing the entrance of calcium from <u>extracellular space</u>. The impulse is transmitted along the membrane to the sarcoplasmic reticulum, from where calcium is released. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. The calcium channel in the sarcoplasmic reticulum controls the ion release, that activates and regulates muscle contraction, by increasing its cytoplasmic levels. When <em>calcium binds to the troponin C</em>, <em>the troponin T alters the tropomyosin by moving it and then unblocks the binding sites,</em> making possible the formation of <em>cross-bridges between actin and myosin filaments.</em> When myosin binds to the uncovered actin-binding sites, ATP is transformed into ADP and inorganic phosphate.
Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Answer:
C.
Explanation:
Asexual reproduction produces identical copies of the parent. While sexual reproduction produces a mix of two parents DNA and features.
Answer:
Hello! There are numerous things that support Darwin's theory of evolution, but the most credible ones include:
*Homologous structures - structures that are similar in structure but different in function (e.g. wing of a bat and arm of a human).
*Embryology - the study of embryos
*Continental drift - some fossils of organisms that were adapted to a different environment are often found in different climates/areas they don't seem to have been adapted to.
*DNA - similarities in the genomes of certain animals are often used to compare amino acid sequences and protein production.
I hope I helped!
There are a bunch more, but I decided to leave a select few for you to write about.
Feel free to leave a comment down below if you need more assistance. :)
Runoff describes water movement and infiltration describes water storage.
Answer:
Associative learning may be defined as a type of learning in which the new response gets easily associated with the stimulus. Except habituation learning all simple learning procedure are included in this learning.
In the associative learning, reactions of an individual are based on there spank. George learns to cry on being spanked this is because this stimulus of sister cries gives response. Crying do not show any effect on ken because he does not know about his sister crying.
