The answer is D, I just did the test
Answer:
Mitotic phase
Explanation:
The mitotic phase is a multistage process during which the duplicated chromosomes are aligned, separated, and moved to opposite poles of the cell, and then the cell is divided into two new identical daughter cells.
The first portion of the mitotic phase, mitosis, is composed of five stages which includes prophase, prometaphase, metaphase, anaphase, telophase , which accomplish nuclear division before reaching the second stage which is cytokinensis which involves the physical separation of the cytoplasmic componenets into two daughter cells.
The independent variable is the new plant food
Answer:
When a muscle cell contracts, the myosin heads each produce a single power stroke.
Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed into ADP and inorganic phosphate which is liberated. Myofilaments slide impulsed by chemical energy collected in myosin heads, <u>producing a power stroke</u>. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Answer:
Explanation: Trophic level, also called feeding level, is defined as the feeding level or each stage in a food chain or food web. In other words, trophic level is the number of links by which food energy is transferred from producers to final consumers. For example, in a food chain like the one below, we can have these levels.
