The chemical that caused decline of the eagle population is pesticide DDT
The answer is; A & C
The lagging strand is replicated in fragments called Okazaki fragments, each initiated by a primer. The fragments are later joined into one strand by DNA ligase. Replication occurs by adding nucleotides to the 3’ end of a preceding nucleotide. Because the lagging strand is antiparallel to the leading strand, the replication of the lagging strand is in the opposite direction as the replication fork direction. This is why the lagging strand is replicated in fragments because replication is being carried out by a single DNA polymerase (moving in the direction of the replication fork) per replication fork.
the broken rock layers of mostly solid rock is true
Answer:
The prolonged electrical depolarization of cardiac muscle cells -that occurs during contraction- is due primarily to the persistent influx of calcium ion
Explanation:
The action potential of the heart muscle is longer with respect to skeletal muscle (around 300 milliseconds), and this is due to the activity of calcium (Ca⁺⁺ ) in the intracellular compartment.
The initial depolarization of cardiac muscle fiber depends on the entry of sodium (Na⁺) into the cell. However, for the action potential to occur and be maintained, Ca⁺⁺ must increase its cytoplasmic levels, which depends on:
- The increase in intracellular sodium induces the release of Ca⁺⁺ from the sarcoplasmic reticulum.
- Calcium entry from the extracellular space through the voltage dependent Ca⁺⁺ channels.
- The entry of extracellular Ca⁺⁺ causes the release of more Ca⁺⁺ ions by the sarcoplasmic reticulum, further increasing its intracellular concentration.
This is how the ion that guarantees the duration of the action potential of the cardiac muscle cell is the Ca⁺⁺.
Learn more:
Calcium, sodium and cardiac muscle cells brainly.com/question/4473795
The oxygen molecules moves through the nostrils, pharynx, trachea, bronchus, smaller and smaller branches of the bronchial tree, and then into the alveolus.
