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⁺⁺.
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Calcium, sodium and cardiac muscle cells brainly.com/question/4473795
It happens during the s phase
Answer:
The answer to this question is given below in this explanation section.
Explanation:
"Alternation of generation"
Alternation of generations is the type of life cycle that occurs in those plant and algae in the archaeologist and the heterokontophyta that have distinct haploid sexual and diploid asexual stages.In these groups a multicellular haploid gametophyte with n chromosomes alternates with a multicellular diploid sporophyte with 2n chromosomes made up of n pairs.A mature sporophyte produces haploid spores by meiosis a process which reduces the number of chromosomes to half from 2n to n.
Two haploid spores germinate and grow into a haploid gametophyte.At maturity ,the gametophyte produces gametes by mitosis which does not alter the number of chromosomes.Two gametes from different organism of the same species fuse to diploid zygote,which develop into a diploid sporophyte . This cycle from gametophyte to sporophyte in the way in which all land plant and many algae undergo sexual reproduction.
Answer:
7.false 8.commensalism 9.last one
Explanation:
