Answer:
a
Explanation:
its a limitation not a bost have a good day
Answer:
9:3:3:1
Explanation:
If alleles of two genes separate randomly during anaphase-I of meiosis, some new combinations of the alleles are formed in the gametes. A heterozygous genotype for two loci (let's support TtRr) produces a total of four types of gametes in 1:1:1:1 ratio (TR, Tr, tR, and tr). The random fusion of these gametes from two double heterozygous parents (TtRr x TtRr) gives a phenotype ratio of 9:3:3:1. Here, 9/16 F2 progeny exhibit dominant phenotype for both loci while 1/16 exhibits recessive phenotype for both the genes. Rest 3/16 and 3/16 F2 progeny express dominant trait for one gene and recessive for the other.
When it's hot or when the organism starts sweating a lot, this causes an amount of water to be lost from the body. Water is important for the organism to survive and it's absence wi lead to death, therefore Osmoreceptors cells in the hypothalamus in the brain, sends signals to increase the rate of water re-absorption by the kidney. This causes the urine to be of a low volume and more concentrated. This allows enough water to be used by the body as a lot has been lost during sweating.
Answer: 2. Precipitation
Explanation:
Aerobic cellular respiration requores oxygen. Photosynthesis does, as well.
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