Answer:
The sarcoplasmic reticulum contain calcium ions in skeletal muscles which is involved in muscle contraction.
Explanation:
Sarcoplasmic reticulum is an intracellular system of closed saclike membranes involved in the storage of calcium in skeletal muscle cells. The sarcoplasmic reticulum regulates the concentration of calcium and determine muscle contraction.
Answer:
Inappropriate activation of telomerase can result in cellular immortality, one of the cellular changes implicated in the development of cancer.
Explanation:
Some studies show that when telomerase activity is stimulated and a tumor suppressor gene (the p16INK4a gene) is inactivated, cellular immortalization occurs, which constitutes an important step towards the formation of a tumor.
The fifth week of pregnancy is considered part of the embryonic stage of prenatal development.
During this stage, the embryo continues to grow in size, the placenta and the amniotic fluid begins to form, and the mother experiences several hormonal changes as a response to the embryo's implantation into the uterus of the mother.
The embryo's cells begin forming specialized functions in a process called differentiation. The baby's heart, spinal cord, and brain begin to develop, so as his/her blood cells, kidney cells, and nerve cells. His/her external physical features also begin to form.
The embryonic stage ends at the end of the 10th or the beginning of the 11th week of pregnancy, where the developing baby is now called a fetus.
... termed "hypotonic," meaning less solids (or more diluted) than inside the cell. For fluid movement in/out of cells, water will diffuse (via osmosis) from the hypotonic solution to the hypertonic one, assuming a permeable barrier (i.e. cell membrane) allows it. With this case, water will flow into the cell from outside.
Answer:
Genetic variation
Explanation:
It could lead to natural selection, but natural selection isn't the cause. Many years down the road you could see a particular variation having a higher population, which is the result of natural selection/survival of the fittest via better camouflaging from predators.
