Whether it is brand-new or years old, a mattress too soft for your comfort level may make for many restless nights. As long as the mattress is in good shape, there's no need to replace it to achieve the desired level of firmness.Instead, purchase a firm topper, slide a bed board beneath the mattress, or add extra support to the bed frame itself. sheet of plywood cut to the same size as the mattress offers support for a mattress that has lost some of its firmness. Slide the plywood between the mattress and box spring.
Human cells normally contain 23 pairs of chromosomes, for a total of 46 chromosomes in each cell (illustration). A change in the number of chromosomes can cause problems with growth, development, and function of the bodyâs systems.
Sperm and eggs are sex cells. Meiosis is the start of the process of how a baby grows. Normally, meiosis causes each parent to give 23 chromosomes to a pregnancy. When a sperm fertilizes an egg, the union leads to a baby with 46 chromosomes. But if meiosis doesnât happen normally, a baby may have an extra chromosome (trisomy), or have a missing chromosome (monosomy).