In humans, genetic variations are caused because humans reproduce by a sexual life cycle which is termed as meiosis. In such a life cycle, the offspring receives half the chromosomes from the mother and half from the father. Crossing over and random assortment of chromosomes are two phenomenons which occur during meiosis. Due to these two phenomenons, genetic variations are caused.
During crossing over, the exchange of DNA segments between the homologous chromosomes takes place which brings about the genetic variations.
Doctors would let your body's immune system fight off a bacterial infection. If the infection gets worse, then the doctors would proscribe you with some antibiotics so it'll fight off the harmful bacteria.
This is True . the reabsorption through the proximal tubule is obligatory 80% whereas water reabsorption through distal tubule is facultative but mostly through collector tubules 15 % ( under the action of aldosteron and antidiuretic hormone).
