Oogenesis
The formation of the ovum (mature female gamete) from undifferentiated germ cells is called oogenesis. This process takes place in the ovaries (female gonads). Oogenesis consists of three stages known as the multiplication phase, growth phase, and maturation phase.
Cell Division
Cell division involves the formation of new daughter cells from the parent cells. It is a part of the cell cycle that takes place in both prokaryotic and eukaryotic organisms. Cell division is required for three main reasons:
Spherocytosis is an inherited blood disease in which erythrocytes (red blood cells) are spherical instead of biconcave. This condition is inherited in a dominant fashion, with ANK1 (the nonfunctional mutant allele) dominant to ANK1+. In people with spherocytosis, the spleen recognizes the spherical red blood cells as defective and removes them from the bloodstream, leading to anemia; this removal occurs with different efficiency in different people.
Some people with spherical erythrocytes suffer severe anemia, some have mild anemia, and others do not have any symptoms of anemia.
When 2400 people with the genotype ANK1/ANK1+ were examined, it was found that all of them had spherical erythrocytes, 2250 had anemia of varying severity, and 150 had no anemia symptoms. The ANK1/ANK1 genotype is never observed.
Which evidence suggests that spherocytosis is incompletely penetrant?
Step by step
Solved in 3 steps
