Question

explain the steps in the formation of an ovum from an oogonium in humans

Answer 1

The steps in the formation of an ovum from an oogonium in humans involves in oogenesis process. It can be divided into three stages :
(a) Multiplication phase (b) Growth phase
(c) Maturation phase
(a) Multiplication phase : In this stage primordial germ cells or ovum mother cells are repeatedly divided by mitosis to form large number of diploid oogonia. This process completes in embryo stage of female in most higher animals.
(b) Growth phase : In this process oogonia grow in size and form primary oocytes. The growth phase is the longest phase oogenesis (except humans). During growth phase size of egg increases many times.
(c) Maturation phase : Oogenesis takes place in the ovaries. In contrast to males the initial steps in egg production occur prior to birth. By the time the foetus is 25 weeks old, all the oogonia that she will ever produce, are already formed by mitosis. Hundreds of these diploid cells develop into primary oocytes, begin the first steps of the first meiotic division, proceed up to diakinesis, and then stop any further development. The oocytes grows much larger and complete the meiosis I, forming a large secondary oocyte and a small polar body that receives very little amount of cytoplasm but one full set of chromosomes.


Hope it helps

Answer 2

Here is a chart to explain the steps in the formation of an ovum from an oogonium in humans with description in another page. This might help u!!