Question

Which of the following will result in MALE infertility in sea urchins? Select one: a. A mutation that affects the hydrolitic enzymes inside the cortical granules b. A mutation that prevents the acrosome reaction to occur C. A mutation that changes the three-dimensional shape of the bindin receptor on the sperm membrane d. More than one option can cause MALE infertility in sea urchins e. A mutation prevents the 9+2 arrangement of the actin microfilaments that give structure to the sperm tail

Answer 1

1. Hydrolytic enzymes and present in the acrosomal cap. These enzymes are needed to digest the zona pellucida to enter into the Oocyte. If the hydrolytic enzymes are defective then the sperm is not able to penetrate the zona pellucida. It leads to infertility.
2. Acrosomal reaction is a very necessary reaction in which the sperm plasma membrane fuses with the outer acrosomal membrane. The sperm with acrosomal membrane bound to the zona proteins. If acrosomal reaction does not occur, then the sperm will not be able to bind to the zona proteins to enter into the Oocyte. It leads to infertility.
3. As stated above, bindin receptor is needed to bind to the zona proteins. If this is defective,then the sperm membrane cannot bind to the zona proteins to enter into the Oocyte. It leads to infertility.
4. The sperm tail contains axonemal complex which is essential for sperm motility. It is a microtubular structure which provides skeleton to the sperm. It leads to infertility.

Answer is all options are correct. Option d.