Human Reproduction Test 4

In the female genital tract, some lipid is removed from the sperm surface to make it active or allow easy removal of enzyme.

Capacitation occur in Vagina to remove lipid from surface of sperm to make active.

The sperm contacts the egg cell at zona pellucida. The zona pellucida then undergoes chemical changes which renders egg insusceptible to further encounters with another sperm. This is essential to ensure that only a single sperm fertilizes the egg.

The haploid ovum is formed after the second round of meiosis is completed. This haploid ovum is also called as ootid. Oogonium is the egg mother cell that is diploid and undergoes meiosis to form egg.

Cortical granule release from ovum due to penetration of one sperm which is responsible for preventing polyspermy.

Acrosome of Sperm have enzyme for Sperm wall digestion.

Fertilization occurs in Ampulla region of fallopian tube.

Sperms are released into the vagina. From here, they travel through the cervix and uterus before reaching oviduct or fallopian tube, where they can encounter an egg.

Total no. of meiosis II is equal to total no. of fertilization.

Second polar body is result of meiosis II occur after fertilization so least in number.

The menstrual phase is the first phase of the menstrual cycle. This is the part of the cycle when a person has their period.

The cycle starts when the egg from the previous menstrual cycle does not become fertilized. Hormone levels of estrogen and progesterone drop.

Because the thickened uterine lining is not needed, it will break down and shed. This lining and the egg then exit through the vagina during the menstrual period.

Fertilization occurs only when the egg and sperm are present in the ampulla at the same time. Hence the coitus should happen near the period of ovulation. Ovulation occurs at the end of the follicular phase or the onset of luteal phase.

Polyspermy is prevented by Depolarization of membrane due to entry of sperm lead to influx of Ca and then cortical granules release to form fertilization membrane.

• Fertilizin is present on the outermost layer of the ovum or the egg of the female gamete.
• Fertilizin is made up of glycoproteins or say mucopolysaccharide and is present as a chemical sheet on the egg.

Antifertilizin is located on sperm head which promote Fertilizin and antifertilizin reaction between sperm and ovum.

• Egg (ovum) secretes a chemical named fertilizin (composed of glycoprotein = monosaccharides + amino acids) and sperm has on its surface a protein substance called antifertilizin (composed of acidic amino acids).
• The fertilizing of an egg interacts with the antifertilizin of a sperm of the same species and responsible for Agglutination.

• A fertilizin is a proteoglycan secreted from the cortical region of the egg cytoplasm, that interacts with the antifertilizin of the sperm of the same species. This makes the sperms stick to the surface of the egg.
• An antifertilizin is a protein present in the plasma membrane of the sperm. 
• Fertilizin acts as a receptor for antifertilizin and the reaction between fertilizin and antifertilizin makes the sperm more capable of fertilizing the egg of the same species. 

Amphibian produce unfertilized eggs in outer environment.

Fertilization is defined as a process of fusion of male and female gametes. The gametes are special haploid cells. The most widely accepted definition of species is the biological species- according to which members of same species alone can carry on the process of sexual reproduction (including fertilization) and produce fertile offspring.

The fertilization of the ovum with only one sperm is termed as monospermy causes the fertilization membrane to prevent the entry of other sperm. So, the correct answer is, 'Formation of fertilization membrane. '.

• Ectopic pregnancy occur in region other than uterus.
• An ectopic pregnancy occurs when a fertilized egg implants and grows outside the main cavity of the uterus. 
• Most ectopic pregnancies (90%) occur in the fallopian tube, which are known as tubal pregnancies, but implantation can also occur on the cervix, ovaries, cesarean scar, or within the abdomen.