The changes in which layer or membrane of ovum check the entry of additional (more than one) sperms?
The zona pellucida layer of the ovum shows certain changes after the penetration of sperm and thus checks the entry of additional sperms.
Sperm transfer in males can be prevented by blocking the:
The sperm produced in testis and travel through Vas deferns to come out through urethra, so we block vas deferns to prevent the flow of sperm.
What is the average time interval for the repetition of menstrual cycle in females?
After every 28-30 days a mature ovum is released by ovary and wait for sperm to get fertilized. In case the fertilization does not takes place the uterine wall breaks and ovum comes out of vagina as blood. It is known as menstruation.
Which of the following connects placenta to embryo?
The fetus is connected to the placenta through the umbilical cord, a tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries, exchange gases and other substances with the mother's blood, and travels back to the fetus through the umbilical vein.
After a period of weeks, the development of almost all major organs of an embryo has occurred.
Correct Answer :- c
Explanation : Almost all organs are completely formed by about 10 weeks after fertilization (which equals 12 weeks of pregnancy). The exceptions are the brain and spinal cord, which continue to form and develop throughout pregnancy. Most malformations (birth defects) occur during the period when organs are forming.