Describe the stages of pre-embryonic development in humans.
- PRE-EMBRYONIC DEVELOPMENT -The prenatal development can be divided into two phases, embryonic and foetal. The embryonic phase of development is said to
really start from the second week after fertilization; and subsequently lasts up to 8
weeks of the 1st trimester. In this section we describe the pre-embryo stage starting
with the events that take place at fertilization and then proceed to describe the development of the pre-embryo up to two weeks of development.
Fertilization - Ovulation usually takes place between 9th to 14th day after the end of last menstrual period. Fertilization of oocyte initiates development and should occur within about 24 hours after ovulation; otherwise the oocyte degenerates. The female reproductive tract plays a very active role in the fertilization process. Newly ejaculated mammalian sperms are unable to undergo acrosomal reaction unless they reside in the female
reproductive tract for some time. This requirement is known as capacitation. During this process the sperm membrane
____ ________ ________ ___ ___.
__________ ___ _________ _____ _______ _____ ____ _________ ______.
_______ __________ _________ ___ __________ ___ __________ _________.
_________ ___ ____ _______ _______ _______ ___ ___ ___.
____ ____ _________ ___ ________.
_____ ______ ____ ________ _____ _________ _________ ______ ________ __________.
____ _______ ____ __________ _________ ______ ___ _______.
______ ____ _________ _________ ______ _________ _____.
____ ___ _________ _____ _________ _______ _______ ___ ____ ________.
____ ___ ________ _________ ________ _______ _____ _______.
_________ __________ ___ _______ _____ __________ ________.
_______ ___ __________ _____ ______ ___ ________ _________.
________ __________ ____ __________ ______ _________ ____ __________.
__________ _______ __________ ____ ____ ______ ______ ___ ______.
_____ ____ _____ _____ ___.
_____ ________ ___ ____ __________ ________ _____ ___ ______ _________ __________.
______ _________ _________ ____ ____ _______ _____ _______ _____.
________ _________ _________ ___ _____ ___ _______ __________ __________ ________ _______ _____.
____ _______ ____ _____ __________ __________ _________ ___.
_______ ______ ______ _________ ______ _______.
_________ _________ _____ _______ _________ _____ ______.
____ ________ _________ ____ ____ _______ __________.
_____ __________ ___ ______ _______.
____ _________ ____ _________ _______ _________.
_______ ___ ____ _____ ___ ____ ______ _________ ___ ____ _______ ___.
_________ _________ ______ ______ ________ ________ _____ _______ __________ ____ ___.
___ ______ __________ ___ _______.
___ ______ __________ _______ _______ _______ ________ _______ ______.
_____ ___ ____ __________ _____ ________.
_______ _________ ________ __________ ________ ________ ____ ___ ___ ________ ____ ___.
___ ______ ______ __________ ________ ____ ________ _____ _________ ________.
_______ ______ ________ ________ _____ _________ ____ _______ _________ __________.
____ ______ ________ ____ _____ ______ ___ _________.
_____ _________ ________ _______ __________ _______ __________ __________ ______ __________ __________ _____.
_________ ___ _________ __________ _______.
_______ ___ __________ ______ _____ _____ _________ _______ __________ ______ ________.
__________ ___ ____ ____ _________.
___ ___ ________ _____ ______ ________ ______ __________ ___ ___ _________.
_________ _________ ______ _________ _____ _____ ____ _________ ___ _________ __________ ___.
________ __________ _____ _____ ____.
_____ ______ ___ _____ _________ _____ _______ _________ ___.
___ _______ ___ __________ ___ _____ ________.
________ ______ ______ ___ ________ ________.
____ _____ __________ __________ ___ ________ _____ ________ ___.
_____ _____ _________ __________ _______ __________.
______ __________ ________ _____ _________.
_________ _________ _________ ______ ___ __________.
______ _____ ___ _______ ________ ___.
__________ _____ _______ _________ _____ _________.
_________ __________ ________ _______ _______ _________ _________ _______ ________.
________ _______ ____ ______ ___ ________ ________ _______ ___ ______ _______.
________ _____ _________ ______ _____ __________ _________.
_____ ______ _____ ___ ____.
_________ _______ _______ ______ _______.
____ ________ ________ ____ ___ ________ __________ _____ _____ _______ _______.
___ _______ _____ ___ ____ ____ _____ ______ __________ _______.
_____ _____ ___ _________ ________ ______ _________ ________ _______ ___.
_____ __________ _____ __________ ______ ___ ________ ___ ____.
______ ____ __________ _________ _____ _________ ______ _____ _________.
_______ __________ ______ _________.
- Solved Assignments
- Study Notes
- Guess Papers
- Question Papers
✓ Unlock up to 60% of the answer
✓ No payment required