EMBRYOLOGY
FERTILISATION EARLY DEVELOPMENT OF EMBRYO AND IMPLANTATION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
one ovum is fertilized by two sperms
|
|
|
two ova are fertilized by two sperms
|
|
|
two ova are fertilized by one sperm
|
|
|
one ovum is fertilized by one sperm and does not separate completely
|
Detailed explanation-1: -This occurs because the fertilised egg divides in two while it is still a tiny collection of cells. The self-contained halves then develop into two babies, with exactly the same genetic information. Twins conceived from one egg and one sperm are called identical or ‘monozygotic’ (one-cell) twins.
Detailed explanation-2: -Identical twins are produced from a single fertilized egg that splits into two at an early stage of cell division. It is produced from a single ovum fertilized by a single sperm. Identical twins are of the same sex.
Detailed explanation-3: -Because fraternal, or dizygotic, twins are 2 separate fertilized eggs, they usually develop 2 separate amniotic sacs, placentas, and supporting structures.
Detailed explanation-4: -Conjoined twins develop when an early embryo only partially separates to form two individuals. Although two babies develop from this embryo, they remain physically connected-most often at the chest, abdomen or pelvis. Conjoined twins may also share one or more internal body organs.