Twins absolutely resembling each other in sex and external appearance ...
Twins absolutely resembling each other in sex and external appearance are referred to as Identical Twins. Identical twins are formed when one egg after being fertilized by one sperm, divides into two halves. The two halves are genetically identical and of the same sex. Because these twins come from one zygote, they are also known as monozygotic.
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Twins absolutely resembling each other in sex and external appearance ...
Twins absolutely resembling each other in sex and external appearance this happen only when egg and sperm have same genetic make up thus option c is correct
Twins absolutely resembling each other in sex and external appearance ...
Explanation:
When we talk about twins, there are two types: identical twins (monozygotic) and fraternal twins (dizygotic). Identical twins occur when a single fertilized egg splits into two separate embryos, while fraternal twins occur when two separate eggs are fertilized by two separate sperm.
Identical twins:
Identical twins occur when two halves of the same egg develop separately after it is fertilized by one sperm. This happens during the early stages of embryonic development. Here's a detailed explanation of how it occurs:
1. Fertilization: A sperm cell fertilizes an egg cell, resulting in a single fertilized egg or zygote.
2. Splitting into two embryos: After fertilization, the zygote starts to divide and develop into an embryo. In the case of identical twins, the zygote divides into two separate embryos during the early stages of development.
3. Separate development: Each of the two embryos continues to develop independently, resulting in two separate individuals. Since they originated from the same fertilized egg, the twins will have the same genetic material and, consequently, a high degree of resemblance in terms of sex and external appearance.
Key Points:
- Identical twins result from the splitting of a single fertilized egg into two separate embryos.
- The splitting occurs during the early stages of embryonic development.
- Each embryo develops independently, resulting in two individuals with the same genetic material.
It's important to note that the other options mentioned in the question do not lead to identical twins:
Option A: Two similar sperms fertilizing two similar eggs would result in fraternal twins, as each embryo would have a different genetic makeup.
Option B: If the same sperm fertilizes two eggs, it would result in fraternal twins, as each egg would have a different genetic makeup.
Option D: If two halves of the same egg are fertilized by two separate sperms, it would result in fraternal twins, as each sperm would have a different genetic makeup.
Therefore, the correct answer is option C: Two halves of the same egg develop separately after it is fertilized by one sperm, resulting in identical twins who resemble each other in sex and external appearance.
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