Question

Why do human monosomics most often fail to survive prenatal development?

Short answer

Answer: Human monosomics often have severe consequences on prenatal development, as the loss of a chromosome leads to a deficiency in essential genes and proteins. These deficiencies disrupt normal cellular function and the formation of tissues and organs, ultimately making it difficult for the individual to develop properly and survive. In most cases, monosomic individuals fail to survive prenatal development, although some, like those with Turner Syndrome, may survive into adulthood with various health issues and developmental challenges.

Step-by-step solution

Definition of Human Monosomics

Monosomics refers to the condition where an individual has a missing chromosome from one of their pairs, resulting in an odd number of chromosomes. In humans, this typically means having 45 chromosomes instead of the normal 46.

Importance of Chromosome Number

Each chromosome carries specific genes that encode for proteins, which are essential for normal cellular function and development. When a chromosome is missing, it results in a loss of these essential genes and their corresponding proteins, often causing severe effects on an individual's growth and development.

Effects of Monosomics on Prenatal Development

During prenatal development, the cells are rapidly dividing and differentiating into specialized cell types that will form tissues and organs. In monosomic individuals, the loss of a chromosome and its corresponding genes may lead to improper cellular function, incorrect formation of tissues and organs, and overall disruption of normal development.

Turner Syndrome as an Example

Turner Syndrome is an example of human monosomics, where affected individuals are missing one of their X chromosomes (resulting in a total of 45 chromosomes). While most cases of monosomics result in early miscarriage, some individuals with Turner Syndrome can survive into adulthood, though they may face various health issues and developmental challenges due to the absence of specific genes from the missing chromosome.

In Conclusion

Human monosomics most often fail to survive prenatal development because the loss of a chromosome leads to a deficiency in essential genes and proteins. These deficiencies disrupt normal cellular function and the formation of tissues and organs, ultimately making it difficult for the individual to develop properly and survive.