Why are family members different?

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Discussion Overview

The discussion centers on the reasons for physical differences between siblings, specifically questioning why siblings are not identical despite sharing chromosomes inherited from their parents. The scope includes genetic mechanisms, such as meiosis and genetic recombination, and touches on concepts of inheritance and variation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions why siblings are not twins by default and whether zygotes are identical from the start, expressing uncertainty about the underlying genetic processes.
  • Another participant explains that homologous chromosomes are separated during gamete formation, suggesting that the genetic variation arises from the random combination of chromosomes from each parent.
  • Further elaboration is provided on meiosis and genetic recombination, detailing how DNA is mixed and unique combinations are produced, leading to differences between siblings.
  • A later reply acknowledges the previous explanations, indicating a recognition of the complexity involved in genetic inheritance.

Areas of Agreement / Disagreement

Participants generally agree on the mechanisms of genetic variation, such as meiosis and recombination, but the initial question about why siblings are not identical remains open to exploration without a definitive consensus.

Contextual Notes

The discussion does not address potential limitations or assumptions regarding genetic inheritance, such as environmental factors or epigenetics, which may also contribute to physical differences.

david2
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i mean why is my brother physically different then me. why aren't we twins by default? don't we have the same chromosomes inhererented from our parents?

aren't zygotes the same from the start?

dumb question prolly, but i do not have the answer.

are chromosomes copied with errors or something or are other factors come into play?

thx
 
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david2 said:
i mean why is my brother physically different then me. why aren't we twins by default? don't we have the same chromosomes inhererented from our parents?

aren't zygotes the same from the start?

dumb question prolly, but i do not have the answer.

are chromosomes copied with errors or something or are other factors come into play?

thx
Homologous chromosomes is separated while sperms and eggs are generated,and the two separated string will enter two different sperms or eggs,which essentially means that your om and dad are flipping coins on every one of your body features,which makes you and your brother different,cause there coin flipping results re different.
 
During meiosis, which is the type of cell division that creates gametes (sperm and eggs), genetic recombination occurs that takes DNA from one-half of a chromosome and copies it to the other. Each chromosome is composed of a pair of chromatids, which are the 'arms' and 'legs' of a chromosome. For each chromosome, you get one chromatid from your father and one from your mother. Recombination swaps DNA between each chromatid so that the new chromatids are unique and different from either of the parent chromatids.

In other words, the DNA from your parents is mixed together and a unique combination comes out of the process, which is where the differences between siblings comes from.

See this link for more info: https://en.wikipedia.org/wiki/Chromosomal_crossover
 
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Drakkith said:
During meiosis, which is the type of cell division that creates gametes (sperm and eggs), genetic recombination occurs that takes DNA from one-half of a chromosome and copies it to the other. Each chromosome is composed of a pair of chromatids, which are the 'arms' and 'legs' of a chromosome. For each chromosome, you get one chromatid from your father and one from your mother. Recombination swaps DNA between each chromatid so that the new chromatids are unique and different from either of the parent chromatids.

In other words, the DNA from your parents is mixed together and a unique combination comes out of the process, which is where the differences between siblings comes from.

See this link for more info: https://en.wikipedia.org/wiki/Chromosomal_crossover
Way more professional then me!
 
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thanx for the answers
 

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