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Scientists have tried to achieve a viable embryo by fusing two ova (eggs) from the same female - HSC - SSCE Biology - Question 29 - 2014 - Paper 1
Question 29
Scientists have tried to achieve a viable embryo by fusing two ova (eggs) from the same female. Explain whether the offspring produced using this process would be a... show full transcript
Worked Solution & Example Answer:Scientists have tried to achieve a viable embryo by fusing two ova (eggs) from the same female - HSC - SSCE Biology - Question 29 - 2014 - Paper 1
Step 1
Explain whether the offspring produced using this process would be a clone of the female whose two ova were used.
Answer
The offspring produced from fusing two ova from the same female would not be a clone in the strictest sense. While the two ova share the same maternal genetic material, the resulting embryo would have a unique combination of genetic information.
This is due to the nature of gamete formation. Each egg undergoes meiosis, where genetic variation is introduced through processes such as crossing over and independent assortment. During meiosis, homologous chromosomes exchange segments, leading to genetic diversity among the gametes. Additionally, the independent assortment of chromosomes ensures that each gamete (egg) contains different combinations of alleles.
When two genetically unique ova fuse, the resulting embryo will have a new combination of genetic information that differs from the genetic makeup of the original female. Therefore, while the offspring may carry some genetic traits from the female, it will not be an exact clone. A true clone would require that the offspring contain identical genetic material as the female.
Step 2
Use your knowledge of gamete formation and sexual reproduction to support your answer.
Answer
In sexual reproduction, two gametes (one from each parent) combine to form a zygote. In this scenario, since the two gametes are from the same female, it’s important to consider the events of meiosis.
Meiosis involves two rounds of cell division that results in four genetically distinct haploid gametes. Throughout this process, several mechanisms contribute to genetic variation:
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Crossing Over: During prophase I of meiosis, homologous chromosomes can exchange segments of DNA. This results in new allele combinations on the chromatids.
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Independent Assortment: Chromosomes are distributed randomly into gametes, meaning that each gamete can have different combinations of maternal and paternal chromosomes.
Consequently, if two ova are fused, they may produce an embryo with a unique genetic combination rather than an exact clone of the mother. This introduces variability in the offspring's genetic makeup, confirming that while they share genetic material, they are not clones.