Which of the following characterizes parthenogenesis in the life cycle of sexual reproducers?

• A. Development of an embryo from an unfertilized egg
• B. Fusion of gametes from two different individuals
• C. Production of offspring through binary fission
• D. Alternation between haploid and diploid generations

Answer: (A)

Verified step by step guidance

1. Understand the concept of parthenogenesis: Parthenogenesis is a form of asexual reproduction where an embryo develops from an unfertilized egg cell. This process does not involve the fusion of gametes from two different individuals.
2. Differentiate between sexual and asexual reproduction: In sexual reproduction, offspring are produced by the fusion of gametes (sperm and egg) from two different individuals, leading to genetic variation. In asexual reproduction, such as parthenogenesis, offspring are produced without the fusion of gametes, resulting in genetically identical offspring to the parent.
3. Identify the characteristics of parthenogenesis: Since parthenogenesis involves the development of an embryo from an unfertilized egg, it does not involve the fusion of gametes or alternation between haploid and diploid generations, which are typical of sexual reproduction.
4. Eliminate incorrect options: The option 'Fusion of gametes from two different individuals' describes sexual reproduction, not parthenogenesis. 'Production of offspring through binary fission' is a form of asexual reproduction but not parthenogenesis. 'Alternation between haploid and diploid generations' is a characteristic of some plants and algae, not parthenogenesis.
5. Conclude with the correct characterization: The correct characterization of parthenogenesis in the life cycle of sexual reproducers is 'Development of an embryo from an unfertilized egg.'