Question

Meiosis a. occurs in all eukaryotes b. supports growth and tissue repair in multicelled species c. gives rise to genetic diversity among offspring d. is part of the life cycle of all cells

Short answer

Option C: Meiosis gives rise to genetic diversity among offspring.

Step-by-step solution

Understanding the Process of Meiosis

Meiosis is a type of cell division that is specific to certain cells in an organism, aiming to produce gametes (sperm and egg cells) in sexually reproducing organisms. Unlike mitosis, meiosis reduces the chromosome number by half, resulting in unique haploid cells.

Evaluating Option A

Option A states that meiosis occurs in all eukaryotes. This statement is incorrect because not all eukaryotes undergo meiosis. Only organisms that reproduce sexually, like animals, plants, and some fungi, require meiosis.

Evaluating Option B

Option B claims that meiosis supports growth and tissue repair in multicelled species. This is a description of mitosis, not meiosis. Meiosis doesn't contribute to tissue repair or growth; it is involved in the formation of gametes.

Evaluating Option C

Option C states that meiosis gives rise to genetic diversity among offspring. This is correct, as meiosis includes processes like crossing over and independent assortment, which introduce genetic variation in gametes and hence among offspring.

Evaluating Option D

Option D suggests that meiosis is part of the life cycle of all cells. This is incorrect because meiosis is specifically for producing gametes; only those cells that will become gametes undergo meiosis.

Conclusion

Based on the evaluation of each option, option C is the correct answer. Meiosis creates genetic diversity among offspring through mechanisms that mix genetic information differently in each gamete.

Key concepts

Genetic Diversity

Genetic diversity is a crucial aspect of the biological world, especially in organisms that reproduce sexually. During the process of meiosis, which forms the basis for sexual reproduction, genetic diversity is achieved through specific mechanisms.
One such mechanism is **crossing over**. During meiosis, chromatids (the arms of chromosomes) exchange segments with each other. This process results in new allele combinations on each chromosome, ensuring that each gamete is genetically unique.
Another significant process contributing to genetic diversity is **independent assortment**. This is when chromosomes are distributed randomly into gametes. Imagine having a set of colored marbles in two bags; how you pick one marble and put it into another bag without looking represents how genes are randomly assorted. Because of this randomness, countless different combinations can arise. This culminates in offspring that have genetic variations distinct from their parents and siblings.

• Crossing Over: Exchange of chromosome segments during meiosis.
  
• Independent Assortment: Random separation of chromosomes into gametes.
  
• Results in uniqueness of traits in offspring.
  

Genetic diversity serves an essential role in the survival and evolution of species, by providing a pool of variations for populations to adapt to changing environments.

Sexual Reproduction

Sexual reproduction is an intricate process with far-reaching implications in the realm of biology. It involves the fusion of male and female gametes, mainly sperm and egg cells, which are produced via meiosis.
Unlike asexual reproduction, where offspring are clones of the parent, sexual reproduction combines the genetic material from two parents.
This is accomplished through fertilization, where the haploid sperm and haploid egg merge to form a diploid zygote, resetting the chromosome number to its full count.
Sexual reproduction thus not only generates genetic diversity, as discussed earlier, but also perpetuates species over generations.

• Fusion of gametes: Male and female gametes come together to create a new organism.
  
• Genetic Mixing: Offspring have combined traits from both parents.
  
• Maintains diploid chromosome number: Combines haploid cells to form a diploid zygote.
  

This process allows species to better adapt to environmental changes by offering a variety of genetic combinations that may enhance survival and reproduction, promoting evolutionary advancement.

Haploid Cells

Haploid cells play a pivotal role in sexual reproduction. They are formed through the process of meiosis, where the chromosome number is halved from diploid to haploid, effectively creating gametes that contain a single set of chromosomes.
In humans, for instance, while somatic cells are diploid, containing 46 chromosomes, gametes such as sperm and egg cells are haploid, bearing only 23 chromosomes.
This reduction is crucial to maintain the species' chromosome number across generations.

• Meiosis: Produces haploid cells for reproduction.
  
• Ensures consistent chromosome number: Prevents doubling in each generation.
  
• Found in gametes: Integral for sperm and egg cells.
  

Once two haploid cells fuse during fertilization, a diploid zygote is formed, restoring the full chromosome number. This process ensures genetic continuity and variation, vital for species survival and adaptation over time.