Question

Why is there a greater level of genetic diversity for species that reproduce sexually compared to those that reproduce asexually? (A) The offspring of parents that reproduce sexually inherit only the traits from the dominant parent. (B) The offspring of parents that reproduce sexually inherit brandnew traits entirely unlike those of either parent. (C) Organisms that reproduce sexually tend to produce more offspring than those that reproduce asexually. (D) The offspring of parents that reproduce sexually inherit a mix of traits from both parents.

Short answer

The correct answer is (D) - The offspring of parents that reproduce sexually inherit a mix of traits from both parents. This leads to greater genetic diversity because sexual reproduction involves the sharing and combination of genetic material from two parents, resulting in variation within populations.

Step-by-step solution

Eliminate options unrelated to genetic diversity

We can eliminate options (A) and (C) as they do not directly relate to genetic diversity. Option (A) refers to dominant traits, which does not necessarily contribute to greater diversity. Option (C) talks about the number of offspring, which also does not directly impact genetic diversity.

Analyze option B

Option (B) suggests that the offspring of sexually reproducing parents have brand new traits entirely unlike those of either parent. While it can be true that offspring can have new traits, it wouldn't make sense for those traits to be completely unlike their parents'. Therefore, this option does not support greater genetic diversity in sexual reproduction correctly.

Analyze option D

Option (D) states that the offspring of sexually reproducing parents inherit a mix of traits from both parents. This statement is accurate, as sexual reproduction involves the combination of genetic material from two parents. This combination and sharing of genetic information lead to genetic diversity as offspring inherit traits from both parents, leading to variation within populations.

Choose the correct option

Based on our analysis, the correct answer is (D) - The offspring of parents that reproduce sexually inherit a mix of traits from both parents. This is because genetic diversity arises through the mixing and sharing of genetic information between two individuals in sexual reproduction, which is not present in asexual reproduction.

Key concepts

Genetic Inheritance

Genetic inheritance is at the heart of understanding how traits are passed down from parents to their offspring. It's a fundamental concept that explains how living organisms, including humans, inherit characteristics from their progenitors.

In sexual reproduction, genetic inheritance occurs through the fusion of gametes, which are reproductive cells from each parent with half the usual number of chromosomes. When an egg and sperm combine, they form a zygote with a complete set of chromosomes – half from the mother and half from the father. This process is known as fertilization.

The zygote then grows into a new individual, with genetic material from both parents. This mixing of genetic information, or recombination, is crucial for producing genetic variation. Traits are not just passed down as they are but are shuffled and recombined in new ways during the formation of gametes in a process called meiosis, further contributing to the genetic uniqueness of each individual.

Asexual vs Sexual Reproduction

The distinction between asexual and sexual reproduction is another critical aspect of biology that has direct implications on genetic diversity. Asexual reproduction involves a single organism giving rise to offspring without the involvement of fertilization by another.

Common asexual reproduction methods include binary fission, budding, and vegetative propagation. These processes result in offspring that are genetic clones of the parent, barring any mutations. Since there's no exchange of genetic material, the potential for genetic variation is much lower in asexual reproduction compared to sexual reproduction.

In contrast, sexual reproduction involves the combination of genetic material from two distinct parents. This blend creates diversity within the species, allowing for greater adaptability and survival in changing environments. Evolutionarily speaking, sexual reproduction is seen as a mechanism to enhance a population's ability to deal with pathogens and parasites through the generation of genetically diverse offspring.

Genetic Variation

Genetic variation is the spice of life when it comes to the resilience and adaptability of populations. It refers to the differences in DNA sequences among individuals within a population. These differences can be in the form of alleles, which are different versions of the same gene.

Sexual reproduction boosts genetic variation through mechanisms like crossing over during meiosis, where portions of DNA are exchanged between paired chromosomes. Mutations, which are changes in the DNA sequence, also contribute to genetic variation, albeit at a much lower rate compared to the shuffling of genes that occurs during sexual reproduction.

The significance of genetic variation cannot be overstated—it's the raw material that natural selection acts upon. Without genetic variation, a population can become susceptible to diseases or changes in the environment due to the lack of a varied gene pool. The greater the genetic variation within a population, the higher chance it has for some individuals to survive and reproduce under different environmental stresses, leading to a robust and adaptable population.