The alleles found in haploid organisms cannot be dominant or recessive. Why? a. Dominance and recessiveness describe which of two possible phenotypes are exhibited when two different alleles occur in the same individual. b. Because only one allele is present, alleles in haploid organisms are always dominant. Ac. lleles in haploid individuals are transmitted like mitochondrial DNA or chloroplast DNA. d. Most haploid individuals are bacteria, and bacterial genetics is completely different from eukaryotic genetics.

Verified step by step guidance

1. Understand the concept of haploid organisms: Haploid organisms have only one set of chromosomes, meaning they possess only one allele for each gene.
2. Recognize the meaning of dominance and recessiveness: These terms describe the interaction between two different alleles of the same gene in a diploid organism, where both alleles influence the phenotype.
3. Analyze the options: Option a explains that dominance and recessiveness are terms used to describe the phenotype expression when two different alleles are present in the same individual, which is not possible in haploid organisms as they have only one allele per gene.
4. Eliminate incorrect answers: Options b, c, and d introduce irrelevant or incorrect explanations about the nature of alleles in haploid organisms or their genetic transmission.
5. Conclude the correct answer: Since haploid organisms have only one allele per gene, there is no second allele to compare for dominance or recessiveness, making option a the correct answer.

Key Concepts

Haploid Organisms

Haploid organisms contain only one set of chromosomes, meaning they have a single allele for each gene. This contrasts with diploid organisms, which have two alleles per gene, allowing for the expression of dominant and recessive traits. In haploids, since there is only one allele present, the concept of dominance does not apply.

Dominance and Recessiveness

Dominance and recessiveness refer to the relationship between alleles in diploid organisms. When two different alleles are present, the dominant allele masks the effect of the recessive one, leading to a specific phenotype. In haploid organisms, the absence of a second allele means that this relationship cannot exist, as there is no alternative allele to compare against.

Genetic Transmission in Haploids

In haploid organisms, genetic information is transmitted without the complexities of dominant and recessive interactions. This is particularly relevant in organisms like bacteria, where genetic material can be transferred through mechanisms such as horizontal gene transfer. Understanding this transmission is crucial for grasping how traits are inherited in haploid species.