Sperm and eggs in humans always ________.
a. Each have two copies of every gene.
b. Each have one copy of every gene.
c. Each contain either all recessive alleles or all dominant alleles.
d. Are genetically identical to all other sperm or eggs produced by that person.
e. Each contain all of the genetic information from their producer.

Verified step by step guidance

1. Understand that sperm and eggs are gametes, which are specialized cells involved in sexual reproduction. Gametes are produced through a process called meiosis.
2. Recall that meiosis reduces the chromosome number by half, so that each gamete contains only one set of chromosomes (haploid), as opposed to the two sets (diploid) found in somatic cells.
3. Recognize that each chromosome in a gamete carries one copy of each gene, which is why gametes have one copy of every gene. This ensures that when sperm and egg combine during fertilization, the resulting zygote will have two copies of each gene (one from each parent).
4. Eliminate incorrect options: (a) is incorrect because gametes do not have two copies of every gene; (c) is incorrect because gametes contain a mix of alleles, not exclusively recessive or dominant; (d) is incorrect because gametes are genetically unique due to crossing over and independent assortment during meiosis; (e) is incorrect because gametes do not contain all genetic information from their producer, only half.
5. Conclude that the correct answer is (b), as sperm and eggs each have one copy of every gene, ensuring proper genetic contribution during fertilization.

Key Concepts

Meiosis

Meiosis is a specialized form of cell division that reduces the chromosome number by half, resulting in the production of gametes (sperm and eggs) with one copy of each chromosome. This process ensures genetic diversity through recombination and independent assortment, leading to gametes that are genetically distinct from one another and from the parent organism.

Haploidy

Haploidy refers to the condition of having a single set of chromosomes, which is characteristic of gametes in sexually reproducing organisms. In humans, sperm and eggs are haploid cells, containing one copy of each gene, which is crucial for maintaining the correct chromosome number upon fertilization when two haploid gametes combine to form a diploid zygote.

Genetic Variation

Genetic variation is the diversity in gene frequencies within a population, which arises from processes such as mutation, recombination during meiosis, and independent assortment. This variation is essential for evolution and adaptation, as it provides the raw material for natural selection to act upon, ensuring that offspring are not genetically identical to their parents or to each other.