Final answer:
Genetic disorders can be caused by both recessive and dominant genes. Recessive disorders require two copies of the gene to manifest, while dominant ones can show with only one. Genetic mutations, which can be inherited, are responsible for various disorders, including cancer and chromosomal abnormalities like Down syndrome. The correct option is C) If one inherits a gene for a specific disease, and the gene is recessive, the disease is not always present.
Step-by-step explanation:
Understanding Genetic Diseases:
When considering which statement correctly describes genetic diseases or disorders, it is clear that option C) 'If one inherits a gene for a specific disease, and the gene is recessive, the disease is not always present.' is the most accurate. This is because autosomal recessive disorders such as cystic fibrosis require an individual to inherit two copies of the mutant gene, one from each parent, to exhibit the disease. However, carrying one copy of the recessive gene (being a carrier) does not usually result in showing any symptoms of the disease. On the other hand, autosomal dominant disorders, like Huntington's disease, can manifest even if only one copy of the dominant gene is present.
It is important to note that some genetic disorders can be due to dominant genes, contrary to option A). Mutations do not always cause disease as stated in option B), and not all mutations lead to genetic disorders. Additionally, the possibility of passing on a gene that carries a genetic disease to offspring exists, which makes option D) incorrect.
Some genetic disorders are also linked to mutations in chromosomes, such as Down syndrome, which is characterized by an extra chromosome 21. Moreover, environmental factors alongside genetic predispositions can influence the onset of some diseases such as cancer.