Final answer:
Translocation Down syndrome can result in an individual having 46 chromosomes, where extra chromosome 21 material is attached to another chromosome. Typically, Down syndrome is associated with 47 chromosomes due to a trisomy 21 condition.
Step-by-step explanation:
An individual with Down syndrome can have 46 chromosomes under rare circumstances where the extra genetic material from chromosome 21 is translocated to another chromosome. This is known as the translocation of Down syndrome. Typically, the condition results in 47 chromosomes because of trisomy 21, where there are three complete copies of chromosome 21. The standard trisomy 21 occurs due to nondisjunction during meiosis, primarily associated with increased maternal age. Down syndrome features can include intellectual disability, distinct facial characteristics, and an increased risk of certain medical conditions. It is essential to note that with appropriate support, individuals with Down syndrome can lead fulfilling lives.