Answer/Explanation:
Down's syndrome - individuals with Down Syndrome have an extra copy of chromosome 21 (trisomy 21). This causes affected individuals to have learning disabilities as well as a range of health problems such as heart problems, growth delay, and characteristic facial features.
Turner syndrome - individuals with Turner Syndrome only have one X chromosome, but no Y chromosome (written XO). They are phenotypically female, but lacking the second X chromosome. This means they have underdeveloped ovaries, and are infertile. They also have a range of other features such as a short stature, a thick neck, and heart issues.
