Answer:
A Jewish couple is about to be married but they both worry about their family history. The man's uncle and the women's aunt died of Tay Sachs disease. Infer why the couple is hiring a genetic counselor analyze their families pedigree.
Reasons are not far-fetched, both intended couple might carry a dominant gene for Tay Sachs disease or one of them has a dominant gene for such, it is pertinent a genetic counselor analyze their family pedegree in order to avoid having such disease or passing it to their offspring.
The chances of either of the intended couple to carry such dominant gene of the disease is imminent.
Explanation:
Your answer is actually all correct. Great job! A heterozygous combination would just implicate greater power to the 'dominant' dominant allele.
Answer: Potassium-40 decays into argon gas over time.
Explanation: Potassium-argon dating is a dating method used to determine the age of sedimentary rocks by comparing the proportion of K-40 to Ar-40 in a sample of rock, and knowing the decay rate of K-40.
Potassium-40 undergoes decay following first order kinetics as given below:

Answer: Single covalent bond in the long hydrocarbon chain.
Saturated fatty acids are long chains of hydrocarbon ( with single covalent bond) ending with the carboxylic group (-COOH). This means those fatty acids which possess only single bonds in their chemical structure are called as saturated fatty acids. They are densely packed, which makes them solid at room temperature.
Example- Lauric acid ( present in coconut oil). It has 12 carbon atoms in its chemical structure.