The 2023 Guardian article discusses the positive impacts of delaying fatherhood on children’s health, with older fathers contributing 1-2 fewer SNPs/year than younger fathers.   

Scientists have discovered genetic variants that are associated with dyslexia.

Most cases of trisomy 21 occur because of an error in which meiotic division?

Choose the best answer from the choices below. A couple has a child with cystic fibrosis. Neither parent has cystic fibrosis. This couple wants to have a second child. What is the probability that this second child will have cystic fibrosis?

The pedigree below follows the inheritance of a rare disease in a family. This disease is characterized by weak bones, as well as other symptoms.  This pedigree most likely shows the inheritance of what kind of gene? Choose the best answer from the choices below.

Bob and Linda are a newly married couple. They hope to have a child but are having trouble getting pregnant. They visit a fertility clinic, where they receive genetic tests. One test shows that Bob is healthy but carries a single disease-causing allele for CFTR (the gene that can cause cystic fibrosis), but Linda does not. What type of genetic test was performed?

Attention-deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder with a major genetic component. ADHD is polygenic. In 2023, scientists examined  38,691 individuals with ADHD and 186,843 without ADHD. The scientists identified variants in 76 genes that were correlated with ADHD. These are considered risk variants. To develop ADHD does an individual’s genome need to have risk variants in all 76 genes? [No] Could one or more of these risk variants be found in the genomes of someone without ADHD? [Yes]

Sickle cell anemia is an autosomal recessive disease caused by a mutation in the gene that encodes the hemoglobin protein. Homozygous mutations in this gene lead to the production of mutant hemoglobin protein. When only mutant hemoglobin protein is produced, red blood cells (RBCs) adopt an abnormal sickle shape and their function is impaired. On December 8, 2023 the FDA approved Casgevy to treat sickle cell anemia. Casgevy is the first medical use of the CRISPR-Cas gene-editing system. Casgevy uses CRISPR-Cas9 technology to cut a gene in the genome. What gene is targeted by the Cas9 used in Casgevy?

A yeast strain was exposed to a chemical mutagen. As expected, exposure to mutagen resulted in a DNA sequence change in an essential gene (required for survival) you examined. Yet this mutation did not result in any lethal phenotype (cause death). Which of the following answers would BEST explain this apparent discrepancy?

The 2023 Guardian article discusses the positive impacts of delaying fatherhood on children’s health, with older fathers contributing 1-2 fewer SNPs/year than younger fathers.