Disease, Defence and Human Health

How the body defends itself, how disease spreads, and single-gene inheritance read from a Punnett square.

10 questions, free, marked as you go with a worked explanation on every one.

What this covers

Two parents are each carriers of a recessive condition, with genotypes Aa and Aa. Using a Punnett square, what percentage of their children would be expected to have the condition (genotype aa)?
One parent has genotype Aa and the other has genotype aa for the same single gene. What percentage of their children would be expected to be carriers or affected, meaning they carry at least one lower-case a?
Two carrier parents (Aa x Aa) have a large number of children studied across many families, 200 children in total. Approximately how many would be expected to be carriers with genotype Aa?
What is the key difference between a bacterial infection and a viral infection for treatment?
Why does taking only part of a prescribed course of antibiotics contribute to antibiotic resistance?
How does a vaccine protect a person from a disease?
Which of these is a non-specific first line of defence against infection?
In a workplace of 250 people, 8% report a seasonal illness in one week. How many workers is that?
Use the table. A is dominant for purple flower colour over a. Construct a Punnett square for this cross. What percent of the offspring are expected to show the dominant phenotype?
Use the table. A is dominant over a. Construct a Punnett square for this cross. What percent of the offspring are expected to be homozygous dominant (AA)?