You have been asked to share with a group of learners in a health course why it is important to
protect their skin from the sun's rays. While you
are explaining sunburns and the importance of
sunscreen, one of the group members asks, "If
the sun is so harmful, why does it not cause radi-
ation burns?"
You present the diagram below to answer the
question. Which layer should you point out dur-
ing your explanation?
A. Exosphere
B. Thermosphere
C. Ozone Layer
D. Troposphere

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

Approximately 90% of all cases of polycystic kidney disease are inherited in an autosomal dominant fashion. the disease is typically related to mutations to genes (pkd1 and pkd2). pkd genes can be found on chromosome 16. the disease occurs in approximately 1: 800 to 1: 1000 people. here is a hypothetical example. the dominant allele d will cause the development of pkd. the recessive allele is known as d. what genotypes would correspond to suffering from pkd? dd, dd what genotypes would correspond to being normal (not suffering from pkd)? dd consider that 1: 1,000 people have pkd in your population of 325million. consider that pkd is inherited in an autosomal dominant fashion. show you math for all of the following questions: what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is p? what is q? how many people in your population would have pkd?

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays