Suppose that you began a one-year study of tuberculosis (TB) in St. Petersburg on January 1st, 2018. You enrolled 200 residents in your study and checked on their TB status on a monthly basis. At the start of your study on January 1st, you screened all 200 residents. Upon screening, you found that 10 of the healthy residents were immigrants who were vaccinated for TB and so were not at risk. Another 10 residents already had existing cases of TB on January 1st. On February 1st, two residents developed TB. On April 1st, three more residents developed TB. On July 1st, three of the residents who had existing TB on January 1st died from their disease. The study ended on December 31, 2018. Assume that once a person gets TB, they have it for the duration of the study, and assume that all remaining residents stayed healthy and were not lost to follow-up. What was the prevalence of TB in the screened community on January 1st?

 5%

Explanation:

The Prevalence rate is the term used to describe the percentage of a population that have contacted the disease being tested for. It is usually done over a certain period or a certain time.

The prevalence of TB in the screened community on January 1st therefore is;

= Number of infected/ No. of Tested residents

= 10/200

= 5%

the two answers are a, the population of birds with large beaks will increase on the island, and c, the trait for large beaks will be passed on to future generations through natural selection. the reason for that is because if the birds that have beaks developed for eating small seeds lose all of their food, they will go hungry and eventually starve because they physically cannot eat the large seeds, therefore making the population of large beaked birds higher. also, if the trait of large beaks are dominant on the island over small beaks, then over time the large beaked birds will reproduce more and more, while the smaller beaked birds will reproduce less and less because they can't survive with the food provided. that leads to the trait of small beaks disappearing and the trait of large beaks taking over the island.

homeostasis is the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes. and this is how it applies to the integumentary system. back to top. skin functions in homeostasis include protection, regulation of body temperature, sensory reception, water balance, synthesis of vitamins and hormones, and absorption of materials. when body temperature falls, the sweat glands constrict and sweat production decreases.