Problem: Sandra liked all creatures but loved to study frogs. Her sister Julie studied more about fish and butterflies. They both loved nature. Which sister heard more male frogs "ribbiting"? Hint: You may hear males "ribbiting," producing a mating call used to attract females to the bodies of water best for mating and breeding. Frog calls can occur during the day or night. Each frog species has a different call that is used to attract mates and warn off rivals. When a female picks a male whose call she likes, the male grabs her and squeezes across her back and around her abdomen. This causes the female to release her eggs. The male then fertilizes the eggs and, in some species, also guards them.

A: Sandra

Problem: Adam was playing tag football when one of his friends tagged him a bit too hard and caused him to tumble and fall. He noticed when he fell, he got a pretty bad cut in his knee. He decided to ignore the injury for now and keep playing. Later when he got home he realized the area of the cut was warm and swollen Will the blood vessels near Adam's injury have expanded or contracted? Hint: The body's second line of defense against pathogens includes the inflammatory response. If bacteria enter the skin through a scrape, the area may become red, warm, and painful. These are signs of inflammation. Inflammation is one way the body reacts to infections or injuries. Inflammation is caused by chemicals that are released when skin or other tissues are damaged. The chemicals cause nearby blood vessels to dilate, or expand. This increases blood flow to the damaged area, which makes the area red and slightly warm. The chemicals also attract white blood cells called neutrophils to the wound and cause them to leak out of blood vessels into the damaged tissue.

A: expanded

Problem: Greg is a physician working for the city hospital. Today he is seeing two patients, patient A and patient B. He noticed that patient A's blood vessels are constricted, but blood vessels of patient B are dilated. He needs to prescribe medicine according to his observation. Which patient would have wider blood vessels, patient A or patient B? Hint: Blood vessels help regulate body processes by either constricting (becoming narrower) or dilating (becoming wider). These actions occur in response to signals from the autonomic nervous system or the endocrine system. Constriction occurs when the muscular walls of blood vessels contract. This reduces the amount of blood that can flow through the vessels (see Figure below ). Dilation occurs when the walls relax. This increases blood flows through the vessels.

A: patient B

Problem: Two friends had unprotected sex with their respective dates on the same night. Everything went fine for both of them. They later found out the bad news. Mike had been infected with HIV. Luckily enough Pete was healthy, he didn't get any diseases. Which friend didn't have a virus that is transmitted by contact with infected blood? Hint: The Human Immunodeficiency Virus ( HIV ) is the virus that causes Acquired Immunodeficiency Syndrome ( AIDS ). Most researchers believe that the HIV originated in sub-Saharan Africa during the 20th century. HIV is transmitted by sexual contact and by contact with infected bodily fluids, such as blood, semen, breast milk, and vaginal secretions. It is also passed from mother to fetus. HIV is now a pandemic , with an estimated (as of 2008) 38.6 million people now living with the disease worldwide. It is estimated that AIDS has killed more than 25 million people since it was first recognized in 1981. For further information about HIV/AIDS, see the CDC (Centers for Disease Control and Prevention) web site at http://www.cdc.gov/hiv/resources/factsheets/ .

A:
Pete