A radioactive tracer has a half life of 2 hours. How much of a 2500 g sample will be available after 24 hours?

A) 2.44 g

B) 1.22 g

C) 0.610 g

D) 0.31 g

Name two ways that scientists share their experimental results with other scientists

What is the formula for iron (ll) sulfide?

What can we say about the frequency of x-linked recessive traits?

Which is not part of your immune system's response to a disease-causing organism? Answers: A. Vaccination B. Recognition C. Disposal D. Immunity My answer: D

All living things are classified into kingdoms based on specific characteristics. Which of the following are only characteristic to the Bacteria domain?

Switching from incandescent bulbs to compact fluorescents (cfl) provides a two-fold benefit during the summer. why?

What is the difference between osmosis and diffusion?

Which of the following is a serious threat to underground water supplies

1. Springs form where groundwater sinks into the soil there is no water table the water table intersects the ground surface flooding makes streams overflow their banks

Bio 254 - Pre-Class Assignment 1 Fill in the blanks 1. The "first line of defense" in innate immunity is 2. Histamine kinins, and interleukins are examples of