The half-life of radon-222 is about four days. How long will it take for a sample of radon-222 to decay to 3% of its original amount?

Name the sporozoans responsible for the greatest number of human deaths. What disease does it cause and how it is transmitted?

Ricardo listed characteristics of three types of fungi in a chart. Which headings correctly complete the chart? 1. X: Club fungi Y: Zygote fungi Z: Sac fungi 2. X: Zygote fungi Y: Sac fungi Z: Club fungi 3.

Volcanoes are often formed at plate boundaries. This is a convergent plate boundary. From the choices listed, pick the correct description of what happens before the volcano forms. A) Denser continental plate pushes oceanic plate down.

Do you think that having chloroplasts gives plant cells an advantage over animal cells? give support for your opinion.

What organisms "fix" nitrogen, which allows plants to make amino acids?

If a molecule is too large to slip through the spaces in the membrane, how will that molecule enter the cell? A. The molecule will shrink so that it can fit in the spaces. B. The molecule will move through a protein channel. C.

What symbol indicates the cardinal directions

Which will have a better chance of surviving a major change in the environment where it lives: A) A bacteria strain with only twenty minutes between generations B) A large mammal (like bears) with decades between generations Explain your choice

What are the three-letter "words"of mRNA

What are the two ways that carbon enters into the atmosphere?