What is a complex protein-iron compound in blood that carries oxygen to cells?

Where do spindle fibers form?

When a nerve reaches the end of an axon ___ A) The impulse bounces back B) The signal stops C) A chemical signal is released D) A electrical Signal is released

In an experiment in the laboratory, a small colored molecule is injected into one cell. Within minutes, the molecule has entered the adjacent cells. What type of junctions connect these cells?

Biotechnology is used in a variety of areas from agriculture to pharmaceuticals to fuels. How is the use of biotechnology in agriculture beneficial to the environment? Genetically altered crops are unable to reproduce.

What was Mohorovičić's observation? Seismic waves travelled at constant speeds. Seismic waves penetrated all Earth's layers. Seismic waves could not go through the brittle crust. Seismic waves travelled at varying speeds.

In what ways are index fossils and layers of volcanic ash found in ice cores similar?

The percentage of silt in silty clay loam is what? a. 60% to 70% b. 80% to 90% c. 90% to 100% d. 10% to 20%

Which of the following would cause an error in DNA replication? A. DNA ligase taking apart chunks of DNA B. Helicase making a replication fork C. DNA polymerase pairing new Cs with Gs D. DNA polymerase checking the DNA

Which of the following about Dalton's theory of matter is true? A Atoms of the same element have the same mass. B Compounds formed from two elements will not always have the same proportions. C Atoms cannot be divided into smaller parts.

What would cause a particular polygenic trait, like tall stature in humans, to become more frequent in a population over time?