Why might it be important to use different models at different stages of an investigation.

Are there more female or male in the world?

Red-green color blindness is a human X-linked recessive disorder. A young man with a 47, XXY karyotype (Klinefelter syndrome) is color blind. His 46, XY brother also is color blind. Both parents have normal color vision.

If the lithosphere moved less, how would the surface of the earth be affected

Strengthening tissue found in the cell walls of plants

The characteristics of an organism are identified by two factors. What are these two factors? (This problem relates to Meiosis.)

Genetic mutations pass to offspring in gametes because gametes A) are not germ cells. B) make up all internal organs. C) do not divide during mitosis. D) fuse during sexual reproduction.

How can you tell that a sperm cell is animal cell and not a plant cell?

The all-or-nothing principle means that a. All the nerve impulses go to the brain b. An entire neuron depolarizes to its maximum strength c. All the potassium ions on one side of the cell membrane move to the other side of the cell membrane d.

Saki went on vacation and was fortunate enough to get to see the aurora australis. What solar activity did she observe?

The first embryonic stem cell trials too place October 2010 to treat a patient. This patient had been left partially paralysed by nerve damage after a spinal injury. Explain why it is an advantage to use embryonic stem cells to treat spinal injuries.