Why do sex cells (sperm and egg) need to have half the number of the organisms chromosomes

If this particular antigen attempts to re-infect Caleb, it's in for a bigger fight. By getting activation of adaptive immune cells such as B-cells and T-cells, the body generates an extra layer of protection.

Mutations in the Pax6 gene causes developmental defects in the eyes of flies, mice, and humans. This suggests that: a. Pax6 has been evolutionarily conserved. b. Pax6 activates multiple genes. c. Pax6 may be a master regulator of eye development. d.

Which of the following accurately describes nutrient limitation? A. If one essential nutrient within an ecosystem runs out, primary productivity will be limited. B. Soil environments aren't affected by nutrient limitation. C.

Quarantine be tough out here for a young black fellow!

What did Charles Darwin do that allowed him to make some significant observations about how organisms change over time?

What is ATP? A: the energy of moving electrons B: an energy-rich substance that cells need to survive C: an acidic substance that makes muscles cramp D: an organism that uses fermentation to produce energy

Both insulin and glucagon are peptide hormones that target liver cells. The response of the target cells to each of these two hormones is opposite. This information implies that

Why do plant cells need chloroplasts? Explain.

An extracorporeal liver assist device was surgically implanted into sam. this device is very similar to

A client has been diagnosed with depression and the primary care provider has believes that a sustained serotonin reuptake inhibitor would be effective.