Q: What are the two types of photoreceptors in the retina? Choices: - holes and cones - circles and cones - images and cones - rods and cones A:
rods and cones

Q: What zone is outside the radiative zone? Choices: - diffusion zone - activation zone - peripheral zone - convection zone A:
convection zone

Q: Q: What is the upper-most atmosphere known as? Choices: - xerosphere - exosphere - ionosphere - thermosphere A:
A: thermosphere

Question: Q: What are liverworts with a flattened, ribbon-like body called? Choices: - hepatic liverworts - hornworts - kidney liverworts - thallose liverworts A:
Answer: thallose liverworts

*Question*
Q: What makes the earth habitable for humans? Choices: - carbonate of water - aridity of water - availability of water - abundance of water A:
**Answer**
abundance of water

Q: Q: Because plants lack what kind of system, their first line of defense is usually the death of cells surrounding infected tissue to prevent spread of infection? Choices: - nervous system - digestion system - hormones system - immune system A:
A: immune system