question: What do nephrons filter?
Options:
- (A) Blood
- (B) matter
- (C) solutes
- (D) Energy
- (E) SO2
- (F) Gases
- (G) Energy.
- (H) cations
answer: Nephrons are the structural and functional units of the kidneys. Blood is filtered in the kidney. Nephrons filter blood.
The answer is (A)

question: Biodiversity increases the what of islands?
Options:
- (A) water source
- (B) stability
- (C) Plants growth
- (D) our planet
- (E) luminescence
- (F) environment
- (G) human population
- (H) allow growth
answer: Biodiversity increases the productivity and stability of ecosystems. Islands are delicately balanced ecosystems. Biodiversity increases the stability and productivity of islands.
The answer is (B)

question: What is something that has specialized reproductive organs?
Options:
- (A) animals
- (B) insects
- (C) Conifers
- (D) burrs
- (E) potatoes
- (F) rabbit
- (G) sharks
- (H) ducks
answer: Plants have specialized reproductive organs. Plant reproduction is similar to animal reproduction. Animals have specialized reproductive organs.
The answer is (A)

question: What is an arthopod with two wings?
Options:
- (A) rare
- (B) fly
- (C) two
- (D) host
- (E) Aves
- (F) male
- (G) bird
- (H) bats
answer:
Most arthropods are insects. Flies are insects with two wings. Flies are arthropods with two wings.
The answer is (B)