Line 1: *Amphibians have a relatively complex circulatory system with a three-chambered heart. Frogs, toads and salamanders are amphibians. Salamanders have a relatively complex circulatory system with a three-chambered heart.*
*(B)*
Line 2: *Which animal has a circulatory system with a three-chambered heart?
Options:
- (A) animals
- (B) Salamander
- (C) fur seals
- (D) mammals
- (E) alpacas
- (F) a fish
- (G) warm-blooded
- (H) barnacles*

Logic of a solution: *Fungi lack chlorophyll, so they cannot make food by photosynthesis as plants can. Fungi decompose dead plant and animal matter. Since fungi cannot make food by photosynthesis, they decompose dead organisms.*
*(B)*
The original question: *Where do fungi get their food?
Options:
- (A) swamp vegetation
- (B) decomposing dead organisms
- (C) decomposition
- (D) the environment
- (E) mushrooms
- (F) By wind and rain
- (G) spores
- (H) carbon dioxide*

Line 1: *Viruses contain DNA but not much else. DNA DNA is deoxyribonucleic acid. Viruses contain deoxyribonucleic acid, but not much else.*
*(H)*
Line 2: *What do viruses contain the most of?
Options:
- (A) Chemical energy
- (B) layers of fat
- (C) ribonucleic acid
- (D) cytoplasm
- (E) germs
- (F) harmful substances
- (G) deadly and devastating
- (H) deoxyribonucleic acid*

Logic of a solution: *Biodiversity increases the productivity and stability of ecosystems. Biodiversity is basically genetic diversity. Genetic diversity increases the productivity and stability of ecosystems.*
*(C)*
The original question: *What increases the productivity and stability of ecosystems?
Options:
- (A) Fully cooking the oysters
- (B) genetic uniformity
- (C) genetic diversity
- (D) extinction
- (E) agriculture
- (F) disease
- (G) Earth orbiting the Sun
- (H) recycling*

Line 1: *Dilation occurs when cell walls relax. When oxygen level decreases, dilatation of the blood vessels occurs. Decreased oxygen levels cause blood vessels to dilate and cell walls to relax.*
*(E)*
Line 2: *What causes cell walls to relax?
Options:
- (A) exercise
- (B) sweating
- (C) adding heat
- (D) Energy
- (E) dilation
- (F) heat or cold
- (G) heat
- (H) Dehydration*

Line 1: *Echinoderms lack respiratory and excretory systems. Echinoderms are represented by the starfish. Starfish lack respiratory and excretory systems.*
*(C)*
Line 2:
*What lacks respiratory and excretory systems?
Options:
- (A) the Sun
- (B) insects
- (C) starfish
- (D) barnacles
- (E) ferns
- (F) water
- (G) Conifers
- (H) humans*