Logic of a solution: *Sponges are a source of food for many species of fish. Sponges are also keystone species. Keystone species are a source of food for many fish species.*
*(D)*
The original question: *What are a source of food for many fish species?
Options:
- (A) layers of fat
- (B) bird species
- (C) human species
- (D) keystone species
- (E) Organic compounds
- (F) barnacles
- (G) gastropod shells
- (H) species of deer*

Line 1: *Petals attract pollinators to the flower. Pollination is by flies, wasps, and bees. Petals attract flies, wasps, and bees to the flower.*
*(A)*
Line 2: *In order to attract flies, wasps, and bees, what does a flower employ?
Options:
- (A) petals
- (B) colors
- (C) insects
- (D) camouflage
- (E) Energy
- (F) scentless
- (G) lack of color
- (H) pollen*

Logic of a solution: *Vesicle transport requires energy, so it is also a form of active transport. Active transport is another form of diffusion. Vesicle transport is a form of diffusion.*
*(A)*
The original question: *Vesicle transport is a form of _.
Options:
- (A) diffusion
- (B) animals
- (C) communication
- (D) movement
- (E) direct energy
- (F) resistance
- (G) Vibrations.
- (H) motion*

Line 1: *Adult echinoderms have radial symmetry. Animals with radial symmetry lack an anterior and posterior end. Adult echinoderms lack an anterior and posterior end.*
*(D)*
Line 2: *Which of the following does not have an anterior and posterior end?
Options:
- (A) Adult mammals
- (B) Adult reptiles
- (C) Adult birds
- (D) Adult echinoderms
- (E) Earth orbiting the Sun
- (F) an erupting volcano
- (G) peachleaf willow
- (H) sensory neurons*

Logic of a solution: *Dilation occurs when cell walls relax. Slowly leg muscles ease up and shoulders relax. Dilation occurs when cell walls ease up.*
*(C)*
The original question: *What occurs when cell walls ease up?
Options:
- (A) root growth
- (B) air cools
- (C) dilation
- (D) sweating
- (E) Dehydration
- (F) recovery
- (G) Exfoliation
- (H) less water*

Logic of a solution: *Fertilization of gametes produces a diploid zygote. Sexual reproduction requires formation of gametes, followed by fertilization. Sexual reproduction produces a diploid zygote.*
*(E)*
The original question:
*What produces a diploid zygote?
Options:
- (A) salamanders
- (B) Plant reproduction
- (C) peachleaf willow
- (D) permineralization
- (E) sexual reproduction
- (F) Veins and arteries.
- (G) Chlorophyll
- (H) Most plants*