What contains the green pigment chlorophyll?
Options:
- (A) seeds
- (B) orchids
- (C) barnacles
- (D) cacti
- (E) plastids
- (F) ferns
- (G) Most plants
- (H) bioaerosols
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Let's think first: Chloroplasts contain the green pigment chlorophyll. Chloroplasts are the most familiar plastids. Plastids contain the green pigment chlorophyll.... So the answer is [(E)]


What may vary in size as well as shape, but all are very small?
Options:
- (A) keeping food fresh for long periods of time
- (B) disease-causing microorganisms
- (C) A solid geometric shape
- (D) Unequal radiation absorption
- (E) Small countries.
- (F) Shapewear.
- (G) A water well.
- (H) Basic units of the plant body.
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Let's think first: Cells vary in size as well as shape, but all cells are very small. Basic unit of the plant body is the cell. Basic units of the plant body vary in size as well as shape, but all are very small.... So the answer is [(H)]


What kind of animal doesn't have a respiratory or excretory system?
Options:
- (A) a fish
- (B) bears
- (C) ant
- (D) whale
- (E) humans
- (F) starfish
- (G) mammals
- (H) llama
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Let's think first: Echinoderms lack respiratory and excretory systems. Starfish and sea urchins are also echinoderms. Starfish lack respiratory and excretory systems.... So the answer is [(F)]


What falls decreasingly on the earth from the equator to the poles?
Options:
- (A) autumn
- (B) heat
- (C) chill
- (D) Vapor
- (E) Energy
- (F) cold
- (G) summer
- (H) Mass
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Let's think first: Temperature falls from the equator to the poles. Temperature is a measure of the amount of heat. Heat falls from the equator to the poles.... So the answer is [(B)]


_ have the amazing capacity to regrow segments.
Options:
- (A) ferns
- (B) arachnids
- (C) roots
- (D) earthworms
- (E) anthropods
- (F) crustacean
- (G) loose soil
- (H) root growth
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Let's think first: Annelids have the amazing capacity to regrow segments that break off. Earthworms Earthworms are in the phylum Annelids. Earthworms have the amazing capacity to regrow segments that break off.... So the answer is [(D)]


The cells that produce antibodies are key in what system?
Options:
- (A) health
- (B) T cells
- (C) vision
- (D) humans
- (E) macrophages
- (F) B cells
- (G) disease
- (H) immune
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Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Let's think first: Lymphocytes are the key cells involved in the immune response. B lymphocytes produce antibodies . The key cells involved in the immune response produce antibodies.... So the answer is [(H)]