What keeps mammals warm?
Options:
- (A) evaporation
- (B) Animal fur
- (C) staying warm
- (D) sweating
- (E) They have thick fur
- (F) with their fur
- (G) a layer of fat
- (H) Veins and arteries.
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Let's think first: Mammals have a layer of fat under the skin to help insulate the body. Glass insulation keeps beverage warm for hours. Mammals have a layer of fat under the skin to keep them warm.... So the answer is [(G)]

What is part of the kidney structure?
Options:
- (A) thorax
- (B) glomerulus
- (C) organ
- (D) arteries
- (E) layers of fat
- (F) more abundant
- (G) pancreas
- (H) urine
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Let's think first: Nephrons are the structural and functional units of the kidneys. Each nephron has a glomerulus. Glomerulus is part of the kidney structure.... So the answer is [(B)]

What happens in the archegonium?
Options:
- (A) eggs separate
- (B) Earth orbiting the Sun
- (C) sperm and egg fuse
- (D) competition
- (E) fallopian tubes join
- (F) permineralization
- (G) It expands
- (H) cloning
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Let's think first: Fertilization occurs when sperm swim to an egg inside an archegonium. Fertilization occurs when the egg and sperm fuse and join. An egg and sperm can fuse when sperm swim to an egg inside an archegonium.... So the answer is [(C)]

Aging is associated with degrading:
Options:
- (A) Most plants
- (B) an object
- (C) Acids
- (D) telomeres
- (E) layers of fat
- (F) Chlorophyll
- (G) vegetation
- (H) the skin
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Let's think first: Aging is associated with the death of cells. Telomeres degrade as the cells divide and their shortening causes cell death. Aging is associated with degrading telomeres.... So the answer is [(D)]

What can be a source of food for many species of fish?
Options:
- (A) Fully cooking the oysters
- (B) Organic compounds
- (C) beef
- (D) fishing poles
- (E) sessile organisms
- (F) barnacles
- (G) grass
- (H) gastropod shells
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Let's think first: Sponges are a source of food for many species of fish. Most sponges are sessile. Sessile organisms can be a source of food for many species of fish.... So the answer is [(E)]

What can have special excretory systems?
Options:
- (A) feces
- (B) barnacles
- (C) animals
- (D) cacti
- (E) fungi
- (F) wings
- (G) soil
- (H) insects
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Let's think first: Some arthropods have special excretory structures. Insects are the largest group of arthropods. Some insects have special excrectory structures.... So the answer is [(H)]