Alternative instructions for a single protein are encoded on:
Options:
- (A) alleles
- (B) Acids
- (C) PDAs
- (D) nucleus
- (E) junk DNA
- (F) A computer
- (G) inheritance
- (H) Tail
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Let's think first: Most genes contain the instructions for a single protein. Alleles are alternative forms of a gene. Alleles can contain instructions for making alternative versions of the same single protein.... So the answer is [(A)]


Sperm had to swim from what to what reproductive organs for zygotes to occur.
Options:
- (A) barnacles
- (B) male to female
- (C) animals
- (D) ocean water
- (E) male to male
- (F) mouth of rivers
- (G) female to male
- (H) female to female
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Let's think first: Sperm had to swim from male to female reproductive organs for fertilization. If fertilization occurs, the fertilized eggs are now described as pre-embryos or zygotes. Sperm had to swim from male to female reproductive organs for zygotes to occur.... So the answer is [(B)]


What can frogs, toads and salamanders use to smell and taste chemicals?
Options:
- (A) sense organs
- (B) Chemical energy
- (C) matter vibrating
- (D) larynx
- (E) Organic compounds
- (F) ocular organs
- (G) gills
- (H) harmful substances
--
Let's think first: Amphibians have sense organs to smell and taste chemicals. Frogs, toads and salamanders are amphibians. Frogs, toads, and salamanders have sense organs to smell and taste chemicals.... So the answer is [(A)]


How are atolls built?
Options:
- (A) important habitats
- (B) By coral exoskeletons
- (C) by fish
- (D) with machines
- (E) by a type of eel
- (F) It used to be covered by water
- (G) The area was once underwater
- (H) reusing materials
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Let's think first: Many corals secrete an exoskeleton that builds up to become a coral reef. An atoll is the third type of reef. Atolls are built by corals secreting an exoskeleton.... So the answer is [(B)]


What can use photosynthesis?
Options:
- (A) fungi
- (B) grass
- (C) fish
- (D) vegetation
- (E) flowers
- (F) vertebrates
- (G) plant life
- (H) plants
--
Let's think first: Fungi lack chlorophyll, so they cannot make food by photosynthesis as plants can. Solar energy is absorbed by chlorophyll. Fungi cannot absorb solar energy and cannot make food by photosynthesis as plants can.... So the answer is [(E)]


What generally carries something bright red?
Options:
- (A) bears
- (B) veins
- (C) arteries
- (D) mammals
- (E) nerves
- (F) fur seals
- (G) Cars
- (H) bones
--

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: Arteries generally carry oxygen-rich blood. Oxygen-rich blood is bright red. Arteries generally carry something bright red.... So the answer is [(C)]