Answer the following question given this paragraph: Because alkanes contain only CC and CH bonds, which are strong and not very polar (the electronegativities of C and H are similar; Figure 7.15 "Pauling Electronegativity Values of the "), they are not easily attacked by nucleophiles or electrophiles. Consequently, their reactivity is limited, and often their reactions occur only under extreme conditions. For example, catalytic cracking can be used to convert straight-chain alkanes to highly branched alkanes, which are better fuels for internal combustion engines. Catalytic cracking is one example of a pyrolysis reaction (from the Greek pyros, meaning "fire," and lysis, meaning "loosening"), in which alkanes are heated to a sufficiently high temperature to induce cleavage of the weakest bonds: the CC single bonds. The result is a mixture of radicals derived from essentially random cleavage of the various CC bonds in the chain. Pyrolysis of n-pentane, for example, is nonspecific and can produce these four radicals: Equation 24.7. Q: When do alkane reactions usually occur? Choices: - underwater - at high altitudes - in cold climates - under extreme conditions A:
under extreme conditions
Answer the following question given this paragraph: Law stating that matter cannot be created or destroyed in chemical reactions. Q: What cannot be created or destroyed in a chemical reaction? Choices: - heat - mass - energy - matter A:
matter
Q: Answer the following question given this paragraph: In terms of moisture, climates can be classified as arid (dry), semi-arid, humid (wet), or semi-humid. The amount of moisture depends on both precipitation and evaporation. Q: What is the scientific term for climates with the least moisture? Choices: - mediterannean - tropical - polar - arid A:
A: arid
Question: Answer the following question given this paragraph: In 1966, Francis Crick proposed the Wobble Hypothesis which explained that the degeneracy of the genetic code is caused by the structure of the anticodon of tRNA. The anticodon is a three base sequence on the tRNA complementary to the codon on the mRNA. Each tRNA binds to a specific amino acid, but the anticodons of some tRNA molecules can bind to two or three different codons. This flexibility of the anticodon is caused by the less stringent 5' base on the anticodon loop, also referred to as the wobble base, which binds to the 3' base on the mRNA. Only the first two nucleotides are stringent and spatially confined for the decoding of the mRNA codon into an amino acid. This explains why degenerate codons often differ in the third position, as depicted in Figure above . For example, the amino acid alanine is coded by codons GCU, GCC, GCA and GCG. The wobble movement of the base in the 5' anticodon position is necessary for this degenerate capability. Q: What is used in the growth, development, functioning and reproduction of all known living organisms and many viruses? Choices: - viruses - bacteria - enzymes - dna A:
Answer: dna
*Question*
Answer the following question given this paragraph: The process of cellular respiration can be thought of as a highly controlled version of a combustion reaction. We do not literally burn hydrocarbons in our body, but the overall reactants and products are the same. Hydrocarbons, such as sucrose (C 12 H 22 O 11 ), are combined with oxygen in a series of enzymatic steps to product water, carbon dioxide, and energy, which is stored in the form of reactive molecules. The unbalanced chemical equation for this overall process is shown below:. Q: Hydrocarbons are combined with oxygen in a series of enzymatic steps to product water, carbon dioxide, and energy, which is stored in the form of what? Choices: - energy - dormant molecules - light - reactive molecules A:
**Answer**
reactive molecules
Answer the following question given this paragraph: The first vertebrates to live fully on land were amniotes. Amniotes are animals that produce eggs with waterproof membranes. The membranes let gases but not water pass through. They allow embryos to breathe without drying out. Amniotic eggs were the first eggs that could be laid on land. The earliest amniotes evolved about 350 million years ago. Amniotes would eventually evolve into modern reptiles, mammals, and birds. Q: Amniotes are animals that produce eggs with membranes possessing what property, which allowed them to lay eggs on land? Choices: - absorbent - heavy - hard - waterproof A:
waterproof