Final - Day 2

Cells synthesize protein by the process of translation. Organize the steps of translation in the correct sequence from beginning to end. (A) As the mRNA is read, the amino acids on each tRNA are joined by peptide bonds. (B) mRNA is transported to the rough endoplasmic reticulum. (C) A tRNA molecule aligns with the mRNA. (D) An amino acid is bound across from the anticodon region of each tRNA. (E) The anticodon region of a tRNA molecule pairs with the corresponding mRNA sequence. (F) Ribosomes bind to mRNA.

1. (B) mRNA is transported to the rough endoplasmic reticulum. 2. (F) Ribosomes bind to mRNA. 3. (C) A tRNA molecule aligns with the mRNA. 4. (E) The anticodon region of a tRNA molecule pairs with the corresponding mRNA sequence. 5. (D) An amino acid is bound across from the anticodon region of each tRNA. 6. (A) As the mRNA is read, the amino acids on each tRNA are joined by peptide bonds.

Organize the steps of transcription into the correct sequence from the beginning to the end of the process. (A) Complementary base pairs link to the DNA strand (B) RNA polymerase travels along the DNA strand until it reaches a terminator sequence (C) RNA polymerase binds to DNA (D) mRNA polymer detaches form DNA (E) A strand of RNA forms (F) DNA strands separate

1. (C) RNA polymerase binds to DNA 2. (F) DNA strands separate 3. (A) Complementary base pairs link to the DNA strand 4. (E) A strand of RNA forms 5. (B) RNA polymerase travels along the DNA strand until it reaches a terminator sequence 6. (D) mRNA polymer detaches form DNA

Study the process shown in the diagram below. Which statement summarizes the process shown in the diagram? A. DNA is being transcribed into mRNA. B. mRNA is being translated into mRNA. C. DNA is being replicated in preparation for cell division. D. Amino acids are joining together and folding into a protein.

A. DNA is being transcribed into mRNA.

Suppose an ecosystem suddenly loses all of it consumers to a disease. Which of the following scenarios would most likely happen? A. The ecosystem would become overgrown with plants. B. Plant-eating organisms would become abundant. C. Carnivores and omnivores would starve to death. D. Energy would no longer enter the ecosystem.

A. The ecosystem would become overgrown with plants.

An RNA molecule is suffering degradation by exoribonucleases that are cutting the ends of the strand. Why is this occurring? A. The ends were not modified during processing. B. This is expected to occur in mRNA. C. Exoribonuclease must have a mutation causing it to attack RNA. D. The strand must have been capped during replication.

A. The ends were not modified during processing.

Tiger sharks could be considered a keystone species because they _________. A. keep turtle populations under control, which protects sea grasses B. are at the highest trophic level of a food pyramid C. have little impact on other aquatic populations D. are able to adapt to most types of marine ecosystems

A. keep turtle populations under control, which protects sea grassesL

Using the codon wheel, which amino acid is coded for by the codon AUG? A. methionine B. tyrosine C. asparagine D. isoleucine

A. methionine

Individuals of the same species may be spread across an environment in different patterns. What level of biological organization is being represented by these patterns? A. population B. community C. cell D. biosphere

A. population

The table shows organisms that are part of a freshwater ecosystem. Which of the following organisms is part of the trophic level that has the least available energy? Freshwater Ecosystem Inhabitants Small fish Freshwater plants Great blue heron Frogs Phytoplankton A. Frog B. Great blue heron C. Phytoplanton D. Small fish

B. Great blue heron

Why must the mRNA strand be read in only one direction during translation? A. If the ribosome read the mRNA strand in a different direction, the protein would end up with Okazaki fragments. B. The codons would be different if read in the other direction, which would synthesize a different protein. C. The mRNA strand is read in different directions in different organisms. D. The stop codon would be read first if the mRNA strand was translated the opposite direction.

B. The codons would be different if read in the other direction, which would synthesize a different protein.

Species A and Species B live in a mutualistic relationship. What would most likely happen to Species B if a disease suddenly attacked and killed most of Species A? A. Species B would also get the disease. B. The population of Species B would decrease. C. The population of Species B would increase. D. There would be no effect on Species B.

B. The population of Species B would decrease.

Which of the following is NOT an example of an exotic species negatively impacting the environment? A. The species carries a disease that native organisms have never been exposed to. B. The species fills a niche that had not previously been filled. C. The species outcompetes the native organisms for food and space. D. The species disrupts the balance of a food web.

B. The species fills a niche that had not previously been filled.

Why might you find fewer photosynthetic organisms at deeper levels of an ocean? A. Photosynthetic organisms only float and cannot sink. B. The sun's rays cannot reach the deep ocean. C. Photosynthetic organisms cannot survive in cold water. D. Photosynthetic organisms cannot withstand extreme pressure.

B. The sun's rays cannot reach the deep ocean.

A mutation occurs that causes RNA polymerase to stop transcription before the end of the gene. What must the mutation have done? A. added a stop codon B. altered a terminator sequence C. altered a promoter D. chemically modified the end of the RNA

B. altered a terminator sequence

The steps of translation are: 1. Ribosomes read the mRNA sequence. 2. A ribosome attaches the amino acid to the protein chain with a peptide bond. 3. The ribosome reads a stop codon and detaches from mRNA. 4. Protein is released from the ribosome. Which step is missing from the process? A. The DNA strands unwind and separate. B. tRNA retrieves the amino acid associated with the anticodon. C. rRNA proofreads the growing protein for mutations. D. The RNA moves into the nucleus.

B. tRNA retrieves the amino acid associated with the anticodon.

Study the process shown in the diagram below. What is the final product of this process? A. DNA B. RNA C. A protein D. A carbohydrate

C. A protein

A mutation occurs in a section of mRNA that is processed out during RNA processing. What are the most likely effects of this mutation? A. It will probably be beneficial to the organism. B. It will probably be harmful to the organism. C. It will have no effect on the organism. D. There is no way of knowing how the organism will be affected.

C. It will have no effect on the organism.

The diagram shows a food web. Based on the diagram, which of the following is a producer? A. Frog B. Mayfly C. Phytoplankton D. Trout

C. Phytoplankton

Barnacles are often found attached to a whale's skin, causing no harm to the whale. If the barnacle and whale are commensalists, which of these bests describes the barnacle? A. The barnacle acts as a host for the parasitic whale. B. The barnacle is neither harmed nor benefited by its attachment to the whale. C. The barnacle benefits from its attachment to the whale. D. The barnacle provides a food source for the whale.

C. The barnacle benefits from its attachment to the whale.

In parts of Africa, gazelles and lions are part of the same community. Gazelles are a food source for lions. How would an increase in lion birth rates most likely affect the gazelles? A. The gazelle birth rate would also increase. B. The gazelle population would increase. C. The gazelle death rate would increase. D. Gazelles would not be affected.

C. The gazelle death rate would increase.

A molecular biologist identifies a unique sequence of DNA in people who have difficulty secreting tears and nasal mucus. Using a tool called BLAST (Basic Local Alignment Search Tool), the investigator compares the affected DNA to a reference sequence. Based on his results, he concludes that a point mutation has occurred in the DNA that codes for the antibody Immunoglobulin A. Which of the following conclusions is most likely supported by these data? A. The mutation led to the rearrangement of large portions of a chromosome. B. The mutation caused the reading frame of the entire sequence to shift. C. The mutation caused an incorrect amino acid to be synthesized. D. The mutation caused an incorrect amino acid to be synthesized.

C. The mutation caused an incorrect amino acid to be synthesized.

Several species of Asian carp have been introduced to freshwater areas in the United States, either intentionally or by accident. These carp typically eat plankton. The graph shows three species of Asian carp that were caught in sampling studies at a particular location along the Mississippi river. Based on the data shown, how are Asian carp populations likely affecting ecosystem stability in the region? A. They are likely stabilizing ecosystems by eliminating excess plankton. B. They are not likely to affect ecosystem stability because they eat plankton. C. They are likely changing population dynamics by competing with other plankton-eating species. D. They are likely to switch from plankton to other food sources, which will result in an overgrowth of plankton.

C. They are likely changing population dynamics by competing with other plankton-eating species.

How do earthworms help cycle matter through the ecosystem? A. They eat fecal matter so it does not block the producer growth. B. They eat carnivores so there is no "top of the food chain." C. They break down dead material, releasing nutrients for use again. D. They inhale carbon dioxide and release oxygen use for animals.

C. They break down dead material, releasing nutrients for use again.

Which of the following human activities might eventually result in secondary succession? A. Scuba diving is restricted near a coral reef. B. Fertilizer is added to a grassland to help the plants to grow. C. Volunteers plant trees in a forest ecosystem. D. A campfire is left unattended, and a forest fire breaks out.

D. A campfire is left unattended, and a forest fire breaks out.

Suppose the producers in a certain ecosystem are dying out because there is a lack of nutrients in the water and soil. What is the probable cause of the problem? A. There are too many carnivores in the ecosystem. B. The herbivore population is decreasing. C. The consumers are absorbing all of the available nutrients. D. Decomposers are not recycling nutrients for use.

D. Decomposers are not recycling nutrients for use.

Only about one-tenth of the energy available in one trophic level is passed on to the trophic level above it. Based on this information, why there are usually very few tertiary consumers in the food chain? A. Tertiary consumers do not need much energy to survive. B. Tertiary consumers are usually eaten by secondary consumers. C. Energy is passed directly from the producers to tertiary consumers. D. There is fierce competition for the energy that is available at the top of the food chain.

D. There is fierce competition for the energy that is available at the top of the food chain.

Mutations can be characterized according to the size of the region of DNA that they affect. Classify each type of mutation as either a small-scale mutation, a large-scale mutation, or possibly both of these. (A) Deletion (B) Loss of an allele (C) Translocation (D) Insertion (E) Amplification (F) Point mutation

Large-scale (B) Loss of an allele (C) Translocation (E) Amplification Small-scale (D) Insertion (F) Point mutation Both (A) Deletion

Mutations can arise from various changes to molecules. Connect the cause of a mutation with its mechanism. Tautomerism Depurination Deamination Slipped strand mispairing During replication the new DNA strand breaks, and resynthesis leads to insertions or deletions. A base's hydrogen bonding pattern changes, causing incorrect base pairing during replication. A base loses an amine group. The bases adenine or guanine are lost.

Tautomerism A base's hydrogen bonding pattern changes, causing incorrect base pairing during replication. Depurination The bases adenine or guanine are lost. Deamination A base loses an amine group. Slipped strand mispairing During replication the new DNA strand breaks, and resynthesis leads to insertions or deletions.

The cell relies on several types of RNA to carry out the process of translation. Connect the type of RNA with its function and/or structure. Each type of RNA will be paired with exactly two functions and/or structures. mRNA tRNA rRNA Connects a three-letter genetic code to a corresponding amino acid Helps to form peptide bonds between amino acids Carries genetic information from the nucleus to ribosomes Forms subunits on a ribosome to allow decoding of genetic information Transfers amino acids to the ribosome to build a protein A sequence of nucleotides that direct the assembly of amino acids into protein

mRNA Carries genetic information from the nucleus to ribosomes A sequence of nucleotides that direct the assembly of amino acids into protein tRNA Connects a three-letter genetic code to a corresponding amino acid Transfers amino acids to the ribosome to build a protein rRNA Helps to form peptide bonds between amino acids Forms subunits on a ribosome to allow decoding of genetic information