1. What is one difference between gene regulation in prokaryotes and eukaryotes?
A. Prokaryotes remove exons from mRNA before translation while eukaryotes translate the entire sequence of mRNA.
B. All eukaryotes use operons to organiz
C. Prokaryotes do not store their genes in a nucleus like eukaryotes do.
D. Eukaryotes transcribe genes in response to environmental stimuli while prokaryotes transcribe genes randomly.
2. What would happen if a cell transcribed and translated a gene’s intron by mistake?
A. Additional amino acids would be inserted into the chain
B. The intron would begin to duplicate itself.
C. Errors in the protein folding would be repaired.
D. The DNA would remain the same as before.
3. In prokaryotic cells, repressor proteins bind to a section of DNA called a/an
A. Promoter
B. Chromatin
C. Operator
D. Repressor
4. The removal of sections of RNA, called introns, occur at which regulation step in eukaryotic cells?
A. RNA processing
B. post-translation
C. mRNA life span
D. chromatin remodeling
5. Question Hox genes are regulatory genes in multicellular animals that code for transcription factors that determine the basic body plan in a developing embryo. They act as switches that turn other genes on and off. Scientists have found that a mutation in a fruit fly hox gene produces flies with legs instead of antennae sticking out of their heads. Another hox gene mutation results in fruit flies with two pairs of wings instead of one pair. Hox genes affect body plans by controlling the expression of many other genes. Many multicellular animals have the same hox genes. Which statement is evidence for this claim?
A. There is a wide variety of body plans in complex animals.
B. The body plans of complex animals change over generations.
C. The body plans of complex animals are very similar to one another.
D. The body plans of complex animals typically have a large number of mutations.
please answer all
1. C. Prokaryotes do not store their genes in a nucleus like eukaryotes do.
2. A. Additional amino acids would be inserted into the chain.
3. C. Operator.
4. A. RNA processing.
5. C. The body plans of complex animals are very similar to one another.
1. C. Prokaryotes do not store their genes in a nucleus like eukaryotes do.
2. A. Additional amino acids would be inserted into the chain.
3. C. Operator.
4. A. RNA processing.
5. C. The body plans of complex animals are very similar to one another.
1. The correct answer is C. Prokaryotes do not store their genes in a nucleus like eukaryotes do. Prokaryotes have their genetic material, DNA, located in the cytoplasm, in a region called the nucleoid, while eukaryotes have their DNA stored within a nucleus surrounded by a nuclear membrane.
To arrive at this answer, you can compare and contrast the characteristics of prokaryotes and eukaryotes:
- Prokaryotes are simple, single-celled organisms without a nucleus, while eukaryotes are more complex, multicellular organisms with a nucleus.
- Prokaryotes have a circular DNA molecule while eukaryotes have linear chromosomes.
- Prokaryotes do not have introns in their genes, while eukaryotic genes often contain introns.
2. The correct answer is D. The DNA would remain the same as before. In eukaryotes, transcription of a gene produces a pre-mRNA molecule, which undergoes RNA processing to remove the introns and join the exons together. Only the exons are translated into a protein. If a mistake occurred and the cell transcribed and translated an intron, it would not affect the DNA sequence itself.
To arrive at this answer, you can understand the process of gene expression and the role of introns:
- Transcription is the process of copying DNA into RNA. During this process, the entire gene sequence, including introns, is transcribed into pre-mRNA.
- RNA processing then occurs, which involves removing the introns and joining the exons together to produce mature mRNA that can be translated into a protein.
- Translation is the process of synthesizing a protein using the information on the mRNA.
3. The correct answer is C. Operator. In prokaryotic cells, repressor proteins bind to a section of DNA called an operator. The operator is located near the promoter region, which is where RNA polymerase binds to initiate transcription.
To arrive at this answer, you can understand the components of prokaryotic gene regulation:
- Promoter: the DNA sequence where RNA polymerase binds to initiate transcription.
- Operator: the DNA sequence where regulatory proteins, like repressor proteins, bind to control gene expression.
- Repressor: a regulatory protein that can bind to the operator and prevent transcription of the gene.
4. The correct answer is A. RNA processing. In eukaryotic cells, the removal of introns from the pre-mRNA molecule occurs during RNA processing. After transcription, the pre-mRNA undergoes modifications, including the removal of introns and the addition of a protective cap and a poly-A tail. The spliced mRNA molecule is then ready for translation into a protein.
To arrive at this answer, you can understand the steps involved in gene expression in eukaryotes:
- Transcription: the process of copying DNA into pre-mRNA.
- RNA processing: modifications to the pre-mRNA, including the removal of introns and addition of a cap and poly-A tail.
- Translation: the process of synthesizing a protein using the information on the mRNA molecule.
5. The correct answer is C. The body plans of complex animals are very similar to one another. Hox genes are regulatory genes that control the development of body structures in multicellular animals. They determine the basic body plan in a developing embryo by turning other genes on and off. The fact that many multicellular animals have the same hox genes is evidence for the claim that body plans of complex animals are very similar to one another.
To arrive at this answer, you can make the following observations:
- Hox genes are highly conserved across different animal species, meaning they have been preserved in their structure and function throughout evolution.
- Animals with similar body plans, such as a head, abdomen, and segmented body, often share similar hox genes.
- Mutations in hox genes can lead to changes in the body plan, as seen in the example of fruit flies developing legs instead of antennae or having two pairs of wings.
Remember, when answering these questions, it is important to understand the concepts and processes involved in gene regulation and molecular biology. Taking the time to analyze the options and compare them to your knowledge will help you arrive at the correct answer.