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.
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. D. The DNA would remain the same as before.
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. To determine this difference, you need to understand the basic structure of prokaryotic and eukaryotic cells. Prokaryotes, such as bacteria, lack a nucleus and their DNA is found in the cytoplasm. On the other hand, eukaryotes, including plants, animals, and fungi, have a nucleus where their DNA is stored. This distinction affects how gene regulation occurs in these two types of organisms.
2. The correct answer is D. The DNA would remain the same as before. To determine this, you need to understand the process of transcription and translation. During transcription, a gene's DNA sequence is copied into mRNA. The mRNA molecule will contain both exons, which code for the protein, and introns, which are non-coding regions. However, before translation, introns are removed from the mRNA molecule through a process called splicing. If a cell were to mistakenly transcribe and translate the intron sequence, it would not affect the DNA itself.
3. The correct answer is C. Operator. To determine this, you need to understand the process of gene regulation in prokaryotic cells. Prokaryotes regulate the expression of their genes through the binding of repressor proteins to specific DNA sequences called operators. The repressor protein prevents the transcription of the adjacent gene by blocking the binding of RNA polymerase to the promoter region.
4. The correct answer is A. RNA processing. To determine this, you need to understand the steps involved in gene expression in eukaryotic cells. After transcription, eukaryotic mRNA molecules undergo several modifications, including the removal of introns and the addition of a poly-A tail and a 5' cap. This process is known as RNA processing and occurs before the mature mRNA is transported out of the nucleus for translation.
5. The correct answer is C. The body plans of complex animals are very similar to one another. To determine this, you need to understand the role of Hox genes in controlling the development and body plans of multicellular animals. Hox genes are highly conserved across different animal species, meaning they are very similar in sequence and function. This similarity suggests that these genes play a crucial role in determining the basic body plan of complex animals and have been conserved throughout evolution.