ch. 12
What is the primary role of DNA in a cell, and how does this role differ from that of RNA?
DNA stores genetic information for the cell, while RNA uses that information to help make proteins.
How does the process of transcription use DNA to produce RNA?Include where this process occurs in eukaryotic cells.
Transcription copies DNA into RNA and occurs in the nucleus of eukaryotic cells.
What is genetic engineering, and how does it differ from traditional selective breeding?
Genetic engineering is the direct change of an organism’s DNA in a lab, while selective breeding involves choosing parents with desired traits over many generations.
What is a genetically modified organism (GMO), and give one example.
A genetically modified organism (GMO) is an organism whose DNA has been changed, such as corn engineered to resist pests.
What is the human genome, and approximately how many genes does it contain?
The human genome is the complete set of DNA in a human, and it contains about 20,000 genes.
Describe the structural differences between DNA and RNA, including sugar type, nitrogenous bases, and strand structure.
DNA has deoxyribose sugar, thymine, and two strands, while RNA has ribose sugar, uracil, and one strand.
Why is RNA able to leave the nucleus while DNA remains inside?Relate your answer to structure and function.
RNA can leave the nucleus because it is smaller and single-stranded, while DNA stays inside for protection.
Describe how restriction enzymes are used in genetic engineering.
Restriction enzymes cut DNA at specific sequences so genes can be removed or inserted.
What are two potential benefits of genetic engineering in agriculture?
Two benefits of genetic engineering in agriculture are higher crop yields and resistance to pests or diseases.
Explain why humans share a large percentage of their DNA with other organisms, such as chimpanzees or mice.
Humans share a large percentage of DNA with other organisms because many genes control basic life functions and were inherited from common ancestors.
Why is thymine found in DNA while uracil is found in RNA? Explain one biological advantage of this difference.
Thymine makes DNA more stable than uracil, which helps protect genetic information long-term.
Explain how a mutation in DNA could affect the final protein produced, even though proteins are not made directly from DNA.
A mutation in DNA can change mRNA and amino acids, which can change the final protein.
What role do plasmids play in genetic engineering experiments involving bacteria?
Plasmids act as carriers that move foreign genes into bacteria.
What are two possible risks or ethical concerns associated with genetic engineering?
Two possible risks or ethical concerns are unintended effects on ecosystems and concerns about modifying living organisms.
What was the main goal of the Human Genome Project, and why was it important to science and medicine?
The main goal of the Human Genome Project was to identify and map all human genes, which helped scientists better understand diseases and develop medical treatments.
Explain how complementary base pairing works in DNA and why it is important for DNA replication.
Complementary base pairing means A pairs with T and C pairs with G, allowing DNA to copy itself accurately.
Describe one similarity and one difference between DNA replication and RNA transcription.
Both replication and transcription use DNA as a template, but replication makes DNA while transcription makes RNA.
Explain how recombinant DNA is created and why it is important.
Recombinant DNA is created by combining DNA from different organisms, and it is important because it allows scientists to give organisms new traits.
How does gene cloning differ from gene therapy?
Gene cloning makes copies of a gene, while gene therapy attempts to treat diseases by fixing or replacing faulty genes in people.
Explain how environmental factors can influence gene expression without changing the DNA sequence.
Environmental factors like diet, stress, or sunlight can turn genes on or off without changing the DNA sequence, a process called gene regulation.
Compare and contrast the three main types of RNA (mRNA, tRNA, rRNA) in terms of their functions in protein synthesis.
mRNA carries instructions, tRNA brings amino acids, and rRNA forms the ribosome where proteins are made.
Why is RNA considered less stable than DNA, and how does this instability relate to its function in the cell?
RNA is less stable because it is single-stranded, which fits its role as a temporary messenger in the cell.
How is genetic engineering used to produce human insulin, and why is this beneficial for people with diabetes?
Scientists insert the human insulin gene into bacteria so they produce insulin, which helps people with diabetes control their blood sugar.
Why is regulation important in genetic engineering research and applications?
Regulation is important to ensure genetic engineering is safe, ethical, and does not harm humans or the environment.
Why is studying the human genome important for understanding human evolution and diversity?
Studying the human genome helps scientists understand how humans evolved and why people have genetic differences such as skin color, height, and disease risk.