Podcast
Questions and Answers
Stabilizing selection is most likely to occur in environments that are:
Stabilizing selection is most likely to occur in environments that are:
- Relatively constant and predictable over long periods of time. (correct)
- Undergoing rapid and drastic changes, favoring new adaptations.
- Characterized by high levels of pollution and disturbance.
- Experiencing frequent introduction of invasive species.
Which of the following scenarios exemplifies stabilizing selection?
Which of the following scenarios exemplifies stabilizing selection?
- A population of birds gradually developing larger beaks to crack harder nuts due to a drought.
- The increasing prevalence of antibiotic-resistant bacteria in hospitals.
- Human infant birth weights clustering around an intermediate weight, with higher mortality for very small and very large babies. (correct)
- A moth population shifting from predominantly light-colored to dark-colored during the industrial revolution.
What is a key difference between natural selection and artificial selection?
What is a key difference between natural selection and artificial selection?
- Natural selection leads to greater biodiversity, while artificial selection reduces it.
- Artificial selection relies on environmental pressures, while natural selection is driven by human intervention.
- Natural selection is a faster process than artificial selection.
- Artificial selection is driven by human choices, while natural selection is driven by environmental factors. (correct)
A farmer selectively breeds cows that produce high milk yields. Over several generations, what is the most likely outcome?
A farmer selectively breeds cows that produce high milk yields. Over several generations, what is the most likely outcome?
One potential drawback of artificial selection is:
One potential drawback of artificial selection is:
What is the primary purpose of using restriction enzymes in genetic engineering?
What is the primary purpose of using restriction enzymes in genetic engineering?
Following the cutting of both human DNA and plasmids with restriction enzymes, what is the role of DNA ligase?
Following the cutting of both human DNA and plasmids with restriction enzymes, what is the role of DNA ligase?
Which of the following is NOT a typical step in producing insulin using genetically modified bacteria?
Which of the following is NOT a typical step in producing insulin using genetically modified bacteria?
What is a recombinant plasmid?
What is a recombinant plasmid?
What is the primary benefit of using genetically modified bacteria to produce human insulin compared to extracting it from animal pancreases?
What is the primary benefit of using genetically modified bacteria to produce human insulin compared to extracting it from animal pancreases?
What is the main advantage of genetically engineering crops to be herbicide-resistant?
What is the main advantage of genetically engineering crops to be herbicide-resistant?
Bt toxin, used in genetically modified crops, provides what benefit?
Bt toxin, used in genetically modified crops, provides what benefit?
Which of the following describes genetic engineering?
Which of the following describes genetic engineering?
Which of these situations describes artificial selection?
Which of these situations describes artificial selection?
Which of the following is a potential environmental benefit of using genetically modified crops?
Which of the following is a potential environmental benefit of using genetically modified crops?
Flashcards
Stabilizing Selection
Stabilizing Selection
Natural selection favoring the most common phenotype in a stable environment, reducing variation.
Artificial Selection
Artificial Selection
A method where humans select parent organisms with desirable traits to breed.
Artificial vs. Natural Selection
Artificial vs. Natural Selection
Both can change trait distribution; artificial selection is human-driven, natural selection is environment-driven.
Genetic Engineering
Genetic Engineering
Signup and view all the flashcards
Genetic Engineering and Insulin
Genetic Engineering and Insulin
Signup and view all the flashcards
Restriction Enzymes
Restriction Enzymes
Signup and view all the flashcards
Plasmids
Plasmids
Signup and view all the flashcards
Recombinant Plasmid
Recombinant Plasmid
Signup and view all the flashcards
DNA Ligase
DNA Ligase
Signup and view all the flashcards
Genetically Modified Crops
Genetically Modified Crops
Signup and view all the flashcards
Herbicide Resistance
Herbicide Resistance
Signup and view all the flashcards
Pest Resistance
Pest Resistance
Signup and view all the flashcards
Bt Toxin
Bt Toxin
Signup and view all the flashcards
Gene Removal And Insertion
Gene Removal And Insertion
Signup and view all the flashcards
Genetically Modified Rice
Genetically Modified Rice
Signup and view all the flashcards
Study Notes
- These notes cover stabilizing selection, artificial selection, genetic engineering including genetically modified bacteria and genetically modified crops
Stabilizing Selection
- It is a type of natural selection where the fittest individuals in a stable environment survive and reproduce
- Individuals less adapted to new conditions are less likely to reproduce
- Favors common phenotypes and selects against less common ones
- It maintains the status quo in a population, especially in environments with constant conditions
Artificial Selection
- Also known as selective breeding, it is a process where humans select specific parent organisms with desirable traits and breed them to increase the chances of those traits being inherited
- Repeating this process over generations increases the number of offspring with desired traits
- It leads to changes in a population's adaptive features over generations
- It is caused by human intervention
- Characteristics selected by humans may not always suit an organism's adaptation to its natural environment
- Over many generations, prioritizing a single variety can reduce biodiversity, destabilizing the ecosystem
Genetic Engineering
- Genetic engineering involves altering an organism's genetic material by removing, changing, or inserting genes or DNA fragments
- Scientists can insert a gene from one organism into another's genetic material
- The inserted gene can instruct the new organism's cells to produce the same protein or polypeptide as the original organism
Genetically Modified (GM) Bacteria for Insulin Production
- Most insulin for type I diabetes is produced using genetically engineered bacteria
- GM bacteria eliminate the need to kill animals for insulin and allow for large-scale production
- The process includes these steps:
- Isolate the insulin gene by cutting DNA from human cells using restriction enzymes, which create "sticky ends"
- Identify and select the DNA fragments containing the insulin gene
- Introduce the insulin gene into bacteria using plasmids
- Cut plasmids with the same restriction enzyme to create complementary sticky ends
- Mix human DNA fragments with cut plasmids so sticky ends pair up
- Use DNA ligase to link the human DNA to the bacterial plasmid, forming a recombinant plasmid
- Add recombinant plasmids to a bacterial culture
- Select bacteria that have taken up the recombinant plasmids
- Place selected bacteria in fermenters under optimal conditions for reproduction
- Extract and purify insulin produced by the large bacterial population
Genetically Modified Crops
- Genetic engineering is used to produce crops with desired traits like herbicide and pest resistance.
- Herbicide-resistant and pest-resistant plants can increase crop yields while reducing the use of harmful chemicals
- Soya and maize plants are genetically modified to resist glyphosate, a common herbicide
- Some crop plants are modified with a gene that codes for an enzyme that breaks down glyphosate, protecting them from harm when the herbicide is sprayed
- Maize plants can be genetically modified to carry pest resistance genes, like the Bt toxin gene from bacteria, to resist insect attacks
- Rice plants are genetically modified to produce a precursor of vitamin A in their edible parts
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Notes covering stabilizing selection where the fittest individuals in a stable environment survive and reproduce. Includes artificial selection where humans breed organisms for specific traits. Also covers genetic engineering including modified bacteria and crops.
