All flashcards
Flashcard 1: What is a major goal of selective breeding in crops?
Answer: Increase yield, quality, or resistance to pests and disease. Farmers select for traits that improve crop productivity and survival.
Flashcard 2: What is artificial selection?
Answer: Human-directed selection of traits, rather than natural selection. Humans choose which organisms reproduce, not environmental pressures.
Flashcard 3: What is hybridization in selective breeding?
Answer: Crossing different varieties to combine desirable traits. Mixing genetic material from different lines creates new combinations.
Flashcard 4: Which term describes breeding two different breeds to combine useful traits?
Answer: Crossbreeding. Mixing breeds combines complementary traits from each parent.
Flashcard 5: Which term describes breeding closely related organisms to keep desired traits?
Answer: Inbreeding. Mating relatives concentrates shared genes, including desired ones.
Flashcard 6: What is gene editing (for example, CRISPR) used for?
Answer: Making targeted DNA changes, such as adding, removing, or replacing genes. Allows precise modifications to specific DNA sequences.
Flashcard 7: What is a key difference between selective breeding and genetic engineering?
Answer: Breeding mixes existing genes; engineering directly alters DNA. Breeding works with natural genes; engineering adds new ones.
Flashcard 8: What is genetic variation, and why does selective breeding require it?
Answer: Differences in genes; it provides traits that can be selected. Without different alleles, there's nothing to select for.
Flashcard 9: What is heterosis (hybrid vigor)?
Answer: Hybrids show stronger growth or health than either parent line. Mixed genetics often produces healthier offspring than pure lines.
Flashcard 10: Identify the most likely outcome of repeatedly breeding only the fastest racehorses.
Answer: Average speed increases as speed-related alleles become more common. Selection for speed genes increases their proportion in offspring.
Flashcard 11: Identify the best explanation for why purebred lines may have more inherited disorders.
Answer: Reduced genetic diversity increases expression of harmful recessive alleles. Limited gene pool allows harmful alleles to pair up more often.
Flashcard 12: Identify the genetic technology most suited to turning off one specific gene in an organism.
Answer: Gene editing (such as CRISPR) targeted to that gene. CRISPR can precisely disable specific genes without adding new ones.
Flashcard 13: What is a common risk of inbreeding?
Answer: Higher chance of harmful recessive traits and genetic disorders. Related parents share more harmful alleles that can pair up.
Flashcard 14: What is inbreeding?
Answer: Breeding closely related individuals to increase trait uniformity. Mating relatives concentrates similar alleles in offspring.
Flashcard 15: What is a transgenic organism?
Answer: An organism with a gene inserted from a different species. Contains DNA from another species through genetic engineering.
Flashcard 16: What is a trait in genetics?
Answer: A characteristic influenced by genes and often by the environment. Observable features determined by genetics.
Flashcard 17: What does selective breeding change in a population over many generations?
Answer: It increases the frequency of alleles for chosen traits. Desired alleles become more common through selection.
Flashcard 18: Identify the main goal of selective breeding in crops or livestock.
Answer: To produce offspring with more desirable traits. Improves crops and livestock for human benefit.
Flashcard 19: What is a major risk of inbreeding for a population?
Answer: Reduced genetic diversity and increased chance of harmful traits. Less variation makes populations vulnerable to disease.
Flashcard 20: Identify the likely result if breeders select only the largest seeds for many generations.
Answer: Average seed size increases in the population. Selecting for a trait shifts the population toward it.
Flashcard 21: What is CRISPR most often used for in genetic technology?
Answer: Precisely editing DNA by cutting and altering specific sequences. A tool that cuts DNA at specific locations.
Flashcard 22: Identify the key difference between selective breeding and genetic engineering.
Answer: Breeding selects existing variation; engineering directly changes DNA. One works with natural variation, the other creates new genes.
Flashcard 23: What is heredity?
Answer: Passing genetic information and traits from parents to offspring. How traits are inherited through generations.
Flashcard 24: What is a gene?
Answer: A DNA segment that helps determine a trait. Basic unit of heredity that codes for traits.
Flashcard 25: Which term describes an organism that contains DNA from another species?
Answer: Transgenic organism. Foreign DNA is inserted to add new traits.
Flashcard 26: Identify the best explanation for why a GMO crop can resist insects.
Answer: It contains a gene that produces an insect-killing protein. The inserted gene codes for a toxin harmful to insects.
Flashcard 27: Which outcome is most likely when a population is genetically uniform due to inbreeding?
Answer: Greater vulnerability to disease or environmental change. Low genetic diversity means fewer defenses against threats.
Flashcard 28: Identify the correct statement about gene editing versus selective breeding for speed of change.
Answer: Gene editing can change traits in one generation; breeding takes many. Direct DNA modification is immediate; breeding requires generations.
Flashcard 29: What is one major risk of inbreeding for a population?
Answer: Increased chance of harmful recessive traits appearing. Related parents share more harmful recessive alleles.
Flashcard 30: What is the main goal of selective breeding in plants or animals?
Answer: To produce offspring with specific desired traits more often. Breeders select parents with desired traits to pass them on.