Plant Genetics and Breeding Flashcards
6 cards from real Agronomy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Plant Genetics and Breeding flashcards as text
What is the primary goal of marker-assisted selection (MAS) in plant breeding?
Answer: To use DNA markers linked to traits for faster, more accurate selection
MAS uses molecular markers associated with desired traits to select superior plants without waiting for phenotypic expression, speeding up breeding cycles.
Polyploidy in plants refers to what condition?
Answer: Having more than two complete sets of chromosomes
Polyploidy is the condition of having three or more complete sets of chromosomes; it is common in many important crop plants like wheat and cotton.
Which trait in Bt corn was introduced through genetic engineering?
Answer: Insect resistance via Bacillus thuringiensis toxin
Bt corn contains a gene from the soil bacterium Bacillus thuringiensis that produces proteins toxic to specific insect pests like European corn borer.
What does heritability (h²) measure in a plant breeding context?
Answer: The proportion of total phenotypic variation due to genetic variation
Heritability estimates the fraction of observed variation in a trait that is attributable to genetic differences rather than environmental factors.
What is the purpose of a testcross in plant breeding evaluation?
Answer: To evaluate the general combining ability of inbred lines using a common tester
Testcrossing inbred lines to a common tester allows breeders to assess their combining ability and predict hybrid performance.
Open-pollinated varieties differ from hybrid varieties primarily because they do what?
Answer: Breed true from saved seed and maintain genetic consistency
Open-pollinated varieties are genetically stable populations that breed true when seed is saved and replanted, unlike hybrids which segregate in F2.