Lecture 12 Flashcards
What controls inheritance
Chromosomes
Name the basis of plant breeding
Mendel’s Laws
How are sexually reproducing plants pollinated
•Self Pollinated
•Cross Pollinated
What are the main steps of breeding
•Collection
•selection
•crossing
•evaluation
•introduction
What does Gene Transformation allow
Transfer of one or several genes
How does reproduction occur in plants
Via Seeds
Where is the chromosome located
Nucleus
What do genes determine
Metabolic activities of the cell
What are genes composed of
Nucleotides
Who’s sequence dictates the sequence of amino acids during protein synthesis
What are chromosomes made of
DNA
What is meiosis
cell division that reduces the genetic content by HALF
Why is meiosis necessary
to enable sexual reproduction (50% of each parent)
What are different forms of a gene called
Alleles
What 3 factors is Mandelian Genetics law of inheritance based on
•Genetic characters are controlled by two alleles
•One allele determines the phenotype observed for that trait
•One of the chromosomes from the parent will be passed on randomly to each of the gametes
Explain Qualitative traits
–Easily separated into distinct classes
–Controlled by one or few genes
–E.g., green or yellow pods in pea plants
Explain Quantitative traits
–Not easily separated into classes
–Controlled by many genes
–E.g., height and growth rate
Explain breeding in self pollinated plants
–Usually homozygous
–Common methods of breeding include pedigree selection or mass selection - wheat etc
Explain breeding in cross pollinated plants
–Heterozygous
–Can use mass selection
–Hybridization most commonly used
Explain Breeding by Pedigree Selection
•Seed from F1 generation is planted; superior plants are selected
•Seed from selected plants will be collected and planted in rows; undesirable plants discarded
•Additional selection within rows occurs with additional planting of selected seed as many as six times, to the F6 generation
•At the F6 generation, plant rows become uniform, and seeds from selected rows can be bulked and evaluated in yield trials
Explain Breeding by Hybridisation
•Corn inbreds developed by self-pollinating selected corn plants for several generations to make a uniform variety
•Corn hybrid produced by crossing two inbred plants with distinct genetic traits
•This first hybrid produced, an F1 hybrid, typically has traits superior to those of either inbred parent - hybrid vigour / heterosis
What is Genotype
The total genetic makeup
What is Phenotype
due to genotype, the environment, and their interaction
What is Heritability
proportion of phenotype controlled by genetic factors
For Genetic transformation what does transfer occur via
•Bacterium
•Gene gun
What is genetic transformation used for
qualitative traits like herbicide and disease resistance - GMO Crops
A crop with more than one transgenic trait is called what
Stacked trait variety
Benefits of genetically modified plants
•Crops’ resistance to pests
•Herbicide tolerance
•Adaptation to environmental stresses
•Desirable functional characteristics
•Desirable nutritional characteristics
Concerns of Genetically modified plants
•Safety of genetically modified plants
•Impact on human health
•Outcrossing with weedy relatives
•Unintended effects on nontarget organisms
•Resistant pests
•Ethical and religious issues
