Exam 3 - Lecture 8 - Inheritance, Genes, & Chromosomes Flashcards
What is blending inheritance theory?
Progeny will be an intermediate blend of both parents because the gametes fuse and blend into one
What is particulate inheritance theory?
Progeny acquire physically distinct genetic determinants that remain intact and distinct after gamete fusion
Which inheritance theory did Mendel’s data support?
Particulate inheritance theory
What are “characters”?
Observable physical features
Ex: plant height, seed, shape, flower color
What are traits?
Physical expression of different characters
(Ex:
short vs. tall,
round seeds vs. wrinkled seeds,
pink flowers vs white flowers, etc.)
What are true breeding plants?
Plants whose traits remain intact when they self-pollinate
What is a hybrid?
Plant that is produced when crossing two parents with different traits
What is a monohybrid cross?
When two parental plants with a single differing trait “breed”
What is a dominant trait?
Trait that manifests in the F1 progeny and is abundant in the F2 generation
What is a recessive trait?
Trait that is absent in the F1 progeny and less abundant in the F2 generation
What are alleles?
Variants of a gene
What is the law of segregation?
States that during gametogenesis in diploid organism, two copies of a gene separate and a copy goes to each gamete
What is the predicted outcome of a monohybrid cross if the cross is between 2 heterozygous F1 progeny?
For the F2 generation:
1/4 will be homozygous dominant
2/4 will be heterozygous
1/4 will be homozygous recessive
Genotype ratio is 1:2:1
Phenotype ratio is 3:1
What is a dihybrid cross?
When plants with two differing traits are bred
Ex: one plant produced green and wrinkled seeds and the other produces smooth and yellow seeds
What will the F1 progeny of a dihybrid cross look like when one parent is homozygous dominant and the other is homozygous recessive?
They will be heterozygous at two loci
