Chapter 17 Flashcards
(30 cards)
What does inheritance mean?
The transmission of characteristics from parent to offspring.
particulate inheritance:
The idea that the determinants of hereditary traits are transmitted in discrete units, or particles, from one generation to the next.
hybridization:
The process in which two individuals of the same species with different characteristics are bred or crossed to each other; the offspring are referred to as hybrids.
What is a character in relation to Mendel’s experiments?
A characteristic of an organism, such as the appearance of seeds, pods, flowers, or stems in the garden pea.
What is a trait?
An identifiable characteristic; usually refers to a variant.
flower color is character, purple flowers is trait
What is a monohybrid?
The F1 offspring, also called single-trait hybrids, of true-breeding parents that differ with regard to a single character.
What is an allele?
A variant form of a gene.
What is a dominant trait?
Refers to the trait that is displayed in a heterozygote.
What is a recessive trait?
Refers to a trait that is masked by the presence of a dominant trait in a heterozygote.
What is a gene?
A unit of heredity. At the molecular level, a gene is an organized unit of base sequences in a DNA strand that can transcribed into RNA and ultimately results in the formation of a functional product.
What is Mendel’s law of segregation?
The two alleles of a gene separate (segregate) from each other during the process that gives rise to gametes, so every gamete receives only one allele.
What does genotype mean?
The genetic composition of an individual.
What does it mean for an individual to be homozygous?
An individual with two identical copies of an allele.
What does it mean for an individual to be heterozygous?
An individual with two different alleles of the same gene.
What does phenotype mean?
The characteristics of an organism that are the result of the expression of its genes.
Steps of creating a Punnett square?
Step 1: Write down the genotypes of both parents
Step 2: Write down the possible gametes that each parent can make
Step 3: Create an empty Punnett square
Step 4: Combine the alleles of the gametes in the empty boxes
Step 5: Determine ratios
What is a testcross?
A cross to determine if an individual with a dominant phenotype is a homozygote or a heterozygote.
dihybrid:
Refers to an offspring that is a hybrid with respect to two traits.
Mendel’s law of independent assortment:
The alleles of different genes assort independently of each other during the process that gives rise to gametes.
What is an X-linked gene?
A gene found on the X chromosome but not on the Y.
What are sex-linked genes?
A gene that is found on one sex chromosome but not on the other.
hemizygous:
Having only one copy of a particular gene; a male mammal is hemizygous for an X-linked gene.
wild-type allele:
A prevalent allele in a population.
mutant allele:
An allele that has been altered by mutation.
