Patterns of Inheritance- Genetics Flashcards
(38 cards)
Character?
A heritable feature (flower colour)
Trait?
A variant of each character (purple or white)
Gene?
The instructional area of DNA on a chromosome that codes for a certain inheritable trait. Ex. Gene for eye colour, hair colour, and height.
Allele?
Two or more alternate forms of a gene, symbolized by letters. Each allele is located on the same position (Gene) on one of the pair of homologous chromosomes. Ex. Alleles for colour are blue or brown.
Dominant?
Allele that masks the other allele
Recessive?
Allele that is covered up
Homozygous?
Having two of the same allele (AA or aa); true-breeding.
Heterozygous?
Having two different alleles (Aa).
Genotype?
All of the organisms alleles (genetic information)’ both expressed and hidden. Represented by letters. Ex. Bb, BB, bb
Phenotype?
The visible, physical trait of the organism? Ex. Brown eyes.
Cross pollination?
One plant fertilizes a different plant.
Self pollination?
A plant fertilizes itself.
True-Breeding (pure bred)?
Synonymous with homozygous; plants that over several generations only produce plants like themselves. Ex. AA or aa
Hybrid?
Synonymous with heterozygous; carries two different alleles of the same gene. Ex. Aa
Parent Generation?
First organisms to breed; represented by the letters P1.
FIlial Generation?
The offspring resulting from the parent (P1) generation; represented by the letters F1 (first filial). The offspring that result from the F1 generation (first filial) are represented as the F2 generation (second filial).
What are the two influences that determine what an organisms will be like?
Hereditary and Environment
What is genetics?
The science of heredity
Gregor Mendel did some of the earliest work studying hereditary. He chose to use pea plants for his work because:
1) Pea plants have contrasting pairs of the same trait (homologous genes).
2) Peas can easily be cross pollinated.
Although peas usually___, Mendel was able to see Rudy how traits were inherited by using a process called___.
Self pollination
Cross pollination
In the process of cross pollination that Mendel used,___grains from the___of one plant would be transferred to the___of another. (Pollen grains form the___nuclei, egg cells are found at the base of the___of the pea flower).
Pollen, stamen, egg cells, sperm, pistil
What did Mendel observe?
That peas allowed to self-pollinate would consistently produce offspring identical to the parent plant. He then experimented with cross pollination to see what the offspring of parents plants that varied on only one trait would look like.
When Mendel experimented with cross pollination to see what the offspring of parent plants that varied on only one trait would look like what did he find?
Tall plants X short plants yielded tall;
Yellow seeds X green seeds yielded yellow;
Round seeds X wrinkled seeds yielded round
After Mendel’s experimented with cross pollination and parents that varied in only one trait what he did he wonder?
What happened to the characteristic lost when plants with different traits were cross-pollinated.
