Textbook Notes (363,534)
Canada (158,402)
Biology (309)
BIOL 239 (19)
All (1)

BIOL239 Set 1 Mendelian Genetics Notes.docx

4 Pages
Unlock Document

University of Waterloo
BIOL 239

BIOL239 Set 1 Mendelian Genetics (p40-48) Chp.3 Gregor Mendel  Laid the foundation for the study of genetics  His ideas were published in 1866 under the title “Experiments in Plant Hybridization”  His experiments on pea plants made it clear how traits are inherited The Garden Pea  Easily grown in experimental gardens or pots  Contains both male and female sex organs  The male sex organ is the anther which produce sperm-containing pollen  The female organ is the ovary which produces eggs  Pea reproduction is peculiar in that the flower petals close down tightly which prevent any pollen grains from entering or leaving the plant  Pea plants self fertalize because of this restriction of incoming and outgoing pollen grains  These pea plants are highly inbred and display very little genetic variation from one generation to the next. Because of this uniformity such strains are known as true-breeding Monohybrid Crossing - Mendel cross-fertilized tall and dwarf plants to investigate how height was inherited - He did this by removing anthers from one variety and apply the pollen to the stigma, a sticky organ that leads to the ovary - He found that no matter how these plants were crossed (dwarf female w/ tall male or dwarf male w/ tall female) the reciprocal crosses gave the same result - Although when he allowed the reciprocal crosses to undergo self fertilization and produce the progeny (progeny are the offspring) there were tall and dwarf plants in a 3:1 ratio. - Mendel called the latent factor (dwarf) recessive and the expressed factor (tall) dominant - Mendel did monohybrid crossing to study the inheritance of other plant characteristics as well and discovered that the progeny traits appeared in a 3:1 ratio - The factors are now known as genes and the dominant and recessive forms are known as alleles - Mendel observed that genes come in pairs, each parental strain that he used in his experiments carried two identical copies. In modern terminology these genes are diploid and homozygous (Homozygous refers to having identical alleles for a single trait. Ex. The gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). A homozygous plant would contain the following alleles for seed shape: (RR) or (rr).) - However during the production of gametes, Mendel proposed that the two copies are reduced to one and they carry only one copy of a gene, this is known as haploid - When crossing two genetically different plants the off
More Less

Related notes for BIOL 239

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.