Danielle 3

# Danielle 3 - Homework Required Problems 2.4 2.5 2.9 2.10...

This preview shows pages 1–8. Sign up to view the full content.

Homework Required Problems 2.4, 2.5, 2.9, 2.10, 2.12, 2.13, 2.15, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 3.10, 3.11, 3.17, 3.19, 3.22, 3.24, 3.27. Three problems from me in assignment to be posted.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Fig 3.1 Let D = tall Let d = dwarf P F1 F2 D_ = DD or Dd homozygous or heterozygous DD dd Dd 787 Tall (D_ ) 277 Dwarf (dd) •Mendel’s Peas •Parent shorts look exactly like F2 shorts •Recessive trait!! Wasn’t observed in the F1 generation •Saw that each plant had 2 “genes” or factors that controlled each trait
Mendel’s Initial Observations from Monohybrid Cross The dwarf trait is hidden in the F1, but reappears unchanged in the F2. This contradicts “blending inheritance”. In the F2, tall and dwarf plants appear in a ratio of about 3 tall : 1 dwarf . Individual traits don’t blend together Traits can “pass through” the F1 generation and appear unchanged in F2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Mendel’s Conclusions Each trait is controlled by an inherited factor, now called a “gene”. Two copies of each gene are present in the organism. These copies are called “alleles”. The alleles are usually transmitted unchanged through crosses. Mendel didn’t come across any mutations in his experiments Knew there were 2 copies of each gene because some traits didn’t appear until F2 generation
Fig. 3.2. Symbolic representation of Mendel’s cross Punnett Square Punnett Square is a device for multiplying probabilities Symbolic representation of the cross between tall and dwarf peas and a summary of the phenotypic and genotypic results

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Mendel’s Principles Principle of Dominance : In a heterozygote, one allele may conceal another. Principle of Segregation : In a heterozygote, the 2 alleles of the same gene segregate from each other during gamete formation. KEY POINTS Mendel studies the inheritance of 7 different traits in garden peas, each trait being controlled by a different gene Mendel’s research led him to formulate 3 principles of inheritance 1. The alleles of a gene are either dominant or recessive 2. Different alleles of a gene segregate from each other during the formation of gametes 3. The alleles of different genes assort independently
Molecular basis of Mendel’s cross Gibberellin (GA) is a plant growth hormone, synthesized by specific enzymes. Dwarf plants (dd homozygotes) have a

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/30/2008 for the course BIOL 2156 taught by Professor Larkin during the Spring '08 term at LSU.

### Page1 / 35

Danielle 3 - Homework Required Problems 2.4 2.5 2.9 2.10...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online