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Chapter 14 & 15 - Coggle Diagram
Chapter 14 & 15
15 Chromosomal Basis of Inheritance
Chromosomes theory
Established by Sutton and Boveri established a chromosome based of mendels genetic theory
Genetic Mapping
Linkage Map
based on how much it recombines
Uses units to measure this frequency
Morgan Hunt research on fruit flies
Good to study due to the flies breeding a lot, every 2 weeks in frequency, and have four pairs of chromosomes
documented the common type which was black
Documented a mutant type which had red eyes
Paired mutant males and normal females
F2 Generation has a 3:1 Ratio, only males having red eyes
F1 generation had all red eyes
Discovery the XX for female chromosomes and XY for male chromosomes
Use XX and XY because they are a sex linked trait
The chromosomal basis of sex
Mammals have a large X chromosome and a smaller Y chromosome
Sex Linked Genes
These genes are only passed on the X (X-Linked) chromosome or the Y (Y-Linked) chromosome
X pattern of inherence recessive
a female needs 2 of the same genes to be expressed
Colorblindness is an example
Only needs one X working during pregnancy, the inactive X turns into a Barr body
Pattern of Y inherence recessive
Only needs one gene to be expressed
Genes on the same chromosome are sex Linked genes
Genetic recombination
the offspring has traits differing from the parents
Called crossing over
Happens when the genes are touching each other, swapping genetic material
Non Disjunction
happens with irregular separation in mitosis
trisomatic
A zygote with three copies of a chromosome
Mono-somatic
A zygote with only one chromosome
Polyploidy
has more than two complete sets of chromosomes
Aneuploidy
Occurs during Non Disjunction has happened
14 Mendel & the Gene Idea
He was the Father of genetic inheritance
He looked at the character of his pea plants
This is the color of the pea plant
He also studied traits
These are the variety of colors in the plant
He studied pea plants analyzing why when cross breeding the plants
Recessive traits
Recessive traits are the non dominant trait, defined by lowercase letters
Two recessive traits must be present to allow the characteristic to be shown
Dominant traits
These traits show on the plant whether all the alleles were both dominant, which is Homozygous or Mixed which is Heterozygous Expressed as AA or Aa
Homozygous
The term that describes 2 of the same alleles
heterozygous
This term describes two different alleles
These are not true Breeding
Alleles
The versions of Genes expressed in letters, AA or Aa
Uppercase letters stand for Dominate traits, Lowercase letters are for recessive genes
Two alleles that separate can have an extra or missing one chromosomes
Levels of Dominance
Complete dominance
when the dominate trait is always expressed
Co-Dominance
express both traits at the same time
Incomplete dominance
Shares the traits, not fully covered by the dominate trait
Punnet square
The crossing and possibilities that could happen from breeding
Dihybrids
The Crossing of two characters, both will be heterozygous
Dihybrid Cross
This determines if the characters will be passed on as together or only one at a. time
Phenotype
The appearance of the dominate trait
Genotype
The genetic makeup, incudes dominate and recessive alleles
Hybridization
called the "True Breeding process", crossing the purple pea plant and the white pea plant
The parents are the starting breeding, indicated by P
The offspring of true breeding is called F1
The second generation is defined by F2 when its pollinated by the plant or self pollinate
Law of Segregation
Is the blending hypothesis
This hypothesis was wrong as the dominate trait was shining through
defined the product as the inheritable factor, is now called a gene
Mendels Model
He described inheritance of all off the offspring
Law of Independent assortment
follows a single character
Monohybrids
heterozygous for one character
Monohybrid cross
cross between heterozygotes