Ch. 8 Genetics** Flashcards
Gergor Mendel (5)
- green peas
- father of genetics
- principle of dominance
- principle of segregation
- principle of independent assortment
principle of dominance
Dominant And recessive
- States that when two factors for a trait were present in the offspring, the one that is expressed is described as dominance
- the other factor is referred to as recessive since at times it appeared to recede into the background or “skip” generations.
Factors
AKA as variations of a gene called alleles
-section on a chromosome
*** Principle of Segregation
States that ______ (alleles) are ______ from one another during the formation of ______.
Each ________=_______ member from the pair of alleles
States that genes (alleles) are segregated (separated) from one another during the formation of gametes. That each gametes receives only one member from the pair of alleles
Principle of Independent Assortment
States that during the process of segregation, the alleles are passed to the next generation independently (randomly) from one another
*** Allele
Designates a particular base pair sequence in a DNA strand. It can be thought of as a variation in the form of a gene relating to the same trait
- individual organism usually possesses only 2 alleles, one from each of the parents of that individual
- in diploid organisms an allele is found on each of the two homologous chromosomes
Homozygous
If the two alleles are identical
“Same”
homozygous dominant -AA
homozygous recessive- aa
Heterozygous
With one allele homologue and the different allele on the other homologue is called hybrid
“Different” or “Aa”
Doninant
If the appearance of a heterozygote is the same as that of a homozygote, then the allele common to both is considered to be dominant
Recessive
The alleles whose presence is not evident in the physical appearance
Genotype
The listing of the alleles of a gene present in an individual
Phenotype
The description of an individuals appearance
Punnett square
By R.C. Punnett
A grid system showing genotypes of parental gametes on the top and left side. The gametes are joined in the interal boxes (as fertilization) to result in the genotypes of possible offspring
Multiple Alleles
Series of several alleles controlling the same trait
Codominance
Both alleles presents in a heterozygote may show their effects simultaneously
Ex: Red & white flowers
= Red and White flower in one flower at once
Incomplete dominance
Of this were in effect, the same parents would produce pink offspring
Ex: red and white flowers = pink flower (mixed)
ABO blood types
Typify a multiple allele condition where codominance occurs
Erythrocytes
Red blood cells
Antibodies
Are substances produced by an organism to neutralize foreign bodies that are potentially harmful to the individual.
Antigens
Foreign substances that cause the formation of and/or react with antibodies
** Highlights and graphs
Page 107-108
Pedigree charts
Show inheritance patterns within a family and can be used to
• determine if a disorder is caused by a recessive, dominant, or sex link allele
• the likelihood that an offspring will have the disorder
Square= male Circle= female Dark=disorder
- disorder is recessive, dominant, or sex allele
- likelihood of getting disorder
Sex linked alleles
Are symbolized along with the chromosome on which they are located
*** Highlights
Pg. 112
