Cellular Basis Flashcards
Principles of inheritance in animals
Animal genetics
Application of genetic principles in the
improvement of livestock and poultry.
Animal breeding
Modes of Inheritance– predict progeny phenotypic
distribution based on parental genotypes.
Qualitative genetics
Assessing genetic merit – describe traits with statistics to predict next record, genetic merit, response to selection.
Quantitative genetics
Gene and genotypic frequencies– predict direction
and magnitude of changes in a population
Population genetics
Observed expression of a trait
Phenotype
Composite of all genes that influence a trait
Genotype
All non-genetic factors that influence a trait
Environment
A packet of coiled up DNA
Chromosomes
Where are chromosomes located
In the nucleus of cells
A typical chromosome is about _____ mm long
0.004 mm
How long is the DNA
About 4cm long
Chromosome # of cat
38
Chromosome # of chicken
78
Chromosome # of cattle
60
Chromosome # of dog
78
Chromosome it of donkey
62
Chromosome # of goat
60
Chromosome # of horse
64
Chromosome # of humans
46
Chromosome # of pig
38
Chromosome # of sheep
54
Two strands that wrap around each
other to resemble a twisted ladder
whose sides made of sugar and
phosphate molecules
DNA molecule
Connected by rings of nitrogen-containing chemicals called bases
DNA molecule
Four bases of DNA
Purine:
Pyridine:
Purine bases:
- adenine and guanine
- two carbon rings
Pyrimidine bases:
- thymine andcytosine
- single carbon ring
The basic physical and functional units of heredity
Gene
Protein coding sequence
Exon
Intervening sequence
Intron
Describes how nucleotide sequence is converted to protein sequence
Genetic code
Unit of three nucleotides
Codon
How many codons can the four bases form?
64
__ Amino acids are found from the nature
20
Changes in DNA that affect genetic information
Gene mutations
Changes in one or a few nucleotides
Point mutation
shifts the reading frame of the genetic message so that the protein may not be able to perform its function
Frameshift mutations
Sex chromosome abnormalities
Klinefelter’s syndrome
XYY syndrome
Turner’s syndrome
XXX
- Male
- sterility
- small testicles
- breast enlargement
Klinefelter’ s syndrome
- Normal male traits
- Often tall and thin
- associated with antisocial and behavioral problems
XYY syndrome
- X0
- Female
- Sex organs don’t mature at adolescence
- Sterility
- short stature
Turner’s syndrome
- trisomy x
- female
- little or no visible differences
- tall stature
- learning disabilities
- limited fertility
XXX
First person to study genetics
Gregor Mendel
Responsible for the laws governing inheritance of traits
Gregor Mendel
Mendel’s 3 laws
Law of dominance
Law of segregation
Law of independent assortment
States that on crossing homozygous organisms for single pair of contrasting characters, only one character make its appearance in F1 generation and is named as Dominant character
Law of dominance
In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation
Law of dominance
All the offspring will be heterozygous and express only the dominant trait
Law of dominance
During the formation of gametes (eggs or sperm), the two alleles responsible for a trait separate from each other
Law of segregation
Alleles for a trait are then “recombined” at fertilization, producing the genotype for the traits of the offspring
Law of segregation
also known as “Inheritance Law”, states that alleles of different genes assort independently of one another during gamete formation
Law of independent assortment
Different traits are inherited independently of each other, so that there is no relation, for example, between a cat’s color and tail length
Law of independent assortment
One gene does not hide or mask the effect of the other gene in gene pair = results in mixture of the two traits
Incomplete dominance
Two alleles are expressed in heterozygous individuals
Codominance
Interaction of two or more pair of genes that are not alleles to produce a phenotype that they don’t produce when they occur seperately
Epistasis
Contains the genetic code
DNA
Joins the bases together
Hydrogen bond
Nucleotides are joined with what bond
Phosphodiester
Alternate versions of DNA
Alleles
There may be more than two alternative genes than can occupy the Lous
Multiple alleles
Occurs when there is an additive effect from two or more genes
Polygenetic inheritance
Pigmentation in humans is controlled by at least __ separately inherited genes
3
