GENETICS AND LIVESTOCK IMPROVEMENT Flashcards
the branch of biology that deals with the principles of heredity and variation in all living things
genetics
important contributors to the field of genetics
- gregor mendel (1866)
- hugo de vries 1901
- carl correns 1901
- erick von tshermark 1901
- william bateson (1906)
- johannsen (1909)
- james watson (1956)
- francis erick (1956)
father of genetics;
austrian monk who conducted breeding experiments on garden peas (pisum sativum L.);
formulated his hyphothesis about inheritance of characteristics in plants;
discovered that heriditary characteristics were determined by elementary factors (called GENES)
gregor mendel (1866)
independenty rediscovered the works of mendel in 1901
hugo de vries (netherlands)
carl correns (germany)
erick von tshermark (austria)
english biologist, studies inheritance of certain characteristics of the chicken;
showed that the mendelian laws applied also in animals
william bateson (1906)
danish biologist, coned the term GENE to refers to the particulate factor that mendel hyphothesized as the basic unit of inheritance
Johannsen (1909)
two young scientists of cambridge, university of england;
hyphotesized by the chemical nature and function of the gene w/c is now iniversally accepted
james watson and francis crick (1956)
improvement with the performance of the animals brought about by selection assuming that the environment is favorable
genetic improvement
primary genetic material of all cells;
biochemical compound consisting of chain of nucleotides
DNA deoxyribonucleic acid
chain of nucleotides;
each nucleotides consists of phosphate (P), sugar (S) and base (B)
polynucleotide
threadlike structures found in the nuclei of the cell
chromosome
the building blocks of proteins;
specific combinations of 3 bases;
20 of w/c are normally found in proteins are referred to as esential amino acids
amino acids
segment of DNA w/c determines the base sequence of nucleotide in the messenger ribonucleic acid (m-RNA) that makes up the code for a certain biological function
gene
the mechanism of cell division by w/c the genetic and chromosome composition of a cell is faithfully reproduced in each of the daughter cells;
means of growth and replacement in multicellular organisms
mitosis
special kind of cell division in sexually reproducing organisms whereby the chromosomes number of the cells is reduced to half
meiosis
process by w/c the germinal cells divide to produce haploid cells each carrying only one-half of the genetic complement of the individual
meiosis
genetic materials is transmitted from parent to offspring is made possible through the reduction division of the germinal cells and subsequent union of the gametes
meiosis
cell, tissue, or organism that contains two genomes or chromosome set
diploid
cells that contain half as many chromosome as the somatic cells
haploid
mechanics by w/c the gene i avle to synthesize protein in the cell underlies the realationship among G, and E in the formation of phenotype (P) of the organism
the G x E interaction
refers to the specific combination of genes that are associated w/ particular chracteristic of indivudual;
genotype
totality of non-genetic factors affecting the indivudual
environment
the observable manifestation of a given character of an individual; this can be change but the genotype remains
phenotype
may be active only when they occur in pairs of alleles during the diploid phase
gene action
one of two or more alternative forms of a gene w/c are usually recognizable by the phenotype
allele
directly responsible for the synthesis of a certain biochemical products during cell metabolism
structural genes
control or regulate the function of other genes; may function in terms of quantity, quality or timing of the activity of certain structural genes
regulator genes
action of genes as they influence genotypic values (3)
- additive
- dominance
- epistasis
pair of allelic genes contribute independently to the genotypic value
- additive