Biology A Ch. 11
Form of a gene
Both alleles are completely expressed.
Homologous chromosomes exchange portions of the chromatids during meiosis
Cell with two sets of homologous chromosomes
Egg or sperm cell
Genetic makeup of a an organism
Cell with one set of homologous chromosomes
Having two different alleles for a particular gene
Chromosomes where one set comes from the male parent and one set comes from the female parent.
Having two identical alleles for a particular gene.
Offspring of crosses between parents with different traits
Situation in which one allele is not completely dominant over another.
The number of chromosomes per cell is cut in half.
Gene that has more than two alleles
Physical characteristics of an organism
Trait controlled by two or more genes
principle of dominance
Some alleles are dominant and some are recessive
principle of independent assortment
Genes ofr different traits can segregate independently during the formation of gametes.
Specific characteristic of an individual that varies.
chromosomes replicate and chromatin condenses
-pairing of homologous chromosomes occurs, each chromosome consists of two chromatids and crossing over occurs
chromosome centromeres attach to spindle fibers and HC line up at the equator
HC separate and move to opposite poles of the cell
the spindle fibers break down, chromosomes uncoil and form two nuclei, the cell divides
chromosomes condense, spindles form in the new cells and attach to chromosomes.
centromeres of chromosomes line up randomly at the equator of each cell.
centromeres split, sr. chromatids separate and move to opposite poles
four nuclei form around chromosomes, spindles break down, cells divide.
four new cells have formed, each nuleus contains a haploid number of chromosomes.