Unit 2 Flashcards
Gregor Mendel
Australian monk who worked with pea plants and was the founder of mendelian genetics
Heredity
Passing off of traits from parents to offspring
Genes
Factors that control traits, they are on chromosomes and contain DNA
Alleles
Alternate forms of genes
Principle of dominance
If the dominant and recessive gene are there, the dominant gene will always be shown
Law of segregation
Offspring inherit traits from both parents
Genotype
Combination of alleles, represented by letters (homozygous, heterozygous dominant or heterozygous recessive)
Phenotype
What a trait looks like when expressed
Test cross
Used to see if an organism is homozygous dominant or heterozygous. Involves crossing an unknown genotype with homozygous recessive, will determine unknown allele.
Incomplete dominance
A blending of traits, represented with R and R’
Co dominance
Both traits are expressed, with have one letter with two superscripts
Multiple alleles
When a gene has more then one possible alleles for a given trait
Sex linked inheritance
T.H. Morgan used fruit flies
Pedigrees
Charts that track inheritance of a certain trait alone members of a family, birth order goes from left to right
Affected male
Filled in rectangle
Not affected male
Not filled in rectangle
Affected female
Filled in circle
Not affected female
Not filled in circle
Mitosis
The process by which nuclear material is asexually divided in somatic cells (body cells). Parent cells and daughter cells all have 46 chromosomes which is the diploid number (full number)
Interphase
Cell grows and prepares for cell division by duplication DNA
Prophase
Doubles chromatin strands shorter and thicken to form chromosomes, nuclear membrane and nuclei disappear, centrioles split, one travels to each pole of the cell. Spindle fibres attach to centromere of each chromosome
Metaphase
Spindle fibers pull chromosomes into a line across the middle of the cell
Anaphase
Spindle fibers contract and shorten, pulling centromere apart. Each single stranded chromosome moves to an opposite pole of the cell
Telophase
Spindle fibers disappear, nucleolus appears in each new nucleus. Single stranded chromosomes start to uncoil to form chromatic. Cytokinesis occurs