Genetics Flashcards
What is a ploidy number?
Number of copies of each chromosome
Ex: humans= two copies of each chromosome from mom/dad
2n=46
What is a haploid number?
One copy of each chromosome (distinct)
Ex: gamete n=23
What is a chromosome?
Thread-like structure of nucleotides
What is a chromatid?
Each of the two thread like strands in which a cell divides into
What is a sister chromatid?
Two identical copies of a single chromosome
What is a nonsister chromatid?
Two chromatids of a homologous pair
What is a homologous pair?
Same chromosome from mom/dad
What is a tetrad?
Homologous pairs when lined up at the metaphase plate
What is an allele?
Different forms of a gene
What is a locus?
Where a gene is located on a chromosome
What is a centrosome?
Pair of centrioles
What is a centriole?
Triplet micro tubule structure from which the mitotic spindle is formed
What is independent assortment?
“Law of segregation”
Allele pairs seperate independently during the formation of gametes (meiosis 1/ metaphase 1)
What is Mendel’s Model?
- Multiple alleles for one phenotype
- For each character, an individual inherit two alleles; one from each parent
- If two alleles at the same locus differ, the dominant allele will determine appearance
- The law of segregation; the two alleles for a character segregate during gamete production and hence end up in different gametes
What did Mendel discover?
Some traits are dominant, some are recessive
What is genetics?
Scientific study of heredity
What is heredity?
Transmission of traits from one generation to another
What is a character?
Heritable features that vary among individuals
What is a trait?
(Phenotype) variant for the character
What is a model organism?
An organism that is widely used because it is easy to maintain in a lab setting