Cell Division and Mendelian Genetics Flashcards
what is mitosis?
somatic, or body cell division
what type of division is mitosis?
multiplication division, diploid to diploid
what is mitosis necessary for?
differentiation and growth
after mitotic division, how many chromosomes do the daughter cells have?
the same number as the parent cells
what happens to the chromosomes prior to cell division?
they are replicated
what are identical copies of the same chromosome called?
chromatids
what happens to DNA when chromosomes replicate?
DNA also replicates
how many phases are in mitosis?
4
list and describe each of the 4 phases of mitosis
prophase: chromosomes condense, nuclear envelope disappears
metaphase: chromosomes align at equatorial plate
anaphase: sister chromatids separate, centromeres divide
telophase: chromatin expands, cytoplasm divides into 2 daughter cells (cytokinesis)
what is meiosis?
gamete cell division
what kind of division is meiosis?
reduction division, diploid to haploid
what is the key difference between mitosis and meiosis?
in meiosis, daughter cells end up with half the chromosomes as the parent cells, haploid
what big thing happens in meiosis I
crossing over
how does crossing over occur in meiosis I?
chromosomes come together in pairs during prophase I
what is meiosis II?
a mitotic division occurring in haploid cells, with 4 daughter cells resulting from the division
how many functional sperm cells come from one round of meiosis?
4
how many functional ovum come from one round of meiosis?
1, and 3 polar bodies
what is the law of segregation?
each individual has 2 factors for a trait which separate during gamete formation, and each gamete has only one factors from each pair of factors, so fertilization gives each new individual 2 factors for each trait
what determines the characteristics of an organism and where are they found?
genes, on the chromosome
what are homologous chromosomes?
members of a pair that carry genes for the same traits in the same order
what are alleles?
alternate forms of a gene for the same trait that are always at the same locus on each chromosome of a homologous pair
what are the genotypic and phenotypic ratios of a monohybrid/one-trait cross?
g- 1:2:2
p- 3:1
what is the probability rule for genetic crosses?
the chance or 2 or more independent events occurring together is the product of their chance of occurring separately
what is a one trait test cross?
used to determine the likely genotype of an individual with the dominant phenotype
what do the results of a one trait test cross tell you if there are any offspring produced with the recessive phenotype?
the dominant parent must be heterozygous
what is the law of independent assortment?
each pair of factors assorts independently, so all possible combinations of factors can occur in the gametes
