Biology: Meiosis and Genetics Flashcards
Meiosis
type of cell division that produces four cells, each with half as many chromosomes as the parent cell
Karyotype
display of a person 46 chromosomes
Homologous Chromosomes
each of the matching pair of chromosomes, one inherited from each parent
Sex Chromosome
one of two chromosome sod the 23rd pair of human chromosomes, which determine an individuals gender
Diploid
(2n) having two homologous sets of chromosomes
Gametes
egg or sperm cell that contains single set of chromosomes, one from each homologous pair
Haploid
(n) having a single set of chromosomes
Fertilization
the fusion of the nuclei and cytoplasm of a haploid sperm cell and a haploid egg cell, forming a diploid zygote
Zygote
diploid cell formed when nucleus of a haploid sperm cell fuses with the nucleus of a haploid egg cell
Tetrad
group of four chromatids formed during prophase I of meiosis by the two sister chromatids in each of the two homologous chromosomes
Crossing Over
exchange of genetic material between homologous chromosomes during prophase I of meiosis
Genetic Recombination
new combination of genetic information in a gamete as a result of crossing over during prophase I of meiosis
Meiosis I
splitting the homologous chromosomes
Prophase I
same as mitosis, homologous chromosomes are going ton pair up and connect making tetrads, crossing over
Metaphase I
Tetrads are going to line up in the middle
Anaphase I
Homologous chromosomes are separated and pulled to opposite ends of the cell by the spindle
Telophase I and Cytokinesis
same as mitosis, two haploid cells are formed, chromosomes are still duplicated
Meiosis II
splitting sister chromatids
Prophase II
same as mitosis
Metaphase II
chromosomes line up in the center of the cell
Anaphase II
sister chromatids separate
Genetics
study of heredity
Cross Fertilization
process by which sperm from one flowers pollen fertilizes the eggs in a flower of a different plant
Hybrid
offspring of two different true breeding varieties
Monohybrid Cross
mating two organisms that differ in only one character
Allele
alternate form of a gene
Homozygous
having identical alleles for a gene
Heterozygous
having different alleles for a gene
Dominant
descriptive of an allele in a heterozygous individual that appears to be the only one affecting a trait
Recessive
descriptive of an allele in a heterozygous individual that does not appear to affect the trait
Punnett Square
diagram showing the probability of the possible outcomes of a genetic cross
Phenotype
observable traits of an organism
Genotypes
genetic makeup of an organism; an organisms combination of alleles
Testcross
mating of an individual of unknown genotype but dominant phenotype with a homozygous recessive individual
Dihybrid Cross
mating of two organisms that differ in two characters
Incomplete Dominance
when the heterozygous genotype has a phenotype is a mix of the two parents phenotypes
Codominance
inheritance pattern in which a heterozygote expresses the distinct traits of both alleles
Polygenic Inheritance
combined effect of two or more genes on a single character
Principle of Independent Assortment
alleles for different traits are passed on seperately
Genetic Linkage
tendency for alleles of genes on the same chromosome to be inherite together
Sex-Linked Gene
gene located on a sex chromosome
Principle of Segregation
During the production of gametes the two copies of each heredity factor segregate so that offspring acquire one factor from each parent.
Blending Hypothesis
An individuals phenotype is the result of the blending of the phenotypes of its parents.
Particulate inheritance
Characteristics can be passed from generation to generation through genes.
