Studied by 9 people
the storage and transmission of genetic information from one generation to the next occurs through meosis
genetics
study of hereditary variation
heredity
transmission of traits from one gen to the next
asexual
single individual, no fusion of gametes, clones, mutations are the only source of variation, mitosis
sexual
two parents, offspring are unique combinations of genes from parents, genetically varied from parents and siblings, meosis
homologous chromosome
a pair of chromosomes that carry the same genetic information and are identical
karyotypes
display of chromosome pairs ordered by size and length
somatic cells
diploid (2n)
two completed sets of each chromosome
gametic cells
haploid (n)
one set of each chromosome
autosomes
chromosomes that do not determine sex
sex chromosomes
X and Y; determine sex
life cycle
the sequence of stages in the reproductive history of an organism from conception to its own reproduction; fertilization and meiosis alternate
meiosis
process that creates haploid gametes cells in sexually reproducing diploid organisms
2 divisions, 4 haploid daughter cells, genetically unique
Interphase
G1, S, and G2
Prophase I
homologous chromosomes pair up to form tetrads with unique combinations of DNA
Metaphase I
independent orientation tetrads line up at the middle
Anaphase I
pairs of homologous chromosomes seperate while sister chromatids still attached
Telophase I and Cytokinesis
nuclei and cytoplasm divide to make two daughter cells with haploid set’s in each
Prophase II
no chromosomes cross over but spindle fibers form
Metaphase II
chromosomes line up at the metaphase plate and are still unique
Anaphase II
sister chromatids separate and move towards opposite poles
Telophase II and Cythokinesis
4 haploid cells are created, nuclei reappears, and each daughter cell is genetically unique
Gregor Mendel
Austrian monk who experimented on pea plants and discovered the basic principles of heredity
true-breeding
organisms that produce offspring of the same variety over many generations of self pollination
P generation
true-breeding parental generation
F1 generation
first filial hybrid offspring of P generation
all hybrids
F2 generation
second filial offspring of the G1 generation
always results in a 3:1 ratio
punnett squares
disgrams used to predict the allel combinations of offspring form a cross with known genetic compositions
homozygous
organism that has a pair of identical alleles for a character
AA
heterozygous
organism has two different alleles for gene
genotype
genetic makeup (alleles) of an organism
phenotype
organism’s appearance, which is determined by the genotype
testcross
help determine if dominant trait is homozygous or heterozygous
law of segregation
each gene separates from its corresponding allele so that each reproductive cell only contains one allele
law of independent assortment
genes for one trait are not inherited with genes for another trait; only applies to those located on different chromosomes
alleles
alternate versions of gene
monohybrid crosses
cross between true-breeding plants that produce F1 hybrids
dihybrid crosses
cross between true-breeding for two traits that produce F1 dihybrids
9:3:3:1
genotype
the genetic makeup and alleles
phenotype
appearance determined by the genotype
multiplication rule
the probability that two or more independent events will occur together in some specific combination
addition rule
the probability that two or more mutually exclusive events will occur
pedigree
family trees that give a visual of inheritance patterns of particular traits
non-Mendelian Genetics
varying degrees of dominance; many traits produced through many genes; some are on sex chromosomes
incomplete dominance
neither allele is fully dominant and creates a mix
red and white —> pink
codominance
two allele that affect phenotype are post expressed
AB blood type
multiple alleles
genes that exist in forms with more than two alleles
epistasis
a phenotype expression of a gene at one locus affects a gene at another locus
polygenic inheritance
effect of two or more genes acting on a single phenotype
sex-linked genes
genes located on either to X or Y chromosomes
genetic recombination
production of offspring with a new combination of genes from parents
parental types
offspring with the parental phenotype
recombinants
offspring with phenotypes that are different from the parents
linked genes
genes located near each other on the same chromosome that tend to be inherited together
linkage map
genetic map based on recombination frequencies and distance is expressed by map units
chi-square test
form of statistical analysis to compare actual data to expected results
nondisjunction
chromosomes fail to seperate properly in meiosis I or II
down syndrome
extra 21 chromosome
turner syndrome
one X chromosome is missing or partially missing in females
cri du chat
piece of chromosomes 5 is missing
klinefelter syndrome
two X and one Y chromosomes
digeorge syndrome
deletion of section on chromosome 22
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Flashcard (22)