Chapter 10

STUDY
PLAY

Terms in this set (...)

heredity
Passing of traits from parents to offspring
trait
A characteristic that an organism can pass on to its offspring through its genes.
genetics
Scientific study of heredity
gamete
A haploid cell such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote.
fertilization
Process in sexual reproduction in which male and female reproductive cells join to form a new cell
zygote
Fertilized egg
pollination
The transfer of pollen from male reproductive structures to female reproductive structures in plants
hybrid
An organism that is the offspring of genetically dissimilar parents or stock
allele
An alternative form of a gene.
dominant
Describes a trait that covers over, or dominates, another form of that trait.
recessive
Describes a trait that is covered over, or dominated, by another form of that trait and seems to disappear.
law of segregation
Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
phenotype
An organism's physical appearance, or visible traits.
genotype
An organism's genetic makeup
homozygous
An organism that has two identical alleles for a trait.
heterozygous
An organism that has two different alleles for a gene
law of independent assortment
Each pair of alleles segregates independently of each other pair of alleles during gamete formation
diploid
(genetics) an organism or cell having two sets of chromosomes or twice the haploid number
-1 form mom and 1 from dad
-most cells have these
haploid
(genetics) an organism or cell having only one complete set of chromosomes
-half the number of chromosomes
-one of each kind of chromosome
-when 2 haploid cells come together it makes a full set again
homologous chromosome
Chromosomes that have the same sequence of genes and the same structure
-paired one from mom and one from dad
-only diploid cells have these
-one allele is on each paired chromosome
meiosis
(genetics) cell division that produces reproductive cells in sexually reproducing organisms
-cell division that ends in 4 haploid cells
-produces gametes
sperm
Male sex cell
egg
Female sex cell
sexual reproduction
A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents
-resultes in zygote with a full# of chromosomes
crossing over
Process in which homologous chromosomes exchange portions of their chromatids during meiosis.
-only occurs during prophase 1 of meiosis
-chromosomes swap genetic info
-provides a major source of genetic variation among organisms
genetic recombination
A new mixture of genetic material is created.
-when crossing over and independent assortment occurs
-important variation for revolution
nodisjunction
failure of homologous chromosomes to separate properly during meiosis; results in gametes with too many or too few chromosomes
-when homologous chromosomes don't separate properly during meiosis
-can result in polyploidy