Ch. 13 Vocab Flashcards
the X-shaped microscopically visible region where homologous nonsister chromatids have exchanged genetic material through crossing over during meiosis, the two homologs remaining associated due to sister chromatid cohesion
chiasma
the reciprocal exchange of genetic material between nonsister chromatids during prophase 1 of meiosis
crossing over
the junction where one neuron communicates with another cell across a narrow gap by releasing neurotransmitters
synapse
in organisms that have alteration of generations, the multicellular haploid form that produces haploid gametes by mitosis
gametophyte
in the life cycle of a plant or alga undergoing alteration of generations, a haploid cell produced in the sporophyte by meiosis; in fungi, a haploid cell, produced either sexually or asexually, that produces a mycelium after germination; can divide by mitosis to develop into a multicellular haploid individual without fusing with another cell
spores
the multicellular diploid form that results from the union of gametes; produces haploid spores by meiosis that develop into gametophytes
sporophyte
a life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae
alteration of generations
a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication; results in cells with half the number of chromosome sets as the original cell
meiosis
the diploid product of the union of haploid gametes during fertilization; a fertilized egg
zygote
the union of haploid gametes to produce a diploid zygote; the addition of mineral nutrients to the soil
fertilization
a cell containing only one set of chromosomes
haploid cells
a cell containing two sets of chromosomes
diploid cells
a chromosome that is not directly involved in determining sex; not a sex chromosome
autosomes
a chromosome responsible for determining the sex of an individual
sex chromosomes
a pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci; aka homologs
homologous chromosomes
a display of the chromosome pairs of a cell arranged by size and shape
karyotype
any cell in a multicellular organism except a sperm or egg
somatic cell
the generation-to-generation sequence of stages in the reproductive history of an organism
life cycle
a lineage of genetically identical individuals or cells
clone
a type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the parents
sexual reproduction
the generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts)
asexual reproduction
a haploid reproductive cell, such as an egg or sperm
gametes
a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA or RNA
genes
the scientific study of heredity and hereditary variation
genetics
the transmission of traits from one generation to the next
heredity
a chromosome created when crossing over combines the DNA from two parents into a single chromosome
recombinant chromosomes
