Chapter 10 Vocabulary Flashcards
heredity
transmission of traits from one generation to another
variation
demonstrated by difference in appearance that offspring show from parents and siblings
genetics
scientific study of heredity and variation
genes
units of heredity made up of DNA
gametes
sex cells (sperm, egg, pollen)
locus
gene location on a certain chromosome
asexual reproduction
single individual passes genes to offspring without fusion of gametes (produces clones)
sexual reproduction
two parents make offspring with unique combinations of genes (requires fusion of gametes)
somatic cells
non-sex cells
karyotyoe
ordered display of chromosomes from a cell
homolog
homologous chromosomes with same length shape, and carrying genes controlling the same characteristics
sex chromosomes
determine sex of individual (XX = female, XY = male)
autosomes
non-sex chromosomes (22 pairs)
diploid cell
cell with two sets of chromosomes (2n, in humans = 46)
haploid cell
cell with one set of chromosomes (gametes) (n, 23 in humans)
ovum
unfertilized egg
fertilization
union of gametes
zygote
fertilized egg
meiosis
cell division producing four HAPLOID daughter cells, in animals: producing sperm and eggs, in plants: producing pollen and spores
sporophyte
diploid organism that makes haploid spores by meiosis
gametophyte
an organism that uses spores to grow through mitosis into a haploid organism, example of alternation of generations
sister chromatid cohesion
sister chromatids closely associated along all lengths
crossing over
non-sister chromatids exchange DNA segments
chiasmata
X-shaped regions of homlogs
kinetochore
protein complex associated with centromere of chromosomes where microtubules attach
cytokinesis
active cell splitting
recombination
a process by which pieces of DNA are broken and recombined to produce new combinations of alleles
synapsis
two members of homologous pair of chromosomes associate along their length, allele by allele (happens during Prophase I)
synaptonemal complex
zipper-like structure formed during synapsis of Prophase I
mutation
changes in DNA
independent assortment
each pair of chromosomes sorts maternal and paternal homologs into daughter cells, separate from other pairs
