ch 13 meiosis and sexual life cycles exam 3 Flashcards
genetics
scientific study of heredity and variation
heredity
the transmission of traits from one generation to the next
variation
differences in appearance that offspring show from parents and siblings (how similar and different we look)
genes
the units of heredity and are made up of segments of DNA (DNA is stretched and all our codes and traits are our genes)
gametes
sperm and eggs in which genes are passed to the next generation via reproductive cells
somatic cells
all cells in the body except gametes and their precursors
locus
a gene’s specific position along a chromosome
asexual reproduction
a single individual passes all genes to offspring without the fusion of gametes (sperm and egg)
sexual reproduction
two parents giving unique combinations of genes to offspring
life cycle
generation-to-generation sequence of stages in the reproductive history of an organism
how many pairs of chromosomes do human somatic cells have
23 pairs (one from mom and one from dad) but 46 total chromosomes
homologous chromosomes or homologs
two chromosomes in each pair are called homologous chromosomes or homologs and are the same length and shape and carry genes controlling the same inherited characters
diploid cell
has two sets of chromosomes (2n=46)
haploid cell
a gamete that contains a single set of chromosomes (n=23)
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