Chromosomes
rod-shaped structures made of DNA and proteins are
Histones
the DNA in eukaryotic cells wraps tightly around proteins called
Chromatid
one of the two halves of a chromosome; that becomes visible during meiosis or mitosis
Centromere
the region of the chromosome that holds the two sister chromatids together during mitosis
Chromatin
a complex of proteins and DNA strands that is unwound for use during interphase
Sex Chromosomes
chrosomes that determine the sex of an organism, and they may also carry genes for other characteristics (1 pr)
Autosomes
all of the other chromosomes in an organism that are not sex chromosomes (22pr)
Homologous Chromosomes
two copies of each autosome that carry genes for the same traits and look the same
Karyotype
a picture of chromosomes from a cell, may determine gender or chromosomal disease
Diploid
body or somatic cells having two sets of chromosomes
Haploid
sperm cells and egg cells that contains only one set of chromosomes
Binary Fission
the division of a prokaryotic cell into two offspring cell
Mitosis
new body cells with genetic material that is identical to the genetic material, of the original cell; used to repair and replace body cells and during growth
Asexual Reproduction
the production of the offspring from the one parent
Meiosis
occurs during the formation of gametes (sperm and egg cells)
Gametes
haploid reproductive cells (sperm and egg cells)
Interphase
the time between cell division
Cytokenisis
the division of the cells cytoplasm
Prophase
the first phase of mitosis when chromosomes are formed and the nuclear membrane starts to dissolve
Spindle Fibers
the microtubules made by centrioles that extend to attach to chromosomes to move them during cell division.
Metaphase
the second phase of mitosiswhere the chromosomes line up in the middle of the cell
Anaphase
the chromatids of each chromosome separate at the centromere and slowly move toward the poles of the cell (pulled by spindle fibers)
Telophase
last phase of mitosis where the cell is divided into two parts; spindle fibers disassemble, chromosomes unravel into chromatin
Cell Plate
during telophase in plant cells this is the beginning of a new cell wall that starts to grow between the newly formed cells
Synapis
the pairing of homologous chromosomes, which does not occur in mitosis only in meiosis
Tetrad
each pair of homologous chromosomes
Crossing-Over
portions of chromatids may break off and attach to adjacent chromatids on a homologous chromosome
Genetic Recombination
material between maternal and paternal chromosomes sometimes end up on the same chromosome due to crossing over
Independent Assortment
random separation of the homologous chromosomes mean that we can't predict if a baby will get the chromosomes that came from mom or the one from dad
Spermatogenesis
the production of sperm cells; makes 4 sperm
Oogenesis
the production of mature eggs or ova; makes 1 egg and 3 polar bodies
Polar Bodies
the other three products of meiosis; recycled by the body
Sexual Reproduction
production of offspring through meiosis and the union of a sperm and an egg; 2 parents contribute DNA