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8Sci CH13
8th Science CH13 Reproduction
Term | Definition |
---|---|
body cell | most numerous type of cell in your body-produces two identical copies of itself by mitosis and contain twice the number of chromosomes as sex cells |
eggs | female sex cells; contains a food supply, has 23 chromosomes and develops in the ovaries in relatively small numbers |
meiosis | process of cell division of all reproductive cells; involves two divisions of the chromosomes in the original cell, producing four new cells, each with half the number of chromosomes found in the body cell of that organism |
menstrual cycle | in human females, the monthly cycle that prepares the reproductive system for fertilization during which the uterine lining thickens, an egg is release, and if unfertilized is discarded in a process called menstruation |
menstruation | in human females, the monthly discharge of the disintegrated, unfertilized egg along with the uterine lining and blood through the vagina; usually lasts four to six days |
ovary | in human females, ovaries are the two sex organs in which eggs are produced by meiosis, which in females begins before birth and continues at sexual maturity, when an egg is released from the ovary every 28 days until the individual is 45 to 55 years old |
pistil | female reproductive organ of flowering plants composed of a sticky stigma, a stalk-like style, and a rounded base, which is its ovary |
sex cell | reproductive cells formed through meiosis, a process that begins in an organism’s reproductive organs and results in the formation of eggs or sperm, each of which contain half the number of chromosomes as the body cell of the parent organism |
sperm | male sex cells; human sperm are microscopic, have tails, can swim, contain 23 chromosomes, and are produced in large numbers by the testes |
stamen | in flowering plants, the male reproductive organ whose saclike anther is held up by a long filament; anthers produce sperm-containing pollen grains, which are transferred to the female’s sticky stigma by wind, birds and insects |
testis | in human males, teste are the two sex organs that produce sperm by meiosis when the body reaches sexual maturity, usually ages 10 to 14, with the amount of sperm gradually decreasing with age |