click below
click below
Normal Size Small Size show me how
Cell Division
cell division/reproduction
Term | Definition |
---|---|
Species | group of organisms that share certain characteristics and can reproduce with one another |
development | period of time in which and individual organism grows and becomes more complex; development ends with the ability to reproduce in adulthood |
asexual reproduction | only one parent involved; results in offspring that are genetically identical, or exact copy, of the parent |
sexual reproduction | involves two parents and creates offspring with some genetic material (DNA) from each parent; offspring can look like either parent, but they are NEVER the same; genetically unique offspring |
types of cell division | Mitosis and meiosis |
Mitosis | cell division where the cell's genetic material divides creating two sets of genetic material; the new daughter cell is an exact copy of the parent cell and only one new cell is made |
Meiosis | cell division where the cell's genetic material divides twice and creates sex cells with HALF the number of chromosomes as body cells; they are gametes. |
male sex cells (gametes) | sperm |
female sex cells (gametes) | eggs |
result of meiosis in males | one diploid cell (cell with full chromosome number) results in 4 sperm cells |
result of meiosis in females | one diploid cell (cell with full chromosome #) results in one egg and 3 polar bodies |
haploid | represented as (n); contains half the number of chromosomes of the species |
diploid | represented as (2n); contains a full set of chromosomes |
recombination | occurs during fertilization, process where the genetic material from one haploid cell combines with the genetic material from another haploid cell to create a fully functional diploid cell |
zygote | cell that contains all of the genetic info required for an organism to perform all life functions; the zygote divides by mitosis to form a multi-cellular organism in multi-cellular organisms |
Differentiation | Cells become different from one another; in the embryo "all the DNA is exactly the same" * certain genes are activated or deactivated in certain cells. As a result, cells become different from one another * every single cell in body has same DNA |
Mutations | change in the normal sequence of DNA, possibly resulting in a change in the message carried by RNA; may result in a defective or changed protein |
Selective breeding | process of breeding plants or animals to produce new varieties with desirable traits |
reproduction | For any species to survive past a single generation, reproduction must occur; two main types Asexual and Sexual |
genetic engineering | humans use technology to alter the genetic information of an organism |
Biotechnology | application of technology on biological sciences (ie. cheese, yogurt & bread) |
gene expression | gene that "show's up" in an organism. an expressed gene is functional; the environment can influence cells to activate or inactivate certain genes |
gene | a segment of DNA (on a chromosome) that contains code for a specific trait |
trait | a characteristic that is passed from parent to offspring through the genes |
heredity | the passing of traits from parent to offspring |
DNA | (deoxyribonucleic acid) the material found in all cells that contains genetic information about that organism |
chromosome | a thick threadlike structure that contains genetic information in the form of DNA |
clone | an organism that is genetically identical to the organism from which it was produced |
subunit | the section of a DNA molecule that contains a sugar, a phosphate, and a base |
bond | a chemical link between atoms that hold molecules together |
template | the pattern for a new molecule |
expressed | the way that an unseen gene is seen in an organism as an actual physical trait |
Body cells | all cells except sex cells (ex: skin cells, liver cells, heart cells...) |
Gametes | sex cells aka reproductive cells (egg and sperm). also called haploids because they have half the number of chromosomes |
Fertilization | when egg and sperm meet, happens in the fallopian tubes in a woman |
Hormones | proteins used in the body to regulate and control feedback mechanisms, travel in the blood |
Testosterone | male sex hormone that stimulates production of sperm made by the testes (organ) |
Estrogen/progesterone | female sex hormones that regulate female reproductive cycle and influences the uterus (an organ) |
Uterus | organ in the female reproductive system; where fetal development happens, the hormone estrogen influences this organ |
Fallopian tubes | in the female reproductive system; where fertilization happens |
Ovaries | in the female reproductive system; where eggs are made through meiosis |
Placenta | STRUCTURE in the uterus with developing fetus, only some things can go from mom to baby but no direct blood contact |
Testes | in the male reproductive system; makes sperm through meiosis |
Ovulation | release of the egg from the ovary |
Menstruation | shedding of the uterus lining, also known as a woman's period |