Biology
Terms
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copy deck
- sex chromosomes
- the chromosomes that determine a person's sex (X and Y chromosomes); also perform other functions
- deletion
- when a fragment of a chromosome is lost
- benign tumor
- when the abnormal cells remain at the original site
- metastasis
- the spread of cancer cells via the circulatory system beyond their original site
- cell plate
- when the vesicles fuse
- sister chromatids
- contain identical copies of the DNA molecule
- sexual reproduction
- the reproduction process that involves fertilization
- mitotic spindle
- a football shaped structure of microtubules that guides the separation of the two sets of daughter chromosomes
- asexual reproduction
- the production of offspring by a single parent without participation of sperm or egg
- genetic recombination
- the production of gene combinations different from those carried by the original chromosomes
- karyotype
- an ordered display of magnified images of an individual's chromosomes arranged in pairs, starting with the longest; shows the chromosomes condensed and doubled, as they appear in metaphase of mitosis
- prometaphase
- nuclear envelope breaks into fragments and disappears (see pg. 130)
- growth factor
- a protein secreted by certain body cells that stimulates other cells to divide
- crossing over
- an exchange of corresponding segments between two homologous chromosomes
- translocation
- the attachment of a chromosomal fragment to a nonhomologous chromosome
- anchorage dependence
- when animal cells must be in contact with a solid surface to divide
- carcinomas
- cancers that originate in the external or internal coverings of hte body, such as the skin or lining of the intestine
- chiasma
- the sites of crossing over that appear as X-shaped regions
- prophase
- when changes occur in both the nucleus and the cytoplasm (see pg.130 for more details)
- centrosomes
- clouds of cytoplasmic material that in animal cells contain centrioles
- metaphase
- mitotic spindle is fully formed, with its poles at opposite ends of the cell (see pg. 131)
- density-dependent inhibition
- animal cells growing on the surface of a dish multiplying to form a single layer that usually stop dividing when they touch one another
- duplication
- when a fragment from one chromosome joins a to sister chromatid or homologous chromosome
- autosomes
- the other 22 pairs of chromosomes besides the sex chromosomes
- diploid cell
- any cell with two homologous sets of chromosomes
- mitotic phase (M phase)
- the part of the cell cycle when the cell actually divides; this accounts for about 10% of the total time required for the cell cycle
- locus
- the particular place where a gene is located
- telophase
- roughly the reverse of prophase (see pg. 131)
- nondisjunction
- the occasional mishap when the meiotic spindle distributes chromosomes to daughter cells unsuccessfully and the members of a chromosome pair fail to separate
- cell division
- the reproduction of cells
- chromosomes
- the structures that contain most of an organisms DNA
- mitosis
- when the nucleus and its contents including the duplicated chromosomes, divide and are evenly distributed to form two daughter nuclei
- interphase
- a time when a cell's metabolic activity is very high and the cell performs its various functions within the organism; most of cell cycle is spent here
- cancer cells
- cells that divide excessively and can invade other tissues of the body
- cell cycle control system
- a cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle
- cleavage furrow
- a shallow groove in the cell surface
- chromatin
- a combination of DNA and protein molecules
- zygote
- the resulting fertilized egg from sexual intercourse
- trisomy 21
- a karyotype where there are three number 21 chromosomes, making 47 chromosomes in all
- centromere
- where the two chromatids are joined together tightly
- homologous chromosomes
- the two chromosomes composing a pair
- gametes
- the egg and sperm exceptions; each has a single set of chromosomes: 22 autosomes plus a single sex chromosome
- life cycle
- the sequence of stages leading from the adults of one generation to the adults of the next
- anaphase
- begins when the two centromeres of each chromosome come apart, separating the sister chromatids (see pg. 131)
- leukemias and lymphomas
- cancers of blood-forming tissues such as bone marrow, spleen, and lymph nodes
- fertilization
- the union of a sperm and an egg
- cell cycle
- an ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division into two cells
- tumor
- an abnormally growing mass of body cells
- haploid cell
- a cell with a single chromosome set
- genome
- one set of genetic information
- Down syndrome
- a syndrome where a person has an extra copy of chromosome 21
- malignant tumor
- spreads to neighboring tissues and other parts of the body, displacing normal tissue and interrupting organ function as it goes
- inversion
- when a fragment reattaches to the original chromosome but in the reverse direction
- binary fission
- a type of cell division ("dividing in half")
- cytokinesis
- when the cytoplasm is divided in two
- sarcomas
- arise in tissues that support the body such as bone and muscle