Chapter 12 Flashcards
Cell Division
The ability of organisms to produce more of their own kind best distinguishes living things from nonliving matter (growth and repair)
Asexual Reproduction
A type of reproduction that creates offspring that is genetically identical to the parent; only one parent
Chromatin
A complex of DNA and protein that condenses during cell division
Stomatic cells
non-reproductive cells; have two sets of chromosomes
Gametes
reproductive cells - sperm and egg; have half as many chromosomes as somatic cells
Sister chromatids
joined copies of an original chromosome; attached along their lengths by cohesins
Centromere
the narrow “wait” of the sister chromatids where the two are most closely attached
Mitosis
the division of genetic material in the nucleus
Cytokinesis
the division of the cytoplasm
Phases of the cell cycle
1) mitotic (M) phase (mitosis and cytokinesis)
2) interphase
Parts of Interphase
1)First Gap (G1)
2) Synthesis phase (S)
3)Second Gap (G2)
First Gap
G1; cell growth, protein/enzyme/nutrient synthesis
synthesis phase
DNA replication
Second Gap
G2; organelle synthesis; edit new DNA
Phases of Mitosis
1) Prophase
1.5) Prometaphase
2) Metaphase
3) Anaphase
4) Telophase
Prophase
Chromatin condenses; sister chromatids are formed; Mitotic spindles are formed
Prometaphase
Nuclear envelope breaks down; microtubules connect to sister chromatid’s kinetochore
Metaphase
Sister Chromatids line up along the middle of the cell
Anaphase
Chromosomes are pulled apart and brought to opposite sides of the cell
Telophase and Cytokinesis
The cell breaks apart into two cells (original and the daughter cell)
Centrosome
a cellular organelle that helps organize microtubules
Kinetochore
the place on the chromosome where the microtubules connect
Metaphase plate
an imaginary line that runs across the cell, dividing the cell into hemispheres at which the chromosomes line up on during metaphase
Binary fission
“division in half”; refers to the process of Prokaryotes that double in side and then divides to form two cells
Cell cycle control system
Similar to a clock and has checkpoints along it (G1, M, and G2)
Cyclins and cyclin-dependent kinases (Cdks)
Two types of regulatory proteins involved in cell cycle control; the activity of a Cdk rises and falls with changes in concentration of its cyclin partner
MPF
maturation-promoting factor; a cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into the M phase
G0 phase
A phase of a cell that is a non-dividing state; occurs when the cell does not receive a green-light from the G1 checkpoint
Enzyme seprase
a protease enzyme that plays a critical role in cell division by separating sister chromatids during mitosis
growth factor
A protein released by certain cells that stimulates other cells to divide
density-dependent inhibition
A phenomenon in which crowded cells stop dividing; an example of an external physical factor
anchorage dependence
The property of most animal cells that it must be attached to something to be able to divide
Transformation
the process in which cells in culture acquire the ability to divide indefinitely, causing them to behave like cancer cells
Benign tumors
A tumor that remain at the original site if their genetic and cellular changes do not allow them to move to or survive at another site
Metastasis
The spread of cancer cells to locations distant from their original site
Malignant tumor
includes cells whose genetic and cellular changes enable them to spread to new tissues and impair the functions of one or more organs
