Cell Division Flashcards
Cell cycle
The series of events that occur in eukaryotic cells from cell formation through the end of cell division
Interphase
Longest phase of the cell cycle. A cell spends > 90% of its time in interphase
G1
(Growth 1) First stage of interphase. Cell doubles in size and produces all structures needed for cellular division
S
Second stage of interphase. Cell replicates its DNA such that it makes an exact copy of genetic material
G2
Third (final) stage of interphase. Cell prepares for cellular division by producing all the final necessary structures
Prophase
First stage of mitosis. Nucleolus of nuclear membrane dissapears. Centrioles form spindle fiber apparatus.
Metaphase
Second stage of mitosis. Homologous pairs line up at metaphase plate.
Anaphase
Third stage of mitosis. Spindle fibers attached at the Kinetochores and pull sister chromatids toward opposite poles
Telophase
Fourth (final) stage of mitosis. Chromosomes arrive at poles and begin to decondense. Nuclear membrane+nucleus return
Cytokinesis
Final stage of the cell cycle. Cytoplasm and organelles divide evenly. Animals form cleaveage furrow. Plants form cell plate
DNA
Deoxyribonucleic acid (genetic material in cells) can be in several forms, such as chromatin, chromosomes, chromatids, etc.
Chromatin
Thread-like form of DNA present from end of telophase until replication during synthesis of interphase
Chromatid
One half of a homologous pair of chromosomes
Sister chromatids
Each half is a sister chromatid to the other. They are genetically identical
Chromosome
Condensed form of chromatin. Exist as single chromatids before replication and homologous pairs afterwards.
Homologous pair of chromosomes
Identical sister chromatids joined at the centromere. Each chromatid is identical to the other
Centromeres
Structure that joins and holds together homologous pairs of chromosomes
Centrioles
Also called centrosomes, are organelles that assemble the spindle fibers during prophase.
Spindle fibers
Formed by centrioles/centrosomes. Attach to chromosomes at the kinetochore to move them around the cell
Cell plate
Formed in plant cells during cytokinesis to elongate the cell and allow a new cell to form
Cleavage furrow
Formed in animal cells during cytokinesis to “pinch apart” the cell membrane into two seperate cells
Haploid chromosome #
The chromosome number of the gametes of a given species (every breed of a species has the same) Half the species diploid number
Diploid chromosome #
The chromosome number of somatic cells of a given species (every breed of a species has the same) Twice the species haploid number.
Gametes
Egg cells in female animals, sperm cells in male animals. Ovule in female plants, pollen grain in male plants.
Somatic cells
General body cells (all but reproductive)
Sperm
Male gamete- always haploid # (animal cells)
Pollen Grain
Male gamete- always haploid # ( plant cell)
Egg
Female gamete- always haploid # (animal cells)
Ovule
Female gamete- always haploid (plant cells)
46 chromosomes
Diploid chromosome # for human somatic cells
23 chromosomes
Haploid chromosome # for human gametes
Nucleolus
Organelle inside the nucleus that produces ribosomes. DIsappears during mitosis
Nuclear membrane
Membrane that surrounds DNA, nucleolus and nucleoplasm. DIssolves during mitosis
Apoptosis
Normal, controlled death of cells
Parent cell
The original cell that begins the cell cycle right after cytokinesis, which eventually divides into 2 daughter cells
Daughter cell
2 cells formed during mitosis that is genetically identical to the parent cell
Equatorial/Metaphase plate
Imaginary line through the center of a cell where chromosomes line up during metaphase
Condensation of chromatin
Thread like chromatin condenses, shortens, and folds into itself to form thicker, more visible chromosomes.
Replication of chromosomes
The exact copying of a cells genetic material during S-phase of interphase
Micrograph
A photo taken through a microscope. often used to view cell cycle structures and phases
each chromosome contains ___ chromotids
2
each chromosome contains ___ chromatids
2
during which phase do chromosomes first become visible>
prophase
Tetrads
2 homologous pairs joined together (4 chromatids, 2 centromeres)
Does meiosis or mitosis occur in plants and animals?
Both
Does meiosis or mitosis include binary fission, budding, plantlets, tubers, and runners?
mitosis
Does meiosis or mitosis have 8 phases?
meiosis
Does meiosis or mitosis produce identical daughter cells?
mitosis
Does meiosis or mitosis result in haploid cells?
meiosis
Does meiosis or mitosis reproduce cells?
both
Does meiosis or mitosis have cellular division occur only once?
mitosis
Does meiosis or mitosis form tetrads?
meiosis
Does meiosis or mitosis result in 4 daughter cells?
meiosis
Does meiosis or mitosis involve crossing over?
meiosis
Does meiosis or mitosis start with one parent cell
mitosis
Does meiosis or mitosis involve sexual reproduction?
meiosis
Does meiosis or mitosis produce genetically different daughter cells from parent cells?
meiosis