cellular division vocab

centromere

centromere

a specialized region of the chromosome where the chromatids are joined. Each chromosome has one centromere

chromosomes

threadlike structures that are composed of DNA and protein

mitosis

the division of a cell to create two identical cells

cytokinesis

division of the cytoplasm

chromatin

a DNA and protein complex that is thin and fibrous; it will condense into distinct chromosomes during cell division

binary fission

it happens in bacteria cells when DNA duplicates and splits (asexual reproduction)

checkpoints

at certain times in the cell cycles the cell will check to see if everything is okay before moving on to the next step

cyclin

a protein involved in the regulation of the cell cycle, their concentration varies in cyclical fashion during the cell cycle

G₀ phase

a phase where the cell does normal metabolic “stuff”

G₁ phase

a checkpoint where if the cell passes, it will divide, but if the cell doesn’t pass, the cell will enter the G₀ phase and won’t divide

anaphase

a phase in mitosis when the chromatids get pulled apart and move to opposite sides of the cell

cell cycle

a sequence of events in the life of the cell that includes interphase (G₁, S, G₂) and the mitotic phase (P, M, A, T)

cell division

the reproduction of new cells, also used for replacing damaged cells and the growth of new cells

cell plate

a membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis

cell-cycle control system

a cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinated key events in the cell cycle

cleavage furrow

the first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate

cyclin-dependent kinase

a protein kinase (enzyme) that is active only when attached to a particular cyclin

density-dependent inhibition

a phenomenon in animal cells that causes them to stop dividing when when they come into contact with each other

G₂ phase

the second growth phase of the cell cycle that occurs after DNA synthesis

gametes

haploid reproductive cells that are produced by meiosis, human gametes have 23 chromosomes

genome

all the genes in an organism

interphase

a period in the cell cycle where the cell is not dividing, it is not a mitotic phase, the nucleus is present and chromosomes are not visible

kinetochore

proteins attached to the centromere that link each sister chromatid to the mitotic spindle

metaphase

a phase during mitosis where the chromosomes line up in the middle of the cells and kinetichore microtubles attach to the center or each chromosome

metaphase plate

an imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located

mitotic phase (M)

the phase of the cell cycle that includes mitosis (P, M, A, T) and cytokinesis

mitotic spindle

an assembledge of microtubles and associated proteins that is involved in the movement of chromosomes during mitosis (kinetichore microtubles)

mitosis promotion factor (MPF)

when Cdk actually joins with cyclin

prometaphase

the second stage of mitosis in which the nuclear envelope fragments and the spindle microtubles attach to the kinetochores of the chromosomes, it happens between prophase and metaphase

prophase

a phase during mitosis where the nucleus starts dissolving, spindle fibers form, and chomosomes become visible because the chromatin condenses, the cell is also diploid because it has maternal and paternal sets

s-phase

the synthesis phase of the cell cycle; the part of interphase during which DNA is replicated

sister chromatids

a set of duplicated chromosome attached to each other at the centromere, the two chromatids make up one chromosome

somatic cell

any cell other than a spem or egg

telophase

the last stage of mitosis, the nuclei reform and the chromosome content is the same in each nuclei, cytokinesis happens at the same time

asexual reproduction

a single individual is the parent which copies all of its genes into identically cloned offspring, but there is limited variation

autosome

the non-sex chromosome, for humans its pairs 1-22

diploid cell

a condition in which a cell contains 2 sets of chromosomes, 2n

fertilization

the union of two gametes

gamete

haploid reproductive cells, human ____ have 23 chromosomes

genes

units of heredity; it’s made of DNA found on the chromosomes

haploid cell

a condition in which cells contain 1 set (no homologous pair) of chromosomes, n

heredity

the passing of genes from parents to offspring

homologus chromosome

chromosomes that have the same centromere position, same genetic loci, and the same length, but have different alleles

karyotype

a display of individual somatic cell metaphase chromosomes

a display of a persons chromosomes

sex chromosomes

dissimilar chromosomes that determine an individuals sex, the 23rd pair

variation

inherited differences within a species

zygote

a diploid cell that results from the fusion of gametes

chiasmata

the point on a chromosome where it touches another chromosome during prophase I and metaphase I

crossing over

the homologus chromosomes swap information with each other

tetrad

the formation of homologus pairs meeting up in prophase I

genetics

the scientific study of heredity and heredity variation

synapsis

the pairing and physical connection of one duplicated chromosome to its homolog during prophase I

clone

an individual that is genetically identical to another individual

growth factor

a protein that must be present in the extracellular environment for the growth and normal development of certain types of cells

meiosis

a type of cell division in sexually reproducing organisms consisting of two rounds of cell division and it’s goal is to reduce the chromosome number in half

meiosis I

the first round of cell division in sexually reproducing organisms, it results in half the number of chromosome set as the original cell

meiosis II

the second round of cell division in sexually reproducing organisms, it results in half the number of chromosome set as the original cell