cell cycle and cell division Flashcards
how chromosome is formed?
in the nucleus of each cell the DNA molecule is packaged into thread like structure called chromosomes. each chromosome is made up of DNA tightly coiled many time around called histones that support its structure
internal sructure of histone
H2A, H2B, H3, H4
highly alkaline found in eukaryotic cell nuclei that package and order the DNA into structrtural units called_________?
nucleosome
parts of chromosome
telomere
shortarm
centromere
longer arm
sister chromatid
protective caps at the end of DNA molecules that make up our chromosomes
telomere
the region of a chromoses to whichh the microtubules of the spindle attach, via the kinetochore during cell division
centromere
different types of chromosome based on centromere position
metacentric- centromere in the middle of chromosome
submetacentric
acrocentric - chromomere near the end of the chromosomes
telocentric - chromomere at the end
what are the chromosal abnormalities
cru-du-chat syndrome
down syndrome
47, XXY (klinefelter syndrome)
turner syndrome
williams syndrome
is a group of symptoms that result from missing a piece of chromosome
cri-du-chat syndrome
autosomal deletion syndrome caused by a partial deletion of chromose 5 and is characteized by a distinctive, high pitched, catlike cry infancy with growth failure
cri-du-chat syndrome
chromosal condition that is asscociated with intellectual disability, facial appearance and weak muscle tone in infancy
down syndrome
genetic condition in which a huma male has an extra male (Y) chromosome
klinefelter syndrome
occurs when one of the two X chromosome s normally found in women is missing or incomplete
turner syndrome
caused by deletion of additional genetic material near the elastin gene on chromosome 7
william syndrome
what are the alterations of chromoses structures
deletion
duplication
inversion
translocation
occurs when a chromosome fragment lacking a centromere is lost during cell division
deletion
occurs when a fragment becomes attached as an exra segment to a sister chromatid
duplication
occurs when a chromosal fragment reattaches to the original chromosome but in the reverse orientation
inversion
a chromosal fragment joinsa nonhomologous chromosome
translocation
is an orderly set of stages that take place betweemn the time a cell divides and the time the resulting daughter cells also divide
cell cycle
give the cell cycle stages
interphase
-G1 phase
-S phase
-G2 phase
m-phase
- mitosis
-prophase
-metaphase
-anaphase
-telophase
-cytokinesis
is a process in which a cell may double its entire content in preparation for cell division
interphase
the cells contents are distributed into daughter cells
M-phase
a period when the cell increases in size in preparation for cell division
Gap 1 phase (G-phase) (growth)
period during which DNA is synthesized and chromosomess are replicated
synthesis phase
period when the cell continues to synthesize RNA and proteins and increase in size
G2 phase
the process of cell division which results in the production of two daughter cells from a single parent cell
mitosis
first phase of mitosis
prophase
the process that seperates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells
prophase
regions of DNA where the sister chromatids are most tightly connected
centromeres
a patch of protein found on the centromere of each sisters chromatid
kinetochore
chromosomes align along equator of the cell, with one kinetochore facing each pole
metaphase
sister chromatids seperate
anaphase
spindle fibers disintegrate
telophase
cytokinesis occurs, enclocing each daughter nucleus into a seperate cell
telophase
division of the cytoplasm to form two new cells, overlaps with the final stages of mitosis
cytokinesis
involves combining the genetic information of one parent with that of the other parent to produce a genetically distinct individual
meiosis
a division of the nucleus that reduces chromosome number by half
meiosis
the process of sperm cell development
spermatogenesis
the first stage of prophase 1 is _____________
leptotene stage
during this stage, individual chromosomes begin to condense into long strands within the nucleus
leptotene
occurs as the chromosomes approximately line up with each other into homologous chromosomes
zygotene
Prophase 1 stages
leptotene
zygotene
pachynema
diplotene
diakinesis
the homologous chromosomes separate from one another a little
diplotene
in this stage the homologous chromosomes separate further and the chiasmata terminalize
diakinesis
tetrads or homologous chromosomes move to the center of the cell
metaphase1
homogolous chromosomes pulled to opposite poles
anaphase 1
chromosomes cluster at opposite poles of cell and begin to decondense
telophase 1
in this phase the nuclear envelope breaks down and the spindle apparatus forms
prophaseII
chromosomes move to cell equator
metaphase II
produces four non-identical haploid cells
telophase II
