INTRODUCTION TO GENETICS AND CELL DIVISION
UNDERSTANDING GENETICS
Genetics broadly discusses:
1) the structure of genetic material, including: genes, chromosomes,
DNA, RNA, plasmids, episomes, and transposable elements,
2) reproduction material genetic, includes: reproduction cell,
replication DNA, reverse transcription, rolling circles replication,
cytoplasmic inheritance, And Mendelians inheritance,
3) Work material genetic, includes: room scope material genetic,
transcription, modification posttranscription, code genetic, translation,
draft one genes one enzymes, interaction Work gene, control Work
gene on prokaryotic, control Work gene on eukaryotic, control genetic
immune response, genetic control of cell division, sexual expression,
change material genetic,
4) change material genetic, includes: mutation, And recombination,
5) genetics in population, And
6) engineering material genetic
LAW MENDEL CLASSIC
J.G Mendel is person Which First time put forward One mechanism
inheritance characteristic decrease through experiment in field
genetics.
Based on this experiment, the scientific theory of genetics at that
time, namely The Blending Theory of Inheritance No Correct.
Before Mendel do testCrossing with pea plants (
Pisum sativum
)
experts already have thinking about exists life Which sustainable,
Which bring factor descendants from generation to generation.
Mendel's basic ideas were then used as the basis For obtain traits
Which desired with do hybridization. Based on his services in do
studies genetics with do crossMendel was nicknamed the father of
genetics in peas.
Mendel's laws of inheritance are laws that regulate the inheritance
of traits in a way genetic from One organism to his descendants.
Law the consists fromtwo part :
1
.
Mendel's First Law (law of separation or segregation) The content
of the law segregation :
On time taking place formation gametes,
every install gene willsegregated to in each gametes are formed.
2
.
Law Second Mendel (law pair in a way free or independent
assortment) Contents from law partner free :
Segregation
something partner gene No depends on the segregation of other
gene pairs, so that in gametes gametes Which formed will happen
election combination genes in a way free
.
Mendel's Law I states that inheritance of traits from both parent
genes which is a pair of alleles that will undergo separation. The
separation will be received by each gamete with the amount of
one parent gene it received.
Mendel's Law I can be called the Law of Free Segregation which
states inheritance characteristic parent on formation gametes
descendants will through divisiongene parent ie happen on cross
monohybrid.
Monohybrid is a cross between two individuals of the same species
but with one characteristic different. Monohybrids produce
uniform first offspring (F1). Descendants First (F1) monohybrid
have phenotype Which similar with its parent Which dominant If
dominance looks fully. Separation allele happens when
descendants First (F1) heterozygous form gametes Which will
cause gametes just have Wrong one allele just.
CHROMOSOME
1.The shape of chromosomes known so far is linear. X sex
chromosome straight and the Y chromosome is shaped like an
anchor. The shape of this chromosome only covers chromosome
on core cell eukaryotes.
2.There is various form chromosomes in groups of living things.
Chromosome shape in virus groupsdiverse. Some viruses are rod-
shaped (linear), some are circular or ring-shaped, Some viruses
are linear but in certain circumstances they are circular (e.g.
viruses phage
λ
).
3.The shape of prokaryotic chromosomes is circular or double-
stranded DNA ring. For example, E. coli has a ring shape. The
shape of any eukaryotic chromosome the amount is shaped linear
or rod. Shape chromosome on organelle mitochondria And
chloroplast is circular or ring like on group prokaryotes.
4.Chromosomes have various shapes in stages metaphase during cell
division. Chromosome shapes vary based on location the
centromere; some are metacentric, submetacentric, acrocentric,
etc telocentric.
5.The centromere is the indented area on the chromosome and is
also the location kinetochore (place linked spindle fiber moment
division cell). Chromosome It is a solid structure consisting of
protein and DNA. Chromosomes have structure unique as form
packaging gene. With say other in in chromosomeThere are gene
loci, namely the position and position of a gene on the
chromosome.
6.Gen That Alone is range DNA or sequence DNA Which determine
something proteins. According to genetic dogma, "one gene, one
polypeptide". For one type chromosome can contain thousand
gene like on chromosome number One man.
7.Human Genomes Projects, chromosome number One man
arranged by 3,141 gene And 1,000 in among them is gene Which
new found.Chromosome 1 has up to twice the number of genes as
chromosomes in general And compile around 8 percent genome
man.
8.Form chromosome with form chromatids the is form chromosome
on moment stage division cell. At the stage where the
chromosomes duplicate in the growth mechanism or inheritance.
Good through meiosis nor mitosis.
AMOUNT CHROMOSOME
The number of chromosomes for various viruses is one molecule
DNA or RNA Good strand double nor strand single, linear or
circular. The number of bacterial chromosomes is one.
Bacterial chromosomes are single-stranded DNA molecules
circular doublets associated with certain proteins. The number of
chromosomes of the species eukaryotes various Good animal nor
plant, diploid nor monoploid.
The same number of chromosomes for viruses, prokaryotes and
living things eukaryotes No indicators from similarity species.
Amount chromosome mitochondria And chloroplast only One
circular fruit .
Haploid is a condition in which an individual does not have a
partner chromosome because only have genome single.
Chromosome haploid can doubled Which will produce individual
homozygous new. Cell haploid there is in gametes which can
produce diploid characteristics because if the gamete cells are
female The fertilized male germ cells will fuse and develop into a
zygote Which bersifal diploid .
Diploid is condition opposite from haploid Which where on diploid
there is two set chromosome(2n). The diploid condition is found
in most multicellular organisms. An example of a diploid
organism is a fern which has a large number of chromosomes
somatic around 58.
PART CHROMOSOME
1.The parts of the chromosomes described here are the
chromosomes found in core cell eukaryotic during metaphase
mitosis. Part main chromosome depicted as proteins Which
envelope DNA. Depiction chromosome like This before found
microscope electron.
2.The main part of eukaryotic chromosomes is the
genome/DNA/RNA. So part Which principal is sour nucleic.
Proteins No part main. So function chromosome is bring factor
descendants on part its genome No the protein.
3.In fact, there is no outer membrane covering the chromosomes,
nor do they existthe part called the matrix because in reality it is
not the protein that covers it DNA but DNA that is wrapped
around histone proteins. Next, the chromosomes are divided into
parts arm and centromere.
DIVISION CELL
Division Cell on Acellular
Viruses and retroviruses are classified as acellular living creatures
outside the group organism prokaryotic And eukaryotic. Entire
creature life And virus as well as retroviruses do process division
cell For multiply self. Propagationcell virus carried out in cells the
host.
Division Cell on Prokaryotic
Prokaryotes (bacteria) reproduce through a type of binary fission,
namely fission become half. Most bacterial genes are found on a
single chromosome consists of circular DNA and protein.
Although bacteria are simpler than cells eukaryotic, but its
genome replication is regular and distribution of copies in the
same way to both cells children are still difficult understandable.
Division Cell on Eukaryotic
Creature life eukaryotic Which breed in a way sexual Good animal,
man, plant, do reproduction For maintain the species. Body
creature life grow Because exists division cell. Gametes formed
through cell division. Cell division or what is usually called cell
reproduction consists on 2 type that is in a way mitosis And
meiosis, ongoing reproduction This through something stages
(phase), on stage sake stage happen change from the position of
the chromosome, so based on the position of the chromosome
this can be done seen phases its division.
Cell division includes two main processes, namely mitosis and
cytokinesis. Cell division that actually forms two cells is called
cytokinesis. Before cell eukaryotes split the nucleus must
experience mitosis that is something divisioncomplex Which in a
way appropriate spread group chromosome Which step to each
nucleus cell child. Mitosis ensure that each cell The new one
contains chromosomes in the same quantity and type withWhich
found in cell original parent.
In general, the cell cycle consists of two periods, namely
interphase (includes phaseG1, S, and G2. The G1 phase is the pre-
synthesis period, the S phase is the period synthesis, and G2 is the
post-synthesis phase of the two phases of cell division consisting
over the phases of mitosis and cytokinesis. The mitosis phase
consists of several phases, namely phases prophase, phase
metaphase, phase anaphase, dn phase telophase. In between
prophase And metaphase,Some authors suggest the existence of a
prometaphase phase. Division phases mitosis on is a phase Which
extreme.
During period interphase, chromosome No looks caused Because
materialchromosome in form threads chromatin, And components
makrpo the molecule distributed in the core. During cycle cell
These changes occur, especially in the chemical components of
cells such as DNA, RNA, and various types of proteins. DNA
duplication takes place over a period of time interphase called the
synthesis phase or S period. The synthesis period is preceded by
period G1 and followed by period G2.
During cell division, the nucleus undergoes a series of changes
Which very complex, especially changes content the main thing is.
On moment cell division progresses, the nuclear membrane and
nucleus become invisible and substance chromatin experience
condensation become chromosome.
Division cell happen through stages certain. Stages This aim For
arrange parent genetic information that will be passed on to
daughter cells. Based on there whether or not certain stages in cell
division, cell division is divided become three, that is amitosis,
mitosis, And meiosis .
AMITOSIS
Division amitosis is division cell Which taking place without
involves certain phases commonly found in mitosis and division
meiosis.
Amitosis division is direct or so-called cell division also with simple
division preceded by nuclear division without preceded formation
thread spindle, apparition chromosome, smelting nuclear
membrane and other characteristics.
The process that occurs in this division is cells Children inherit the
characteristics of their parents so that amitotic division produces
offspring Which characteristic cell his son identical with cell its
parent.
Division amitosis taking place relatively spontaneous And found on
a number organism prokaryoticlike bacteria and blue green algae.
MITOSIS
Mitosis is the process of nuclear division in eukaryotic cells
conventional divided become five stage.
Mitosis maintain amount chromosomes by placing the replicated
chromosomes in a balanced mannereach daughter nucleus.
In mitosis, chromosomes are in numbers Which still during
process division. During mitosis, every stages must taking place
with perfect, Because lost chromosome during process division
can cause changes in the mature plant.
Stages during mitosis is: interphase, prophase, metaphase,
anaphase and telophase.
Prophase is stage First mitosis, moment chromatin condensed,The
mitotic spindle begins to form, and the nucleolus disappears, but
the nucleus remains intact.
Prometaphase, the second stage of mitosis when discrete
chromosomes are composed on chromatids you Which appear,
And microtubules attached to kinetochore chromosome.
metaphase, stage third mitosis moment spindle Already complete
Andchromosomes attached to microtubules on kinector as well as
lined up in metaphase plate. This is the longest stage of mitosis,
around 20 minutes.
Anaphase is stage Mitosis most short, a number of minute. Proteins
cohesin splitseparate chromatids you in a way suddenly. Second
chromosome move towards each Pole.
Cell elongated moment Microtubules non kinetochore push to
different poles. Telophase has no mitotic spindle, two daughter
nuclei formed in cells, each having identical chromosomes.
Chromosome becomes less condensed. Cytokinesis Cytoplasmic
division usually occurs taking place Enough Far on end Telophase.
So that Cell Saplings appear not longafter mitosis ends.
Cytokinesis in animal cells occurs through unfolding divides the
mother cell into two with a contractile ring of actin filaments.
Cytokinesis plants occur because cell plates form in the middle of
the cell and grow up the layout is working properly membrane
cell plasma parent.
SIGNIFICANCE MITOSIS
This extraordinary regulation of the cell division process
guarantees each cell The child will receive chromosomes in
exactly the same number and type as Which owned by cell its
parent.
Then every from organism multicellular have amount And type
chromosome Which Certain The same with cells other. Ifone cell
have to accept chromosome which is the amount less or more
than the number of chromosomes that should be due to an
abnormality in cell function during the division process, cells will
be produced that show signs abnormal And possibility No capable
life.
Reality that cell containthe genetic information necessary for each
trait of the organism to be capable explains why a single cell taken
from a mature plant fully differentiated and grown under
conditions suitable for culture cells, will be able to develop into a
complete new plant.
MEIOSIS
Meiosis is modified cell division in organisms that reproduce
sexually, consisting of two cell divisions but only one time
replication DNA.
Meiosis is process division cell gametes For produces haploid cells,
the number of chromosomes is half the number of chromosomes
of the cell original. Meiosis occurs twice, first the cells will
experience a reduction in number chromosomes (Meiosis I) and
sister chromatids separate, this process is identical to mitosis
(Meiosis II).
These two processes of cell division (mitosis and meiosis) are
basically identical experience stages Which The same during
process division like chromosome thickens, the chromosomes are
in the middle of the cell and then move towards pole And Finally
split.
Difference both of them is on How chromosome interactions
homologous. Produces half the chromosomes of its parent.
Interphase in meiosis occurs only once, namely at the beginning
of meiosis I, so replication DNA only happen One time although
meiosis experience two time division.
Prophase I on meiosis shared become five stage that is Leptonema,
Zigonema, Pakinema, Diplonema and Diakinesis. Leptonema
Chromosomes start condensed.
Zigonema, couples chromosome homologous meet And held
together by a ribbon-like protein structure called the
synaptonemal complex (bivalent). Pakinema, synapses are formed,
one of the non-sister chromosomes (tetrad) carry out crossover.
The part that carries out the crossing over is called chiasmata.
Diplonema, synaptonema complex begins to disappear, chiasmata
are still visible. Diakinesis, chromosomes are maximally
condensed, the nuclear membrane disappears and spindle mitosis
formed.
Prophase I, chromosome condensed, And each chromosome
homologous pair. Crossing over occurs randomly. Every couple
homologues have 1 or more chiasmata (where crossing over
occurs) Membranes Nucleus fragmented.
Metaphase I, Homologous Chromosome Pairs are on the
Metaphase Plate. Second Chromatids from One homologous,
attached to One Microtubules Kinektor from Wrong One Pole
Spindle.
Anaphase I, decomposition Cohesion, result Homolog separate.
Homolog move to pole Which different.
Telophase I, Each Saplings cell own set haploid complete or
called haploid sisters chromatids. Part sisters chromatids has
modified, consequence Move Cross. Chromosome Nodecomposes,
for phase II Meiosis followed by first cytokinesis.
Prophase II, Spindle formed, Chromosome recombinant haploid,
membrane nucleus is lost.
Metaphase II Chromosome is at on Plate Metaphase.
Anaphase II,Chromatids can be separated Because decomposition
proteins Which combinechromatids you in centromere.
Telophase II, Nucleus formed, Chromosome decompose become
chromatin, Produce 4 cell sapling haploid not replicated.
Each from fourth cell sapling different in a way genetic with cell
saplingother And also cells parent next cytokinesis second.
THE RELATIONSHIP OF MEIOSIS DIVISION WITH
MOVEMENTCROSS
In prophase 1, homologous chromosomes form pairs. pairs are
called bivalents. The process of pairing homologous
chromosomes is calledsynapse. Then every member bivalent split
elongated so that formed 4 chromatids.
Fourth chromatids on One bivalent named tetrad. During synapse
here it is can happen move cross (crossing over). Move cross isthe
event of exchanging segments of chromatids in a tetrad and
crossing over happen between chromatids Which No pair.
Process final This coverssplitting and rejoining only two of the four
threads at the point Anything on that chromosome .
The existence of crossing over can increase the genetic variation of
offspring, namely If 2 or more genes are on one chromosome,
crossing over is possible produce gametes Which own gene Which
on initially No There is, Because happen move cross so produce
gametes Which own chromosome from type recombinant.
DIVISION MEIOSIS AND NONDISJUCTION
Failure to separate (Nondisjunction) is an event that does not
separate pair chromosome during division cell (meiosis). Matter
This happen during formation gametes (gametogenesis) ie
moment taking place meoisis.
Pairs of chromosomes or homologous chromosomes in the inner
gametangium mother cellscircumstances normal will separate so
that gametes own half from amount chromosome owned by
individuals.
However thereby on phase anaphase I can happen incident No
separate it partner chromosome Because influence certain so that
still get together as a couple. This event is called normal
nondisjunction happen on phase anaphase I.
Incident failed to separate differentiated on fail separate primary
And fail separate secondary. Failseparate primary occurs in first
derivative.
F ACTORS WHICH INFLUENCE CYCLE CELL
Frequency mitosis on networks Which different And on species
Which different very diverse. On condition Where food,
temperature And pH optimal so long cycle cell (time generation)
from every type cell is constant. On condition which is less
favorable, the cell cycle will be slow, namely the generation time
longer.
It is still not possible to speed up the cell cycle and create cells
grow fast even though it is only through experimentation. Looks
that long cycle cell is time Which needed by cell For carry out a
number of program consists from two part that is: One must do
replication materialgenetic in in chromosome And Which other is
doubling all over compilercell Which needed in its growth.
Bbacteria can split every 20 minute. On marrow Every second,
human bones produce 10 million red blood cells, which means
every second must happen 10 million mitosis.
Cells Which coating channel digestion And cell-Cells found in the
reproductive layer of the skin divide very quickly throughout his
life. In contrast, cell division in the central nervous system usually
stops on some first month from his life.
In almost all animal cells, substances are produced that regulate
entry cells into S phase or M phase depending on stimulation by
growth regulatory substancesWhich there is in in blood.
Factor growth This is proteins Which smalland acts specifically on
some cell types and not on others. Like for example, factor growth
nerve needed for mitosis cells nerve sympathetic.
The substance that inhibits mitosis is called calone, which controls
the work factor growth. Kalone Also very typical And only
influence type network Where substance That generated. For
example just, Kalone Which generated by cells skin hinder
mitosis cells skin neighbor. It's broken cell skin It is thought
that because Kalone is not produced enough, the surrounding
cells are damaged this is despite this inhibition.
Cells begin to divide to produce tissue new For cure wound. If cells
that Healthy has Enough the amount, cell- cell Then produce
Kalone For hinder mitosis next And stop the process healing
wound.
Cycle cell Also influenced by drugs certain. Colchicine is a drug
used to restrain the division of eukaryotic cells. this substance
bonded with proteins microtubules And follow as well as in
function spindle mitosis Whichnormal.
Chromosome No can separate in a way appropriate And move to
direction end cellthe opposite. The result is that cells can end up
with a group chromosome Which excessive. Cell plant can life
although treatedwith colchicines.
Antibiotics such as streptomycin and tetracycline prevent mitosis
indirectly by inhibiting protein synthesis in prokaryotic cells.
Matter this prolongs the G1 phase of the cell cycle. Several
medications are used in treatment cancer can withhold One or a
number of enzyme including synthesis DNAAnd division cell.
To carry out various chemical reactions that are important for
survival To live, cells must be able to maintain a proper internal
environment. Cells must capable arrange its composition Alone,
create condition Which constant even though conditions outside
the cell change.
