DNA is institute inward the nucleus. It carries the genetic data inward all eukaryotes.
How is deoxyribonucleic acid organized?
-its basic construction is the double helix
-this is in addition to therefore injure roughly proteins (called histones) to cast chromatin. Under an electron microscope, it looks similar beads on a chain. This is the cast that deoxyribonucleic acid is stored inward betwixt jail cellular telephone divisions
-during jail cellular telephone partitioning the deoxyribonucleic acid winds upward to a greater extent than tightly in addition to the chromatin coils on itself, looping in addition to coiling to cast thick rods called chromosomes, which are visible nether the lite microscope
Image from: http://themedicalbiochemistrypage.org/dna.html
What happens?
deoxyribonucleic acid is copied when it is uncondensed, in addition to therefore it condenses into chromosomes that convey 2 halves (each a re-create of the other). Each one-half is called a chromatid. Sister chromatids are identical. The betoken at which the deoxyribonucleic acid narrows in addition to the chromatids are connected is called the centromere. Each chromosome has many genes, each cistron defines a unmarried characteristic.
The seat out in addition to shape of chromosomes are species-specific. eg. Humans = 46 chromosomes, dogs = 78, pea = 14, fruit wing = 8
All sexually reproducing organisms convey 2 sets of chromosomes, i from each nurture (this is the diploid state). In humans a diploid jail cellular telephone has 46 chromosomes, one-half from the woman nurture in addition to one-half from the manlike individual nurture (23). The chromosomes which acquit the same variety of data are called homologous chromosomes.
Cell division
There are 2 types:
- mitosis (számtartó sejtosztodás): purpose is increment in addition to repair, 2 identical miss cells are produced
- meiosis (számfelező sejtosztodás): purpose is to hit gametes (sex cells) for reproduction, four genetically unlike cells are produced
The jail cellular telephone bike describes the typical bike of a somatic (body) jail cellular telephone that volition become through mitosis:
Image from: http://www.cdli.ca/courses/biol3201/unit02/unit02_org01_ilo02/b_activity.html
During the showtime increment phase, the jail cellular telephone merely grows in addition to carries out its normal functions. At a for certain point, the jail cellular telephone enters the synthesis phase, where the deoxyribonucleic acid is replicated.
DNA replication refers to the creation of some other deoxyribonucleic acid double helix using the showtime helix every bit a template. In gild for this to occur:
Once deoxyribonucleic acid replication has occured, the nucleus in addition to therefore has 2 copies of all of its deoxyribonucleic acid in addition to volition proceed to grow in addition to acquit out some normal functions, but it volition too ready for jail cellular telephone division, which is either mitosis or meiosis, depending on whether or non it is a jail cellular telephone that volition merely re-create itself, or a jail cellular telephone that is designed to hit gametes (eggs or sperm).
Mitosis is divided into four phases:
Prophase:
-chromatin condenses to chromosome
-nuclear envelope disintegrates in addition to disappears
-spindle (magorsó) forms
Metaphase:
-chromosomes job upward at the equator
Anaphase:
-chromatids are pulled to contrary poles of the cell
Telophase:
-cell plasma divides
-nuclear envelope reappears
(don't worry nearly the extra stages inward the icon below!!)
Image from: https://www.msu.edu/ robiemat/science.htm
Image from : http://imcurious.wikispaces.com/Midterm+Exam+2010+Review+P1
Meiosis occurs to hit haploid cells that volition endure gametes (sperm in addition to eggs).
It is a partitioning that reduces the chromosome seat out past times half. It is divided into meiosis I in addition to meiosis II
Meiosis I
Prophase I
-chromatin condenses to chromosomes
-chromosomes "find" their homologous pairs in addition to crossing over occurs
Metaphase I
--nuclear membrane disappears
-homologous chromosomes job upward at the equator in addition to attach to spindle fibres
Anaphase I
- chromosomes pairs are split every bit they are pulled to contrary poles
Telophase I
- jail cellular telephone plasma divides
- nuclear membrane reforms
Short interphase, amongst no deoxyribonucleic acid replication
Meiosis II
Prophase II
-chromosomes condense
- nuclear membrane disappears
-spindle forms
Metaphase II
-chromosomes job upward at the equator
Anaphase II
-chromatids are pulled to contrary poles of the cell
Telophase II
-cell plasma divides
-nuclear membrane forms
Image from: http://commons.wikimedia.org/wiki/File:Meiosis_diagram.jpg
So mitosis in addition to meiosis portion some characteristics, but are too unique inward many ways. The next diagram presents a comparing of the two. Be for certain to consider how they are similar in addition to how they are different.
Image from: http://bioactive.mrkirkscience.com/09/ch9summary.html
How is deoxyribonucleic acid organized?
-its basic construction is the double helix
-this is in addition to therefore injure roughly proteins (called histones) to cast chromatin. Under an electron microscope, it looks similar beads on a chain. This is the cast that deoxyribonucleic acid is stored inward betwixt jail cellular telephone divisions
-during jail cellular telephone partitioning the deoxyribonucleic acid winds upward to a greater extent than tightly in addition to the chromatin coils on itself, looping in addition to coiling to cast thick rods called chromosomes, which are visible nether the lite microscope
What happens?
deoxyribonucleic acid is copied when it is uncondensed, in addition to therefore it condenses into chromosomes that convey 2 halves (each a re-create of the other). Each one-half is called a chromatid. Sister chromatids are identical. The betoken at which the deoxyribonucleic acid narrows in addition to the chromatids are connected is called the centromere. Each chromosome has many genes, each cistron defines a unmarried characteristic.
The seat out in addition to shape of chromosomes are species-specific. eg. Humans = 46 chromosomes, dogs = 78, pea = 14, fruit wing = 8
All sexually reproducing organisms convey 2 sets of chromosomes, i from each nurture (this is the diploid state). In humans a diploid jail cellular telephone has 46 chromosomes, one-half from the woman nurture in addition to one-half from the manlike individual nurture (23). The chromosomes which acquit the same variety of data are called homologous chromosomes.
Cell division
There are 2 types:
- mitosis (számtartó sejtosztodás): purpose is increment in addition to repair, 2 identical miss cells are produced
- meiosis (számfelező sejtosztodás): purpose is to hit gametes (sex cells) for reproduction, four genetically unlike cells are produced
The jail cellular telephone bike describes the typical bike of a somatic (body) jail cellular telephone that volition become through mitosis:
During the showtime increment phase, the jail cellular telephone merely grows in addition to carries out its normal functions. At a for certain point, the jail cellular telephone enters the synthesis phase, where the deoxyribonucleic acid is replicated.
DNA replication refers to the creation of some other deoxyribonucleic acid double helix using the showtime helix every bit a template. In gild for this to occur:
1. The deoxyribonucleic acid double helix begins to unwind or unzip at i halt to cast a replication fork. Unwinding requires the assistance of an enzyme called a helicase.
2. Enzymes called DNA polymerases bind to the unmarried strands of DNA. They in addition to therefore proceed to "read" the template strand (in the 5' to 3' direction) in addition to add together complementary nucleotides. Since the polymerase alone travels inward i direction, it volition motion to a greater extent than rapidly along the leading strand, but on the lagging strand it volition attach at the fork in addition to motion toward the end, until it meets upward amongst a previously formed deoxyribonucleic acid strand fragment, in addition to therefore it volition detach in addition to reattach at the continuously unwinding replication fork. The fragments that are created inward this agency are called Okazaki fragments. They are "glued" together amongst the assistance of enzymes called ligases.
The halt effect is two semi-conservative miss double helixes- meaning that each double helix contains i strand from the master in addition to i strand that is new.
If y'all desire to reckon a video: http://www.youtube.com/watch?v=teV62zrm2P0
Once deoxyribonucleic acid replication has occured, the nucleus in addition to therefore has 2 copies of all of its deoxyribonucleic acid in addition to volition proceed to grow in addition to acquit out some normal functions, but it volition too ready for jail cellular telephone division, which is either mitosis or meiosis, depending on whether or non it is a jail cellular telephone that volition merely re-create itself, or a jail cellular telephone that is designed to hit gametes (eggs or sperm).
Mitosis is divided into four phases:
Prophase:
-chromatin condenses to chromosome
-nuclear envelope disintegrates in addition to disappears
-spindle (magorsó) forms
Metaphase:
-chromosomes job upward at the equator
Anaphase:
-chromatids are pulled to contrary poles of the cell
Telophase:
-cell plasma divides
-nuclear envelope reappears
(don't worry nearly the extra stages inward the icon below!!)
Image from: https://www.msu.edu/ robiemat/science.htm
Image from : http://imcurious.wikispaces.com/Midterm+Exam+2010+Review+P1
Meiosis occurs to hit haploid cells that volition endure gametes (sperm in addition to eggs).
It is a partitioning that reduces the chromosome seat out past times half. It is divided into meiosis I in addition to meiosis II
Meiosis I
Prophase I
-chromatin condenses to chromosomes
-chromosomes "find" their homologous pairs in addition to crossing over occurs
Metaphase I
--nuclear membrane disappears
-homologous chromosomes job upward at the equator in addition to attach to spindle fibres
Anaphase I
- chromosomes pairs are split every bit they are pulled to contrary poles
Telophase I
- jail cellular telephone plasma divides
- nuclear membrane reforms
Short interphase, amongst no deoxyribonucleic acid replication
Meiosis II
Prophase II
-chromosomes condense
- nuclear membrane disappears
-spindle forms
Metaphase II
-chromosomes job upward at the equator
Anaphase II
-chromatids are pulled to contrary poles of the cell
Telophase II
-cell plasma divides
-nuclear membrane forms
Image from: http://commons.wikimedia.org/wiki/File:Meiosis_diagram.jpg
So mitosis in addition to meiosis portion some characteristics, but are too unique inward many ways. The next diagram presents a comparing of the two. Be for certain to consider how they are similar in addition to how they are different.
Image from: http://bioactive.mrkirkscience.com/09/ch9summary.html
Komentar
Posting Komentar