Bio #3 Flashcards
what is mitosis?
a phase in the cell cycle in which the genetic material is divide and two genetically similar nuclei are produced, somatic cell division.
what type of reproduction happens in mitosis?
Asexual reproduction, fast, efficient, some # of offspring
how many division are there in Mitosis, and how many cells are formed per cycle?
One division occurs during mitosis
Two diploid cell 2n are formed per cell cycle,
when is DNA copied in mitosis?
DNA is copied during interphase
does Pairing of homologous chromosomes occur?
Pairing of homologous chromosomes does not occur
are daughter cell identical?
The daughter cells are genetically identical Only occurs in body cells, Growth and repair
what is cell division?
A cell divides into two new cells. Each cell is identical to the original cell.
what is sister chromatid?
one of two copies of a chromosomes
what is the centromere?
The point where two sister chromatids of a duplicated chromosome are attached .
what are spindle fibers?
proteins that orderly distribution of chromosomes to a daughter cell
what is the somatic cell?
a cell that’s part of the body
In mitosis what happens in interphase?
The cell is growing 90% of the time
The cell organelles are duplicating
DNA duplicates and condenses from chromatin to chromosomes
how many cells are there when the cell duplicate?
Each cell has 23 chromosomes
When it duplicate the 23 replicated to 46
When the daughter cell splits each new cell has 23 chromosomes again.
In mitosis what happens in prophase?
the nuclear membrane disappears
The centrioles move to the opposite side
Spindle fivers are formed from centrioles
Chromatin becomes visible chromosomes
Chromatin tightens, and the chromosome are X shaped.
In mitosis what happens in metaphase?
The chromosomes line up in the middle of the cell
To make sure each cell has the correct copies of chromosomes
One of the shortest phases
In mitosis what happens in Anaphase?
the chromosomes are pulled apart by the spindle fibers
DNA chromosomes are split equally 23 to each side
They are pulled to opposites side of cell.
in mitosis what happens in telophase?
a nucellar membrane begins to form around each set of chromosomes
The cytoplasm begins to divide
new nuclei develop
Spinder fibers disappear
In mitosis what happens in cytokinesis animal?
Animal: cell membrane pinch together in the center, Organelles separate into equals parts, Two new daughter cells are produce exact of the initial parent cell
in mitosis what happens in cytokinesis plant?
Plant: Cells plate forms, New cell wall laid down between membranes
what happens in Meiosis?
germ cells a phase in the cell in the cell cycle that involves division of the genetic material
it results in the production of four haploid daughter cells, and it occurs in germ cells of ovaries and testes,
how many set of division’s occur in meiosis?
Two sets of divisions occur during meiosis: meiosis 1 and 2
when is DNA copied in meiosis?
DNA is copied before meiosis 1
when does pairing of homologous occur?
Pairing of homologous chromosomes occurs during prophase 1
How many haploid cells happen per cycle?
Four haploid daughter cells n per cell cycle, T
is the daughter identical?
The daughter is not genetically identical,
what type of cells does meiosis occurs?
Meiosis occurs only reproductive cells
what does meiosis involved?
Meiosis is involved in the production of gametes and providing genetic variation in organisms.
what is gamete?
male or female haploid
what is zygote cell?
a diploid cell formed by the fusion of sperm and an egg
what is haploid?
having one set of chromosomes n
what is diploid cell?
having two sets of chromosomes 2n
what is Homologous chromosomes?
one pair of chromosomes that share similar characteristics
what a human genome?
has 23 pairs of chromosomes (46 in total)Each chromosomes is essential for survival except the y chromosome
what is karyotyping?
the process where chromosomes are stained and examined under a microscope to look at chromosomes shape and number
what is sex determination?
23 pairs is the xy and this determines sex. Male has x y and females has x x chromosomes
Atypical karyotypes?
Aneuploidy: random mistakes in meiosis
It has an extra chromosome or is missing one
aneuploidy is diagnosed by karyotyping.
in meiosis what happens in interphase?
Interphase: at the end of interphase chromone have been replicated, Chromatin begin to condense
what happens in Prophase 1?
homologous chromosomes begin to form pairs
This is called crossover, Segments of chromosomes are exchanged between pairs.
what happens in Metaphase 1
two sister chromosomes of two sister chromatids line up, They line up in pairs in the middle of the cell, The spindle fibers form
what happens in Anaphase 1?
homologous chromosome separate and pulled to opposite side by the spindle fibers, Each homologous chromosome still consist of two siter chromatids
what happens in telophase 1?
the spindle fibers break down
the nuclear membrane forms around two new nuclei Each of the two daughter cells have a complete set of homologous chromosome
the cell divides to produce two daughter cell
what happens in prophase 11?
chromatin tightens, Spindle fibers attach to the chromosomes, The nuclear membrane dissolves.
what happens in metaphase 11?
centromeres of chromosomes line up randomly in the middle of the cell.
what happens in anaphase 11?
centromeres split, Sister chromatids separate and move to opposite sides of each cell
what happens in telophase 11?
four nuclei from around the chromosome, Spindle fibers breakdown, Cell divides
what happens in Cytokinesis?
break into four cells
what are their products?
Four haploid gametes are produce which a single set of chromosomes Each nucleus contains haploid number of chromosomes.
what are Klinefelter syndrome?
Klinefelter syndrome: extra x in male ( xxy)
what is turner syndrome?
Turner syndrome: single x in female
what is down syndrome?
Down syndrome: Trisomy, extra chromosome 21
what is crossing over?
crossing over: during prophase 1 it shuffels the gene so no one is the same
what is nondisjunction?
: at metaphase siter fail to separate and both sister pull to one side.
what is Monosomy?
Offspring having one less chromosomes
Trisomy offspring having one more chromosome
what is independent assortment?
Metaphase their is no set order, it pulls to random collection when the spindle fibers pull
what is synapsis?
Synapsis prophase 1 chromosome pair up and stick together
what is the tetrad?
Tetrad a group of four cells during meiosis.
what is Autosomes?
any chromosome that not a sex chromsome
what is a gene?
DNA that is inherited trait
why would drugs be effective at batting cancer?
if the spindle fibers separate the cell can’t grow
difference between mitosis and meiosis?
mitosis is asexual
meiosis is sexual
mitosis is somatic cell
meiosis is germ cell
mitosis has one cell cycle
meiosis has two cell cycle
what is responsible for genetic diversity and this is why sibling don’t look the same?
crossing over happens in metaphase/ anaphase
bc there is no set order how the crossing over happens and how the spindle fiber pull apart
