Mr. Mateki Third test Flashcards
What sort of cell does meiosis start with, and what sort of cells does it end up with.
Starts with a diploid cell and ends up with 4 haploid cells.
After the original cell, every cell after that is haploid
Interphase in meiosis 1
cells undergo a round of DNA replication, forming duplicate chromosomes
Prophase 1 in meiosis 1
each chromosome pairs with its corresponding homologues chromosome to form a tetrad. Crossing over of genes occurs
Tetrad
a diploid cell with two sister chromatids
Crossing over
after tetrads are made, crossing over occurs. The chromatids of the homologous chromosomes cross over one another. Crossing over produces new combinations of alleles on each chromatid.
Metaphase 1 in meiosis 1
spindle fibers attach to the chromosome
Anaphase 1 in meiosis 1
the spindle fibers pull the homologous chromosomes to opposite ends of the cell
Telophase 1 and cytokinesis in meiosis 1
nuclear membranes form. The cell separates into two cells.
What is the end product of meiosis
at the end of Meiosis II 4 cells are produced, each with 23 chromosomes. All are different, and will never be produced again.
Independent assortment
the variation of chromosomes, or genetic information, during sex cell division. Allows for genetic differentiation in offspring.
Prophase II in miosis II
meiosis I results in two haploid daughter cells, each with half the number of chromosomes as the original cell
Metaphase II in miosis II
the chromosomes line up in a similar way to the metaphase stage of mitosis
Anaphase II in miosis II
the sister chromatids separate and move towards opposite ends of cell
Telophase II and cytokinesis in miosis II
meiosis II results in 4 haploid daughter cells
In which stage of meiosis do chromosomes divide?
Meiosis 1
Differentiation
how cells become specialized
Are differentiated cells different from the original cell that produced it
Yes
How are differentiated cells specialized
Differentiated cells are specialized to perform certain jobs
Totipotent
having the ability to develop into all the tissues of the body
Pluripotent
able to develop into all the body’s cell types, but not capable of developing into the tissues surrounding the embryo
Embryo
an organism in its early stage of development
Stem cells
unspecialized cells from which differentiated cells develop.
Blastocyst
a human embryo forms into a blastocyst, a hollow ball of cells with a cluster of cells inside known as the inner cell mass
Blastocyst
an ion pump that creates electrochemical gradient. In the plasma membrane
U
Uracell
Polymerase
reads, transcribes, and replicates DNA
Genetics
the scientific study of heredity
Fertilization
the process in sexual reproduction in which male and female reproductive cells join to form a new cell
Trait
a specific characteristic of an individual
Gene
a factor that is passed from parent to offspring
Allele
one of a number of different forms of a gene
Principle of dominance
states that some alleles are dominant and others are recessive
In which stage of meiosis do chromatids divide?
meiosis II
