Cell Division Flashcards
Cell division is…
The ability to grow and reproduce
Reproduction occurs as binary fission in…
Prokaryotes
In single cell organisms, Mitosis is a means of…
Asexual production
In multi-cellular organisms, Mitosis…
Causes growth by increasing the number of cells
Replaces lost cells and repairs
Meiosis is sexual reproduction that involves donation of genetic information from…
(2) parents
Each parent can only donate half of the genome.
Meiosis occurs…
Prior to sexual reproduction.
Generates gametes with half of the genome
Egg and spermicide join fertilization
Eukaryotic cells…
Pass through different stages between the time they are born and the time they divide again
Interphase
DNA replication occurs (in the nucleus)
Two events of cell division…
Mitosis and cytokinesis
Cytokinesis
Divides the cytoplasm into (2) new cells (cell-splitting)
Animal cells pinch into (2)
Plant cells-plate is formed
(4) phases of Mitosis
Prophase
Metaphase
Anaphase
Telophase
Prophase
Nuclear membrane breaks down and centrioles line up
Metaphase
Chromatids line up at the center
Anaphase
Chromatids pulls apart
Telophase
Nuclear membrane reforms
Cells gather information about themselves and their environment in order to…
Decide whether or not to divide
Determination is
The process a cell goes through to select which gene it will express
When the cell is fully developed into a specific type of cell, it is said to be
Differentiated
Normal body cells have (2) sets of chromosomes
Haploid
Gametes have (1) set of chromosomes
Haploid
Homologous chromosomes….
Have the same order of genes along their DNA
Are the same size
Meiosis-gamete production…
Involves (2) cell divisions
Produces (4) haploid cells
Meiosis 1 is…
The first division
Meiosis II is…
The second division
Replication happens before meiosis I, but not again before meiosis II
Five factors of genetic diversity
Mutation Crossing-over Segregation Independent assortment Fertilization
Mutations
Changes in the nucleotide sequence of DNA
Creates new alleles
New alleles lead to new forms of proteins
Increases genetic diversity
Crossing-over
The exchange of equivalent portions of DNA between homologous chromosomes (during meiosis I)
Allows new combinations of genetic information to occur
Segregation
Alleles on homologous chromosomes separate during anaphase I
Independent assortment
How pairs line up on the equatorial plate (center) during cell division can lead to different combinations of gametes
Fertilization
Gametes join randomly, combinations of alleles is nearly infinite
Loss of diversity
Genetic drift occurs when specific genes are not passed on through sexual reproduction
