Meiosis Flashcards
Genetics
Biological study of inheritance
Gamete
Reproductive Cell with half the number of chromosomes
An organism with two parents…
Must inherit a single copy of genes from each parent.
Meiosis is
The first step of sexual reproduction
Diploid Cell
A cell with both sets of homologous chromosomes
Haploid Cell
A cell with both sets of chromosomes
Somatic Cells are
Diploid cells
Gametes are
Haploid Cells
Gametogenesis is
The formation of sex cells (gametes)
Oogenesis is
Formation of egg cells in females
Spermatogenesis
Formation of sperm cells in males
How many phases of Meiosis are there?
2
What is the difference between Meiosis 1 and 2?
Meiosis 1 seperates homologous chromosomes, Meiosis 2 separates the replicated chromosomes (just like in Mitosis)
Prophase 1
The Homologous chromosomes link to form a tetrad, and crossing over bits of DNA over the chromatids occurs.
Metaphase 1
The tetrad is moved to the middle and spindle fibers attach.
Anaphase 1
The tetrad is seperated with genetically different chromosomes on both sides.
Telophase/Cytokinesis 1
The nucleus reforms over the two chromosmes on either side, and forms into two genetically different daughter cells.
At this stage, are the cells diploid or haploid?
Haploid, after Cytokinesis 1
Prophase 2
No interphase, the nucleus breaks down leaivng the chromosme exposed.
Metaphase 2
The replicated genetically different chromosome lines up in the middle, spindle fibers attach to the centroid.
Anaphase 2
The chromosome is pulled apart, with the sister chromatids moving to opposite sides of the cell.
Telophase/Cytokinesis 2
Nucleus reforms over the chromosomes, leaving 4 spermatids (M), or an ovum (F).
What process develops spermatids into sperm cells?
Differentiation
Why is only one egg produced during meiosis in females?
Because the resources must be allocated to one, so the other three (polar bodies) die to prioritize what will soon be the egg.
