ch.11 cell division, meiosis, and sex Flashcards
What is the difference between prokaryotic and eukaryotic chromosomes?
The difference between prokaryotic cells and eukaryotic cells are the prokaryotic cells attach its DNA to a specific point on the cell wall, which is where DNA replication will occur. In addition, the long double-stranded DNA that it produces called a chromosome is circular. In eukaryotic cells, there is no cell wall, which allows DNA to initiate replication at many points of origin. The chromosomes are also linear.
What happens inside a growing eukaryotic cell during the G1 phase, S phase, G2 phase of the cell cycle.
G1 phase: cell needs to double in size before it can divide, which requires that it synthesizes double the proteins it needs just to maintain itself. To do so, the cell undergoes very active transcription and translation
S phase: cell replicates DNA
G2 phase: active protein synthesis (transcription and translation) of proteins specifically needed to perform mitosis/cell division
What is the purpose of mitosis?
to divide the chromosomes in eukaryotes to create 2 exact replicas of a cell for regeneration
What is the purpose of meiosis?
to create cells called gametes that takes 2 different cells into a unique cell that has the combined properties of 2 conjoined cells, also known as fertilization
In what ways are the processes of mitosis and meiosis the same?
*both have PMAT (prophase, metaphase, anaphase, telophase)
*both are forms of cell division for eukaryotic cells
*both copy their DNA once before cell division
*both start off with diploid cells
In what ways are the processes of mitosis and meiosis the different?
*Mitosis cells divide once, meiosis cells divide twice
*Mitosis creates 2 diploid cells that are identical, meiosis creates 4 different haploid cells
*mitosis is for cell growth, repair, and replacement, meiosis is for fertilization
*mitosis has strict organization tto create exact duplicates, meiosis has no organization
*mitosis’ metaphase has cells that line up in a single file, metaphase of mitosis I of meiosis has cells that line up in homogolous pairs
What is the chromosomal difference between gametes and zygotes?
gamete: a haploid and carries half the number of genetic material needed in a normal cell
zygote: diploid and carries all the genetic material needed in a normal cell
Be able to distinguish between a chromatid and a chromosome.
chromatid: replicated genetic material that’s found in prophase and metaphase
chromosome: original genetic material
Explain what homologous chromosomes are.
homologous chromosomes: the same chromosome from each parent
Be able to recognize a cell in prophase, metaphase, or anaphase of Mitosis. Be sure and indicate the “ploidy” (haploid, or diploid) of the cell at the beginning and end of mitosis.
prophase: haploid
metaphase: haploid
anaphase: diploid
Starting with a diploid organism (with 3 unique chromosomes: a long one, a medium one, and a short one, be able to sketch a cell in the following phases of meiosis: Prophase I, Metaphase I, Anaphase I, Telophase I, Metaphase II, Anaphase II, Telophase II). In which phases are the cells haploid? Diploid? In which phase does crossing over occur? In which phase does the random choice of which chromosome goes into which gamete (independent assortment) occur?
crossing over occurs in prophase I
independent assortment occurs in metaphase I
Diploid until it becomes haploid in telophase i
Be able to distinguish in a sketch prophase, metaphase and anaphase between mitosis,
Meiosis I and meiosis II.
Use sketches to help you describe the fate of the chromosomes of a diploid organism (with 3
unique chromosomes: a long one, a medium one, and a short one) during mitosis. Start with a cell in early interphase before replication. Then describe mitosis, including prophase, metaphase, anaphase, telophase and cytokinesis. Use the words kinetochore, spindle, metaphase plate, sister chromatids, daughter cells.
kinetichore: right by centromere and allows spindle to attach to chromosome’s centromere
spindle: attaches to centromeres using kinetichore in metaphase
metaphase plate: where chromosomes line up in metaphase
sister chromatids: replicated chromosomes found in prophase
Daughter cells: haploid and the final cells that are divided into two in cytokinesis
