Cell Divisions: Meiosis and Mitosis Lab Flashcards
What is a diploid?
a cell with 2 sets of homologous chromosomes (2n)
What is a haploid?
a cell with only 1 set of chromosomes (n)
What is the cell cycle?
G1 phase, S phase, G2 phase, and Mitotic (M) phase
How long does mitosis take in the cell cycle?
5 to 10% of the cell cycle
G1 Phase
organelle duplication, growth, and 8-10 hours
S Phase
DNA replicates, growth, and 6-8 hours
G2 Phase
prepares for mitosis, growth, and 4-6 hours
What four stages are in Mitosis?
prophase, metaphase anaphase, telophase (PMAT)
What are the end result of mitosis?
exact copies of parent cell
What happens during prophase?
nucleolus has disappeared and duplicated chromosomes are visible. Each chromatid is attached to a spindle fiber
What happens during metaphase?
centromeres of duplicated chromosomes are aligned at the equator. Spindle fibers attached to the sister chromatids come from opposite spindle poles
What happens during anaphase?
sister chromatids part and become daughter chromosomes that move toward the spindle poles
What happens during telophase?
daughter cells are forming as nuclear envelopes and nucleoli reappear. Chromosomes will become indistinct chromatin
What is cytokinesis?
the division of the cytoplasm
When does cytokinesis occur?
begins in anaphase, continues in telophase, and reaches completion by the start of the next interphase
What is meiosis?
a form of nuclear division that results in the gametes containing half the number of chromosomes found in the species
What occurs during prophase I?
the chromosomes are in a fragmented nuclear envelope, and the homologues undergo crossing-over
What results from meiosis?
results in the formation of 4 haploid daughter cells
What happens during crossing-over?
the non-sister chromatids of a homologue pair exchange genetic material
What occurs during Metaphase I?
the homologues are at the equator, prepared to move apart toward the poles. Each homologue pair acts independently, and either homologue can be facing either pole
What happens during anaphase I?
the members of each homologue pair separate, and they move toward opposite poles. Now the nuclei will be haploid: they no longer have homologue pairs
What happens during telophase I?
daughter cells have one homologue from each homologue pair
What is interkinesis?
the period between meiosis I and meiosis II
What is deletion?
the chromosome is shorter than usual because come portion is missing
What is duplication?
the chromosome is longer than usual because some portion is present twice over
What is inversion?
the chromosome is normal in length but some portion runs in the opposite direction
What is translocation?
two chromosomes have switched portions, and each switched portion is on the wrong chromosome
What is a syndrome?
characterized by a group of symptoms and conditions that always occur together
