Biology 1001A Lecture Notes - Lecture 2: Intermediate Filament, Spindle Checkpoint, Chromatin
Document Summary
Prelecture: phases and main characteristics of the cell cycle. Interphase:- g1 phase: cell carries out its function and growth. G0 phase: cells that are not destined to divide immediately enter a shunt from g1; re-enter g1 in order to start dividing again. S phase: dna replication and chromosomes duplicate. G2 phase: cell growth continues and prepares for mitosis; cohesins appear encircle each pair of sister. Cytokinesis: cytoplasm divides by furrowing (animal cells) or by forming a cell plate (plant cells: stages and main characteristics of mitosis, prophase. Chromosomes condense, this condensation packs the long dna molecules into small units. Nucleolus becomes smaller and disappears = shut down of all types of rna synthesis. In the cytoplasm, mitotic spindle begins to form between the two centrosomes, pushing the centrosomes to opposite ends, thereby forming the spindle poles. The spindle develops as bundles of microtubules: prometaphase. Spindle microtubules grow from centrosome toward the former nuclear area and attach to the chromosomes.