Biology Mitosis Concepts

Mitosis and Cell Division

• Mitosis is the process of dividing genetic material in eukaryotic cells.
• Sister chromatids separate during anaphase, moving to opposite poles, each now considered a chromosome.
• Prophase involves chromosome condensation, separation of centrosomes, and potential nuclear envelope fragmentation.
• Telophase marks the arrival of chromosomes at poles, forming new nuclear membranes and preparing for cytokinesis.

Chromosomal Structures

• Acrocentric chromosomes have one significantly longer arm.
• Metacentric chromosomes have arms of similar lengths.
• The centromere is the DNA region connecting sister chromatids.
• Aster structures form around centrosomes during mitosis, with astral rays radiating from the centrosphere.

Cytokinesis

• In animal cells, cytokinesis involves a cleavage furrow formed by a contractile ring of actin and myosin.
• Plant cells form a cell plate during cytokinesis, derived from cell wall materials transported to the division site.

Genetic Material and Packaging

• Chromatin is a complex of DNA, RNA, and proteins that condenses DNA for cell division.
• Nucleosomes are the basic units of DNA packaging, consisting of DNA wrapped around histone proteins.
• The telomere protects chromosome ends from deterioration, consisting of repetitive nucleotide sequences.

Cell Cycle and Phases

• Interphase includes G1, S (DNA replication), and G2 phases.
• Cyclins accumulate at the G1/S checkpoint, signaling the onset of mitosis.
• Density-dependent inhibition refers to the growth of a population being regulated by its density.

Types of Cell Division

• Meiosis includes two rounds of division: Meiosis I separates homologous chromosomes, while Meiosis II separates sister chromatids.
• Crossing over occurs during prophase I of meiosis, exchanging genetic material between homologous chromosomes at chiasmata.

Genetic Variation and Cancer

• Oncogenes have the potential to contribute to cancer, while proto-oncogenes are normal genes that may mutate.
• Tumor suppressor genes regulate cell growth and prevent tumor formation.

Transport Mechanisms

• Diffusion is the passive movement of molecules from higher to lower concentration areas.
• Active transport moves molecules against their concentration gradient, requiring energy.
• Exocytosis and endocytosis are processes for moving substances into and out of cells.

Specialized Cellular Functions

• Spermatogenesis involves producing sperm cells through meiotic divisions.
• Oogenesis refers to the formation of ova (egg cells).
• Follicles are structures within the ovaries that support oocyte development.

Miscellaneous Terms

• Karyotype is the map of chromosomes in a cell.
• Kinetochore fibers attach spindle apparatus to chromosomes, crucial for proper chromosome segregation.
• Chiasma represents contact points between non-sister chromatids during crossing over.

Test your understanding of key mitosis terms with this set of flashcards. Each card features a word related to cellular division and its definition, designed to reinforce your biology knowledge. Perfect for students looking to excel in their biology classes.