Mitosis Flashcards

Mitosis Overview

• Mitosis is the process of nuclear division in eukaryotic cells, resulting in two genetically identical daughter cells.
• Cytokinesis follows mitosis, where the cytoplasm divides between the new daughter cells.

Key Terms in Mitosis

• A chromatid is one of the two identical halves of a chromosome.
• The centromere is a chromosome region where sister chromatids are connected, serving as the attachment point for spindle fibers during division.

Cell Cycle

• The cell cycle comprises interphase, mitosis, and cytokinesis, facilitating cell growth and development.
• Interphase is a preparatory phase where cells grow and perform regular functions, lasting longer than division phases.

Phases of Mitosis

• Prophase is the first and longest phase, characterized by visible chromosomes, movement of centrioles to poles, and the disappearance of the nuclear membrane.
• In metaphase, chromosomes align in the middle of the cell.
• Anaphase sees chromatid arms separate and migrate to opposite ends of the cell.
• Telophase is the final phase where two nuclei form, chromosomes revert to chromatin, and the nuclear membrane begins to reappear.

Chromosomes and Genetic Material

• Homologous chromosomes are pairs of similar chromosomes carrying genes for the same traits.
• Chromosomes are compacted DNA seen during cell division, while chromatin is the loose form of DNA during non-dividing phases.

Prokaryotic vs. Eukaryotic Cell Division

• Binary fission is a prokaryotic cell division method resulting in two identical daughter cells, prevalent in bacteria.
• Prokaryotes lack a nucleus or membrane-bound organelles, while eukaryotes possess both.

Regulatory Proteins

• Internal regulators are proteins that ensure specific cellular processes must occur before the cell cycle continues.
• External regulators are proteins that respond to external signals, influencing the speed of the cell cycle.

Cancer and Cell Growth

• Carcinogens are substances that can damage DNA and contribute to cancer development.
• Cancer arises from cells that lose control over their growth, leading to uncontrolled proliferation.

Cellular Structures in Division

• Centrioles are cylindrical structures that aid in chromosome separation during division by organizing spindle fibers.
• The spindle is a fan-like microtubule structure crucial for separating chromosomes during mitosis.
• The centrosome is the central region housing centrioles, playing a key role in organizing spindle fibers.

Types of Cells

• Somatic cells refer to all body cells except for sperm and egg cells, forming the majority of an organism's structure.