Cell Division and Reproduction Asexual Reproduction Only 1 parent required for asexual reproduction. Fast and simple process. Results in identical offspring without genetic variation. Examples include binary fission in bacteria. Sexual Reproduction Involves 2 parents contributing to offspring. Offspring genetically different from parents. Slower and more expensive compared to asexual reproduction. Leads to genetic variation, aiding evolution in changing environments. Modes of Reproduction Asexual reproduction involves a single parent producing genetically identical offspring through binary fission. Example: Amoeba divides by binary fission to form daughter cells. Sexual reproduction requires two parents contributing to genetically diverse offspring. Genetic variation in sexual reproduction allows adaptation to environmental changes. Eukaryotic Cell Division Mitosis produces identical daughter cells for asexual reproduction, growth, and repair. Meiosis generates different daughter cells for sexual reproduction and gamete formation. Meiosis results in four unique daughter cells compared to two identical cells in mitosis. Cell Cycle and Mitosis Eukaryotic Cell Division Mitosis results in daughter cells identical to the parent cell. Occurs in asexual reproduction, growth, development, and repair. Meiosis produces daughter cells different from parents for sexual reproduction. Involves the formation of gametes like sperm and egg. Eukaryotic Chromosomes Chromosomes are tightly coiled DNA structures. Human cells (except gametes) typically have 46 chromosomes. Genes are specific DNA sequences on chromosomes. Chromatin, a looser DNA form, condenses into chromosomes before cell division. The Cell Cycle Ordered sequence of events from cell formation to division. Consists of interphase (cell growth and DNA replication) and mitotic phase (DNA and cytoplasmic division). Interphase includes G1 (cell growth), S (DNA duplication), and G2 (preparation for division). Stages of Mitosis Prophase: Chromosomes coil tightly, spindles form. Prometaphase: Nuclear envelope breaks, microtubules attach to chromatids. Metaphase: Chromosomes align at the cell's equator. Anaphase: Sister chromatids separate and move to opposite ends. Telophase: Chromosomes decondense, nuclear envelope reforms. Cytokinesis: Cytoplasm divides, forming two daughter cells. Mitosis and Cell Division Mitotic Spindle Microtubules that separate chromosomes during mitosis. Aids in pulling DNA to opposite ends of the cell. Essential for proper chromosome distribution. Ensures accurate division of genetic material. Mitosis Summary Results in two daughter cells identical to the parent cell. Utilized in asexual reproduction, growth, and repair. Mathematically, chromosome count doubles during S phase and halves after cytokinesis. Ensures genetic stability and continuity in cell populations. Comparing Binary Fission and Mitosis Both processes involve chromosome duplication and cell division. Mechanics and timing differ between bacterial binary fission and eukaryotic mitosis. DNA replication and separation occur simultaneously in binary fission, unlike in mitosis. Mitotic spindle formation is unique to eukaryotic cell division. Cancer and Cell Cycle Cell cycle checkpoints regulate cell division. Disruption of checkpoints, like the G1/S checkpoint, can lead to cancer. Tumors result from uncontrolled cell growth. Benign tumors stay localized, while malignant tumors can metastasize. Eukaryotic Chromosomes and Cell Cycle Chromatin and Chromosomes Chromatin organizes DNA into chromosomes before cell division. Gene: a sequence of nucleotides on a chromosome. Sister chromatids are duplicated chromosomes held by a centromere. The Cell Cycle Phases Interphase: cell growth and DNA replication stages. Mitotic Phase: includes mitosis and cytokinesis for cell division. Mitosis stages: Prophase, Prometaphase, Metaphase, Anaphase, Telophase.

Asexual Reproduction

Reproduction with only 1 parent, fast and simple, producing identical offspring

Sexual Reproduction

Reproduction with 2 parents, slower and more expensive, producing genetically different offspring

Binary Fission

A form of asexual reproduction in prokaryotes involving duplication and division of the cell

Mitosis

Eukaryotic cell division resulting in daughter cells identical to the parent, crucial for asexual reproduction, growth, and repair

Meiosis

Eukaryotic cell division resulting in daughter cells different from the parent, essential for sexual reproduction and gamete formation

Chromosome

Tightly coiled piece of DNA, with the number varying between species

Gene

Distinct sequence of nucleotides on a chromosome

Chromatin

Loose form of DNA when not tightly coiled into chromosomes, coils up before cell division

Sister Chromatids

Identical copies of a chromosome attached at the centromere

Cell Cycle

Ordered sequence of events from cell formation to division, consisting of interphase and mitotic phase

Interphase

Cell growth and DNA replication phase of the cell cycle

Cytokinesis

Division of the cytoplasm following mitosis, resulting in two separate daughter cells

Mitotic Spindle

Microtubules that separate chromosomes during mitosis

Prophase

First stage of mitosis where chromosomes coil tightly and spindles form

Prometaphase

Stage of mitosis where the nuclear envelope breaks down and microtubules attach to centromeres

Metaphase

Stage of mitosis where duplicated chromosomes line up in the middle of the cell

Anaphase

Stage of mitosis where sister chromatids separate and move to opposite ends of the cell

Telophase

Final stage of mitosis where chromosomes decondense, spindle fibers disappear, and nuclear envelope reforms

Tumor

Abnormal mass of cells resulting from uncontrolled cell division, can be benign or malignant

Checkpoint

Regulatory point in the cell cycle determining if a cell is ready to proceed, with the G1/S checkpoint being crucial

Benign Tumor

Non-cancerous tumor that remains at the original site

Malignant Tumor

Cancerous tumor capable of spreading to other locations through metastasis

Metastasis

Process of cancer cells spreading to other parts of the body

Cancer

Condition where an individual has a malignant tumor

Anticancer Agents

Treatments targeting rapidly growing cells like cancer cells

Radiation Therapy

Uses high-energy radiation to damage cancer cells more than normal cells

Chemotherapy

Treatment for metastatic cancers, disrupts cell division

Cell Division

Process of cells reproducing, growing, and repairing

Gametes

Reproductive cells like sperm and egg

Genetic Variation

Differences in genetic makeup providing potential for evolution