Cell Organelles and Mitosis Quiz

Cell Organelles

Nucleus: Contains genetic material (DNA); controls cellular activities.
Mitochondria: Powerhouse of the cell; site of ATP production through respiration.
Ribosomes: Synthesize proteins; can be free in the cytoplasm or attached to the endoplasmic reticulum (ER).
Endoplasmic Reticulum (ER):
- Rough ER: Studded with ribosomes; involved in protein synthesis and processing.
- Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies toxins.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to organelles.
Lysosomes: Contain digestive enzymes; break down waste materials and cellular debris.
Chloroplasts: Found in plant cells; site of photosynthesis.
Cell Membrane: Semi-permeable barrier; regulates entry and exit of substances.

Mitosis and Meiosis

Mitosis:
- Purpose: Cell division for growth and repair; produces two identical daughter cells.
- Stages:
  1. Prophase: Chromatin condenses into chromosomes; nuclear envelope breaks down.
  2. Metaphase: Chromosomes align at the cell's equatorial plane.
  3. Anaphase: Sister chromatids are pulled apart to opposite poles.
  4. Telophase: Nuclear envelope reforms; chromosomes de-condense.
Meiosis:
- Purpose: Produces gametes (sperms and eggs) for sexual reproduction.
- Stages:
  1. Meiosis I: Homologous chromosomes separate; reduces chromosome number by half.
  2. Meiosis II: Similar to mitosis; sister chromatids separate.
- Results in four genetically diverse daughter cells with half the original chromosome number.

Photosynthesis

Definition: Process by which green plants, algae, and some bacteria convert light energy into chemical energy.
Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂.
Key Components:
- Chlorophyll: Green pigment in chloroplasts; captures light energy.
- Light Reactions: Occur in thylakoid membranes; produce ATP and NADPH.
- Calvin Cycle: Occurs in the stroma; uses ATP and NADPH to convert CO₂ into glucose.

Cellular Respiration

Definition: Process by which cells convert glucose and oxygen into energy (ATP).
Equation: C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + ATP.
Stages:
1. Glycolysis: Occurs in the cytoplasm; breaks down glucose into pyruvate, yielding 2 ATP.
2. Krebs Cycle: Occurs in mitochondria; processes pyruvate, producing NADH and FADH₂.
3. Electron Transport Chain: Occurs in mitochondrial inner membrane; produces up to 34 ATP using electrons from NADH and FADH₂.

Tissue Types

Epithelial Tissue: Covers body surfaces, lines cavities, and forms glands; classified by shape (squamous, cuboidal, columnar) and layers (simple, stratified).
Connective Tissue: Supports and binds other tissues; includes bone, adipose, blood, and cartilage.
Muscle Tissue:
- Skeletal Muscle: Voluntary movements; striated and multinucleated.
- Cardiac Muscle: Involuntary movements; striated and branched; found in heart.
- Smooth Muscle: Involuntary movements; non-striated; found in walls of hollow organs.
Nervous Tissue: Composed of neurons and glial cells; responsible for transmitting impulses and processing information.

Biodiversity

Definition: Variety of life on Earth; includes the diversity of species, ecosystems, and genetic variation.
Levels of Biodiversity:
1. Species Diversity: Variety of species within a habitat.
2. Genetic Diversity: Variation in genes among individuals within a species.
3. Ecosystem Diversity: Variety of ecosystems in a given area.
Importance:
- Ecosystem resilience: Biodiversity contributes to ecosystem stability and recovery.
- Economic value: Biodiversity supports agriculture, medicine, and tourism.
- Cultural significance: Biodiversity is integral to cultural identities and practices.
Threats: Habitat loss, pollution, climate change, overexploitation, and invasive species.

Cell Organelles

Nucleus: Houses DNA and regulates cellular operations including growth and reproduction.
Mitochondria: Known as the powerhouse; responsible for ATP synthesis via cellular respiration.
Ribosomes: Sites for protein synthesis, found freely in the cytoplasm or attached to the endoplasmic reticulum.
Endoplasmic Reticulum (ER):
- Rough ER: Contains ribosomes; facilitates protein synthesis and post-translational modifications.
- Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies harmful substances.
Golgi Apparatus: Processes, modifies, and sorts proteins and lipids for secretion or transport to other cell parts.
Lysosomes: Enzyme-filled organelles that digest waste and recycle cellular material.
Chloroplasts: Present in plants; central to photosynthesis, converting light energy into glucose.
Cell Membrane: Semi-permeable structure that regulates the transport of substances into and out of the cell.

Mitosis and Meiosis

Mitosis: Cell division mechanism for growth and repair, yielding two genetically identical daughter cells.
Stages of Mitosis:
- Prophase: Chromatin condenses to form visible chromosomes, and the nuclear envelope dissolves.
- Metaphase: Chromosomes align along the cell's equator.
- Anaphase: Sister chromatids are separated and pulled to opposite sides.
- Telophase: Chromosomes unwind back to chromatin, and nuclear envelopes reform.
Meiosis: Special type of division producing gametes for sexual reproduction, resulting in genetic diversity.
Stages of Meiosis:
- Meiosis I: Homologous chromosomes segregate, halving the chromosome number.
- Meiosis II: Similar to mitosis, separating sister chromatids.
Ends with four diverse daughter cells each having half the parent chromosome count.

Photosynthesis

Definition: Process where autotrophs convert light energy into chemical energy.
Photosynthesis Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂.
Key Components:
- Chlorophyll: Green pigment responsible for absorbing light, primarily in chloroplasts.
- Light Reactions: Take place in thylakoid membranes, generating ATP and NADPH.
- Calvin Cycle: Involves conversion of CO₂ into glucose using energy carriers ATP and NADPH.

Cellular Respiration

Definition: Biochemical process converting glucose and oxygen into ATP energy.
Cellular Respiration Equation: C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + ATP.
Stages:
- Glycolysis: Occurs in the cytoplasm; breaks down glucose into pyruvate, yielding 2 ATP.
- Krebs Cycle: Takes place in mitochondria; processes pyruvate to produce NADH and FADH₂.
- Electron Transport Chain: Located in the mitochondrial inner membrane; generates up to 34 ATP using input from NADH and FADH₂.

Tissue Types

Epithelial Tissue: Covers and protects body surfaces and cavities; categorized by shape—squamous, cuboidal, columnar—and arrangement—simple or stratified.
Connective Tissue: Supports and binds all parts of the body; includes bone, adipose, blood, and cartilage.
Muscle Tissue:
- Skeletal Muscle: Striated, voluntary; responsible for movement.
- Cardiac Muscle: Involuntary, striated, and branched; found only in the heart.
- Smooth Muscle: Non-striated and involuntary; located in walls of internal organs.
Nervous Tissue: Composed of neurons and support cells; essential for transmitting signals and processing information.

Biodiversity

Definition: The variety of life forms on Earth, encompassing species, ecosystems, and genetic diversity.
Levels of Biodiversity:
- Species Diversity: Different types of species within a habitat.
- Genetic Diversity: Variability of genes within a species.
- Ecosystem Diversity: Range of different ecosystems in a region.
Importance of Biodiversity:
- Enhances ecosystem resilience and stability.
- Supports agriculture, medicine, and tourism through natural resources.
- Integral to cultural identities and practices.
Threats to Biodiversity: Including habitat destruction, pollution, climate change, overexploitation, and the introduction of invasive species.