Biology: Cells, Osmosis, and Stem Cells

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the key difference between prokaryotes and eukaryotes?

Prokaryotes have a nucleus, while eukaryotes do not.

Eukaryotes are always bacteria, while prokaryotes are not.

Prokaryotes are always multicellular, while eukaryotes are single-celled.

Eukaryotes have membrane-bound organelles, while prokaryotes do not. (correct)

Which solution causes a cell to swell due to water moving into it?

Hypotonic solution (correct)

Neutral solution

Hypertonic solution

Isotonic solution

What defines a malignant tumor?

A tumor that only grows in response to external stimuli.

A tumor that appears harmless and is easy to remove surgically.

A tumor that stays in one area and does not spread.

A cluster of cells that interfere with normal functions and may destroy surrounding tissues. (correct)

Which method is used to specifically target cancer cells using lasers?

Biophotonics Signup and view all the answers

What is one critical factor in the detection of abnormal moles?

Evolving characteristics Signup and view all the answers

Which type of stem cells can differentiate into any cell type?

Embryonic stem cells Signup and view all the answers

What is a common cause of cancer that relates to heredity?

Inherited genetic mutations Signup and view all the answers

In the context of osmosis, what does a semipermeable membrane allow?

Only water to pass through Signup and view all the answers

What is the primary function of capillaries in the circulatory system?

Transport nutrients and waste between blood and tissues Signup and view all the answers

Which condition is NOT associated with the respiratory system?

Osteoporosis Signup and view all the answers

What is the main greenhouse gas that has increased significantly due to human activities?

Carbon dioxide Signup and view all the answers

What is a major effect of rising CO2 levels on the environment?

Decreased plant growth Signup and view all the answers

Which structure is responsible for bringing deoxygenated blood from the lower body to the heart?

Inferior vena cava Signup and view all the answers

What phenomenon explains the trapping of heat in Earth's atmosphere?

The greenhouse effect Signup and view all the answers

Which of the following is a consequence of global warming on weather patterns?

Inconsistent rain and prolonged dry periods Signup and view all the answers

Which neurological condition involves the immune system attacking the protective covering of nerves?

Multiple Sclerosis Signup and view all the answers

What is the primary impact of climate change on agriculture in regions like Afar, Ethiopia?

Inconsistent rainfall affecting crop yields Signup and view all the answers

Which artery is the largest and carries oxygenated blood from the heart to the body?

Aorta Signup and view all the answers

Which organelle is present in plant cells but not in animal cells?

Chloroplasts Signup and view all the answers

In which phase of mitosis do chromosomes align in the middle of the cell?

Metaphase Signup and view all the answers

What is the primary function of amylase in the digestive system?

Breaking down carbohydrates Signup and view all the answers

What type of digestion is characterized by the physical breakdown of food?

Mechanical digestion Signup and view all the answers

Which blood component is primarily responsible for oxygen transport?

Red blood cells Signup and view all the answers

Which part of the respiratory system is directly involved in the exchange of gases?

Alveoli Signup and view all the answers

What is the role of myelin in the nervous system?

Insulate neurons Signup and view all the answers

What type of tissue primarily connects muscles to bones?

Tendons Signup and view all the answers

Which structure helps regulate involuntary functions in the body?

Peripheral nervous system Signup and view all the answers

What is the main purpose of the circulatory system?

To deliver oxygen and nutrients Signup and view all the answers

Which part of the digestive system is responsible for nutrient absorption?

Small intestine Signup and view all the answers

How do alveoli facilitate efficient gas exchange?

By being surrounded by blood vessels Signup and view all the answers

What occurs during telophase of mitosis?

Nuclear envelope forms around chromosomes Signup and view all the answers

Study Notes

Prokaryotes and Eukaryotes

Prokaryotes are single-celled organisms (like bacteria) without a nucleus or membrane-bound organelles.
Eukaryotes are organisms with cells containing a nucleus and membrane-bound organelles (like plants, animals, and fungi).

Osmosis and Diffusion

Diffusion: Particles move from high concentration to low concentration.
Osmosis: Water moves across a membrane.
Cell membranes are semipermeable (some things can pass).
Hypertonic: Solution with more solutes outside the cell than inside; water moves out, cell shrinks.
Hypotonic: Solution with fewer solutes outside the cell than inside; water moves in, cell swells (or bursts).
Isotonic: Solution with the same solute concentration inside and outside the cell; water moves in and out equally, cell size stays the same.

Stem Cells

Stem cells are unspecialized cells that divide and differentiate into specialized cell types.
Types include embryonic (can become any cell type) and adult (limited to specific cells).
Importance: Used to study diseases, develop treatments, and regenerate damaged tissues (e.g., cancer treatment).

Cancer

Cancer occurs when cells grow and divide uncontrollably due to mutations.
Causes include inherited factors, aging, and harmful substances (e.g., smoking, UV light).
Cancer cell traits: Uncontrolled growth, immune system avoidance, spreading, and tissue damage.
Types of Tumors:
- Metastatic: Spread to other areas.
- Benign: Stay in one area.
- Malignant: Mass of cells interfering with normal functions of neighboring cells; may destroy surrounding tissues.

Detecting and Screening Cancer

Methods include medical imaging (MRI and CT scans).
ABCDE rule for detecting skin cancer:
- Asymmetry: One half doesn't match the other.
- Border: Irregular, blurred, or notched edges.
- Color: Uneven colors (black, brown, red, white, blue).
- Diameter: Larger than 6mm (pencil eraser size).
- Evolving: Changes in size, shape, or color.

Treatments for Cancer

Surgery: Removing tumors (drawback: large/inaccessible tumors).
Chemotherapy: Drugs that kill fast-growing cells (drawback: tissue damage).
Radiation: Damages cancer cell DNA.
Biophotonics: Uses lasers to target cells.

Animal and Plant Cell Differences

Similarities: Both have a cell membrane, cytoplasm, nucleus, mitochondria, and ribosomes. Both undergo mitosis, and cellular respiration
Animal Cells: No cell wall, no chloroplasts, small or no vacuole, round shape.
Plant Cells: Cell wall for support and structure, chloroplasts for photosynthesis, large central vacuole, rectangular shape.

Mitosis Stages

Interphase: DNA replicates; cell lives its life cycle
Prophase: Chromosomes condense, nuclear envelope breaks down, spindle fibers form.
Metaphase: Chromosomes align in the cell's middle, spindle fibers attach.
Anaphase: Sister chromatids separate and move to opposite poles.
Telophase: Chromosomes unravel, new nuclear membranes form around each set.
Cytokinesis: Cytoplasm divides; animal cells pinch, plant cells form a cell plate.

Enzymes and Digestive System

Amylase: Found in saliva; breaks down carbohydrates.
Pepsin: Found in stomach; breaks down proteins.
Trypsin: Found in small intestine; continues protein breakdown.
Lipase: Found in small intestine; breaks down fats/lipids.

Digestion Process

Chemical Digestion: Enzymes break down food.
Mechanical Digestion: Physical breakdown of food (e.g., teeth, stomach churning).

Human Organ Systems

Digestive System:*
- Mouth (chewing, amylase), Esophagus (transport), Stomach (mechanical and chemical digestion), Small Intestine (nutrient absorption), Large Intestine (water absorption, waste).
- Accessory organs (liver and gallbladder) support digestion without touching food.
Circulatory System:*
- Functions: Delivers oxygen and nutrients, removes wastes, transports hormones, regulates temperature.
- Essential parts: Heart (pump), blood (fluid), blood vessels (arteries, veins, capillaries).
- Blood components: Plasma (water, dissolved substances), Red Blood Cells (oxygen transport), White Blood Cells (immunity), Platelets (clotting).
Respiratory System:*
- Path of air: Nose/Mouth (entry), Trachea (airway), Bronchi (branches), Bronchioles (smaller branches), Alveoli (gas exchange), Diaphragm (breathing muscle).
Musculoskeletal System:*
- Bones: Support, protection, mineral storage, blood cell production.
- Ligaments: Connect bones at joints, provide stability.
- Cartilage: Smooth surface at joints, reduces friction.
- Tendons: Connect muscles to bones, enable movement.
- Muscles: Contract to move bones, work in pairs.
Nervous System:*
- Central Nervous System (CNS): Brain, spinal cord; processes information, coordinates responses.
- Peripheral Nervous System (PNS): Nerves connecting CNS to body control muscles, carries sensory info, regulates involuntary actions.
- Neurons: Transmit electrical signals, some have myelin for faster signal transmission.
- Sensory Receptors: Detect light, temperature, chemicals, pressure, pain.
- Spinal Cord: Relay station for reflexes and communication brain-body.

Short Answer - Multiple Organ Systems

Lungs (respiratory): Alveoli increase surface area for gas exchange.
Small Intestine (digestive): Villi and microvilli increase nutrient absorption surface area.
Capillaries (circulatory): Extensive network maximizes gas, nutrient, and waste exchange with tissues.
Skin (integumentary): Large surface area for temperature regulation and environmental sensing.
Brain (nervous): Folds (gyri and sulci) increase surface area for neuronal processing/control.

Systems Working Together

Respiratory and Circulatory Systems: Work in tandem to transport oxygen to cells, and remove carbon dioxide.
Musculoskeletal and Nervous Systems: Coordinate movement and body functions.
Digestive and Circulatory Systems: Break down food and transport nutrients.

Gas Exchange in Lungs

Alveoli in lungs facilitate diffusion of oxygen into blood and carbon dioxide out of blood.

Respiratory System Issues

Tuberculosis (TB): Infectious Lung disease
Lung Cancer: Often caused by smoking and is preventable.
Vaping: Harms lungs, long-term effects still being studied.
COVID-19: Virus impacting breathing.

Nervous System Issues

Concussion: Brain injury.
Multiple Sclerosis: Immune system damages myelin.
Paralysis: Severe spinal cord damage.

Heart and Blood Flow

Blood movement: Pulmonary (lungs) and Systemic (body) loops.
Path summary: Oxygenated blood leaves heart via arteries, deoxygenated returns via veins. Capillaries facilitate gas and nutrient transfer.
Key Blood Vessels: Superior/Inferior Vena Cava, Pulmonary Veins and arteries, Aorta

Climate Change

Greenhouse gases: Trap heat in atmosphere, leading to warming, causing problems with global warming. (e.g. Carbon dioxide, Methane)
Climate change: Long-term changes in weather patterns (e.g., temperature, rainfall, storms).
Global warming: Overall increase in Earth's average temperature.
Climate vs. Weather: Climate is long-term weather averages, weather is day-to-day conditions.
Evidence of global warming: Increasing CO2 levels, melting glaciers, rising sea levels, and more extreme weather.

Carbon Dioxide (CO2)

A greenhouse gas, naturally occurring but increased by human activities.
CO2 levels have risen dramatically since the Industrial Revolution, due to activities like burning fossil fuels and deforestation.
Present levels are the highest in over 800,000 years. Increased CO2 means more trapped heat, which has significant impact on the planet:

Climate Change Effects

Examples of effects, including reduced agricultural productivity due to irregular and less rainfall, increased drought risk for agriculture and animals, and increase in heat waves, causing health problems.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers essential concepts in biology regarding prokaryotic and eukaryotic cells, as well as the processes of osmosis and diffusion. Additionally, it explores the fundamental characteristics of stem cells and their types. Test your knowledge on these critical biological principles!