Presentation with summary of IB Biology topic 'Introduction to Cells' for the 2016 syllabus

1. INTRODUCTION TO CELLS
IB BIOLOGY –2016 SYLLABUS
www.ibscrewed.org

2. CELL THEORY
•ACCORDING TO CELL THEORY, ALL LIVING THINGS ARE COMPOSED OF CELLS
•HUMANS, E. COLI, SPIDERS, ALGAE –ALL OF THEM HAVE CELLS
•CELLS ARE CONSIDERED THE BASIC BUILDING BLOCKS OF LIFE

3. UNICELLULAR ORGANISMS
•ORGANISMS CONSISTING OF ONLY ONE CELL CAN CARRY OUT ALL THE FUNCTIONS OF LIFE
•THESE INCLUDE BACTERIA AND PROKARYOTIC CELLS
•THE MAIN FUNCTIONS OF LIFE INCLUDE: METABOLISM, RESPONSE TO CHANGING ENVIRONMENTS, HOMEOSTASIS, GROWTH, REPRODUCTION AND NUTRITION

4. SURFACE AREA TO VOLUME RATIO
•CELLS MOVE THEIR NUTRIENTS, PROTEINS AND OTHER MOLECULES THROUGHTHEIR CYTOPLASM USING DIFFUSION
•AS CELLS GET LARGER, IT TAKES LONGER FOR NEEDED MOLECULES TO DIFFUSE
•THE RATIO CREATES A LIMIT ON THE POTENTIAL SIZE OF CELLS
푹풂풕풊풐= 푺풖풓풇풂풄풆푨풓풆풂 푽풐풍풖풎풆

5. EMERGENT PROPERTIES
• ON THEIR OWN, INDIVIDUAL CELLS CAN PERFORM CERTAIN FUNCTIONS
• HOWEVER, WHEN THEY WORK TOGETHER IN A MULTICELLULAR
ORGANISMS, THE TEAMWORK LEADS TO NEW PROPERTIES
• THEY ARE CALLED ‘EMERGENT PROPERTIES’
• FOR EXAMPLE, CELLS IN THE HEART WORK TOGETHER TO CREATE A
PUMP: A SINGLE CELL COULD NOT PUMP BLOOD ON ITS OWN

6. SPECIALISATION
•ALL THE CELLS IN AN ORGANISM HAVE THE COMPLETE GENOME (GENETIC SEQUENCE)
•HOWEVER, WHEN CELLS DIFFERENTIATE(SPECIALISE), THEY ONLY EXPRESS SOME OF THE GENES, AND MAY TURN OFF OTHERS
•THE DIFFERENT EXPRESS CAUSES THE VARIOUS TYPES OF CELLS
•THE CELLS CAN THEN FORM SPECIALISED TISSUES LIKE SKIN, THE STOMACH, BRAIN OR LIVER

7. STEM CELLS
•STEM CELLS ARE UNDIFFERENTIATED CELLS
•THEY ARE CAPABLE OF BECOMING ANY TYPE OF CELL
•MAINLY FOUND IN EMBRYOS: THESE CELLS CAN BECOME ABSOLUTELY ANY TYPE OF CELL
•ADULT STEM CELLS ARE MORE LIMITED AND CAN ONLY BECOME SELECT CELL TYPES

8. THERAPEUTIC STEM CELLS
•STEM CELLS CAN BE USED FOR TISSUE REPAIR AND ORGAN REPLACEMENT
•THEY HAVE THE POTENTIAL TO CURE DISEASES AND REPAIR INJURIES (I.E. SPINAL INJURY, CYSTIC FIBROSIS)
•HOWEVER, THERE IS CONTROVERSY, SINCE THE BEST STEM CELLS ARE HARVESTED FROM EMBRYOS
•THERE HAS BEEN CULTURAL AND RELIGIOUS OBJECTIONS TO STEM CELL RESEARCH

9. STEM CELL RESEARCH
• SCIENTISTS FROM ACROSS THE GLOBE HAVE WORKED TOGETHER ON STEM
CELL RESEARCH, WHICH MAKES THE RESEARCH GO FASTER
• THE WORK HOLDS GREAT PROMISE FOR THE TREATMENT OF DIABETES, HEART
DISEASE, AND MANY MORE
• BONE MARROW STEM CELLS ARE ALREADY USED FOR THERAPY