IBDP Biology Exam Study Guide

Topic 1: Cells

Topic 1.1: Introduction to Cells

1. State the 3 principles of the cell theory.

a. All living things are made of cells/cell products, the cell is the smallest unit of life, cells arise from existing cells

2. What are examples of “exceptions” to the cell theory? Explain why these are considered exceptions.

a. Striated cells – more than one nucleus per cell, muscle cells called fibers can be long, surrounded by a single plasma membrane

b. Giant algae – giganticin size (5-100mm), challenges the idea that cells must be simple in structure and small in size

c. Aseptate fungal hypae – challenges the idea that the cell is a single unit, - very large w many nuclei

3. State the functions of life.

a. Metabolism, response, homeostasis, excretion, nutrition, growth, reproduction

4. Why is surface area to volume ratio important in the limitation of cell size?

a. Bc smaller cells are more efficient than big cells – the rate of metabolism of a cell id a function of it’s mass/volume

5. Determine the magnification and actual size of electron micrographs.

a. Magnification – measure scale bar, convert to appropriate unit, calculate magnification by division of converted scale bar over scale bar value

b. Actual size – measure object/image, convert to appropriate unit, calculate actual size by image s/w unit over magnification

6. How do cells specialize?

a. Newly formed cells specialize by deactivating genes

7. What are types of stem cells? Give an example of each.

a. Totipotent – differentiate into any type of cell (stem cell)

b. Pluripotent – differentiate into many types of cell (umbilical cord stem cell)

c. Multipotent – differentiate into few closely related type of cell (bone marrow)

d. Unipotent – can regenerate but only their cell type (liver cell)

8. What are current uses of stem cells in research and medicine?

Topic 1.2: Ultrastructure of Cells

9. Compare and contrast prokaryotic cells and eukaryotic cells.

a. Pro-

i. Dna located in cytoplasm/not nucleus

ii. Dna is 1 circular chromosome

iii. No membrane bound organelles

iv. Usually smaller than eukaryotes

v. Divides by binary fission

vi. Can have plasmids

b. Eu-

i. Dna is associated with ptoeins

ii. Dna found in nucleus

iii. Has membrane bound organelles

iv. Divides by meiosis/ mitosis

v. Have centrioles

vi. No plasmids

10. Analyze electron micrographs to identify various organelles.

a. check

11. Draw and label a prokaryotic cell.

a. check

Topic 1.3: Membrane Structure

12. Draw and label the structure of the cell membrane.

a. check

13. List and describe three types of proteins associated with the cell membrane.

a. Integral – permanently embedded in the cell membrane

b. Peripheral – have a temporary association with the cell membrame

c. Glycoprotein – protein w a sugar/carbohydrate chain attached to the top of it

Topic 1.4: Membrane Transport

14. Define the terms: diffusion, facilitated diffusion, osmosis and active transport.

a. Diffusion – positive net movement of particles from an area of high to low concentration

b. Omosis – diffusion of water across the membrane; passive

c. Facilitated diffusion – high to low diffusion using a transport protein

d. Active transport – net movement using energy

15. Estimate osmolarity in tissues. (Think about potato lab.)