Named Cell Types, Molecules, Scientists, Processes and Skills

ALL questions and answers for paper two. Exact IB mark scheme. Sorted by topic. 3-9 marks.

An example of the document: Topic 1: Cell Biology Describe the characteristics of stem cells that make them potentially useful in medicine. [5] (stem cells) have/retain the capacity to divide; can be used to produce cell cultures/large number of identical cells; can be used to repair/replace damaged/lost cells/tissue; (stem cells) are undifferentiated / have not yet differentiated/specialized; can differentiate/specialize in different ways / are pluripotent/totipotent; can be used to form a variety of different tissues / form organs; used in medical research; used in treatment of (named) disease; Draw a labelled diagram to show the structure of membranes. [5] phospholipid bilayer – with head and tails; hydrophilic/phosphate/polar heads and hydrophobic/hydrocarbon/fatty acid/ non-polar tails labelled; integral protein – embedded in hydrophobic region of the phospholipid bilayer; channel protein – integral protein showing clear channel/pore; peripheral protein – on the surface (not embedded in hydrophobic region) can be attached to integral protein; glycoprotein – with carbohydrate attached on outside; cholesterol – shown embedded in bilayer; Explain the importance of surface area to volume ratio as a factor limiting cell size. [7] as volume of a cell increases, the ratio of its surface area to volume decreases; food/oxygen enters through the surface of cells; wastes leave through the surface of cells; the rate of substance crossing the membrane depends on surface area; more metabolic activity in a larger cell means more food and oxygen required; large volume means longer diffusion time; (large volume) means more wastes produced; excess heat generated will not be lost efficiently (with low surface area to volume ratio); eventually surface area can no longer serve the requirements of the cell; this critical ratio stimulates mitosis; (thus) the size of the cell is reduced and kept within size limits; Draw a labelled diagram of a prokaryotic cell. [5] a. cell wall – uniformly thick and drawn outside the plasma membrane; b. plasma membrane – a continuous single line; c. cytoplasm/cytosol; d. nucleoid/(naked) DNA – shown as a tangle of thread or irregular shape without a nuclear membrane; e. (70S) ribosomes – drawn as a small circle or dark dot; f. pili – hair like structures / flagellum – shown to be longer than any pili; g. plasmid – circular ring of DNA; h. capsule – drawn outside the cell wall; Award [1] for each structure clearly drawn and labelled which conforms to the italicized guidelines given above.

Revision booklet including questions about all four main topics, With answers.

IB Biology SL + HL EXAM REVISION

Revision resources and summary powerpoints with questions for the AS content of OCR Biology.

Revision resources and summary powerpoints with questions for the AS content of Edexel A Biology.

Revision resources and summary powerpoints with questions for the AS content of AQA Biology.

Revision resources and summary powerpoints with questions for the AS content of AQA Biology.

Revision resources and summary powerpoints with questions for the AS content of AQA Biology.

Revision resources and summary powerpoints with questions for the AS content of AQA Biology.

Here is my IB Biology Internal Investigation. It was completed in 2019 for the May 2020 exams. It investigated this question: How does increasing the temperature of a plant impact the movement of pigment through a flowering plant?