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Led by William Harvey Simulacrum
The second module of the OCR GCSE Biology A course — cell transport, cell division and stem cells, the circulatory system, and plant transport. Hosted by William Harvey Simulacrum.
Led by William Harvey Simulacrum
The question
How cells move substances across their membranes — diffusion, osmosis and active transport. Covers the direction of movement and energy requirements for each mechanism, concentration gradients, the concept of water potential, and examples of substances that enter and leave cells by each route.
Outcome
The student can explain how substances are transported into and out of cells through diffusion, osmosis and active transport. (Cell transport)
Sub-units
Led by William Harvey Simulacrum
The question
How one fertilised egg becomes thirty-seven trillion cells — the cell cycle, mitosis, cell differentiation into specialised cell types, and the role of stem cells (embryonic and adult) in development, growth and repair. Includes the difference between embryonic and adult stem cells and the presence of meristems in plants.
Outcome
The student can describe the cell cycle and mitosis, explain cell differentiation with examples, and describe the functions and differences of embryonic and adult stem cells. (Cell division and specialisation)
Sub-units
Led by William Harvey Simulacrum
The question
Why multicellular organisms need specialised exchange surfaces and transport systems — the surface area to volume ratio problem. Covers the structure and function of the human heart (valves, chambers, cardiac muscle), the double circulatory system, the structure of blood vessels (arteries, veins, capillaries), and how red blood cells and plasma are adapted for transport.
Outcome
The student can explain the need for transport systems using surface area to volume ratio, and describe the structure and function of the heart, blood vessels and blood. (Circulatory system)
Sub-units
Led by William Harvey Simulacrum
The question
How plants move water and dissolved food without a pump — root hair cells, the xylem and phloem, transpiration and translocation, the structure and function of stomata, and the environmental factors that affect the rate of water uptake. Includes the use of a potometer to investigate transpiration rates.
Outcome
The student can explain how plants take up and transport water and minerals through xylem and food through phloem, and describe how environmental factors affect transpiration rate. (Plant transport)
Sub-units