Draw a labelled diagram to show the fluid mosaic model of the plasma membrane.

Unicellular and multicellular organisms share the same functions of life. Outline four functions of life.

The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.

a. two correctly oriented layers of phospholipids/phospholipid bilayer shown with heads facing in opposite directions 

b. phospholipids shown with two parts labelled hydrophilic/phosphate head AND hydrophobic/hydrocarbon tail

c. protein (any) shown as a globular structure embedded in one/both layers of phospholipid 

d. peripheral protein, shown as globular structure at the surface of the membrane AND integral protein shown as embedded globular structures 

e. glycoprotein shown as embedded globular structure with antenna-like carbohydrate protruding / carbohydrate shown as a branched/antenna-like structure either on a protein or on a phospholipid
OR
channel protein(s) shown with a pore passing through it
OR
pump protein shown as a transmembrane globular structure 

f. cholesterol shown in between adjacent phospholipids

Do not award the mark unless the structure is labelled with the underlined name.

a. nutrition: process by which organisms take in and make use of food//nutrients OWTTE 

b. metabolism: conversion of organic molecules/chemical reactions in an organism 

c. growth: increase in size/mass/number of cells within an organism

d. response/irritability/sensitivity: reactions/responsiveness to stimuli/factors 

e. homeostasis: regulating/maintaining constant/stable interior environment 

f. reproduction: production of similar cells/organisms from existing ones/offspring 

g. excretion: elimination of (metabolic) wastes

a. autotrophs/producers absorb carbon (dioxide} from atmosphere/air/water 

b. autotrophs make carbohydrates/organic compounds / perform photosynthesis 

c. carbon (compounds) pass along food chains/trophic levels (as consumers feed) 

d. respiration releases carbon (dioxide) into atmosphere/water 

e. carbon (dioxide} is released from dead matter /by decomposition/respiration 

f. methane is produced during anaerobic respiration of organic matter / by methanogens in cattle/herbivores

g. methane is oxidized into carbon dioxide in the atmosphere 

h. fossil fuels/peat were made from partially decomposed organic matter 

i. combustion of fossil fuels/forest fires/biomass releases carbon (dioxide} into the atmosphere 

j. volcanic eruptions may add large quantities of carbon (dioxide) into the atmosphere 

k. limestone (from shells/reefs)/trees/permafrost are sinks of carbon