First Hand Investigations
i) Maintaining a Balance
· identify data sources, plan, choose
equipment or resources and
perform a first-hand investigation
to test the effect of:
– increased temperature (e.g. potato/liver catalase in water baths etc.)
– change in pH (e.g. potato, catalase, different amounts of acid or base added, keep volumes the same)
- substrate concentrations on the activity
of named enzyme(s) (e.g. liver,catalase, different amounts of peroxide and water, same volumes, same diameter tubes)
· perform a first-hand investigation
to demonstrate the effect of
dissolved carbon dioxide on the
pH of water(pH meter, bubbled into water, pH went down)
· perform a first-hand investigation
using the light microscope and
prepared slides to gather
information to estimate the size
of red and white blood cells and
draw scaled diagrams of each (measure diameter of field of view in mm with a ruler, multiply by 1000 to get micrometres, divide by number of cells going across slide- rbcaround 7 micrometres, wbc around 12-16 micrometres)
· choose equipment or resources to
perform a first-hand investigation
to gather first-hand data to draw
transverse and longitudinal
sections of phloem and xylem tissue
· perform a first-hand investigation of
the structure of a mammalian kidney
by dissection, use of a model or
visual resource and identify the
regions involved in the excretion of
waste products(know where cortex, medulla, pelvis, ureter, urethra are and what part of nephron is in each)
· perform a first-hand investigation to
gather information about structures
in plants that assist in the
conservation of water (e.g. fleshy leaves in pigface, succulents, hairy coverings, waxy coatings, needle like leaves in some natives)
ii) Blueprint of Life
· plan, choose equipment or
resources and perform a first-hand
investigation to model natural
selection (green and brown toothpicks thrown on grass; the environment/green background is the selecting agent- more brown toothpicks were ‘preyed’ upon because they were easier to spot by the predators (us).)
· perform a first-hand investigation
or gather information from
secondary sources (including
photographs/ diagrams/models)u to
observe, analyse and compare the
structure of a range of vertebrate
forelimbs (here they are; suggest a common ancestor)
· perform an investigation to
construct pedigrees or family trees,
trace the inheritance of selected
characteristics and discuss their
current use (you did this in your research task, and wrote questions on them)
· identify data sources and perform a
first-hand investigation to
demonstrate the effect of
environment on phenotype ( we investigated the effect of fertiliser on growth of shallots – remember 3-5 plants per pot, different amounts of fertiliser in each pot, dependent variable is height of plants)
· perform a first-hand
investigation or process
information from secondary
sources to develop a simple
model for polypeptide synthesis (remember the DNA code was on the board, you drew the corresponding mRNA code and took it to the ribosome at the side of the room to get the corresponding tRNAs and their amino acids. This was in the prac. Test, too)
iii) Search for Better Health
· identify data sources, plan and
choose equipment or resources to
perform a first-hand investigation to
identify microbes in food or in water (we inoculated agar plates with pond water, fresh water etc., sealed them and incubated them at around 30 degrees for a few days. We counted the number and type of each colony – bacteria are shiny, fungi are furry etc.-nb sterile techniques)
· perform an investigation to model
Pasteur’s experiment to identify
the role of microbes in decay (swan neck flasks and open neck flasks; boil broth to kill existing microbes and leave to stand. Swan necked flasks did not decay nb: safety considerations)
· identify data sources, plan and
perform a first-hand investigation
or gather information from
secondary sources to analyse and
present information about the
occurrence, symptoms, cause,
treatment/management of a named
non-infectious disease (really a secondary source exercise- examples: Down syndrome, scurvy, lead poisoning etc.))
· perform an investigation to
examine plant shoots and leaves
and gather first-hand information
of evidence of pathogens and insect
pests (e.g. powdery mildew (a fungus) on Impatiens, Crepe Myrtle, Lacebug(an insect) on azalea leaves, smut and rust(fungi) on wheat, aphids (insects) on roses)