Self-study
P1
The characteristic smell or taste of a plant, to insects as well as to humans, depends on its chemical composition. ███████ █████████ ██████ ███████ ███ ██████████ ██ ████████ ███████████ ███████ ███ ██████████ ███
Intro topic ·
Two kinds of chemicals in plants: primary and secondary
Chemicals determine smell and taste of plants to insects and humans.
Primary substances ·
Stuff required for growth and functioning; found in all plants
Secondary substances ·
No known role in growth/functioning; give plants distinctive tastes and smells
P2
███████ ██████ ██ ████ ██████ █ █████ ████ ██ ████ ███████ ██████ ███ █████████ ██████████ ████ ████ ██████ ███
Origin of secondary substances ·
Insects played major role
Causal mechanism 1 ·
Insects like some scents over others
Secondary substances result from mutations. Insects prefer some scents over others, which means the substances that produce those preferred scents are more likely to be passed on to future generations.
Causal mechanism 2 ·
Some substances produce stuff that helps defend against insects
Causal mechanism 3 ·
Some substances produce stuff that warns insects not to eat the plant
P3
███ ████████ ██ ████████ ██ █████ █████ ███ ████ ██ ████████████ ███████████ ███ █████████ ███████ ██████ ███ ████████████ ████████ ██ ███████ ███ ██ ███████ ██ ███ ██████ ████ ███ ███████ ████████ ███████ █████ ████ ████ ██████ ██ █████ █████ ██ ██████ ████ ██ ██████████ ███ ███████ █████████ ████ ███ ██████ █ ███ ██ ████████ █ ███████ ██████████ ██ █████ ██ ██ █████ ██████ ███ ██ ██████ ████ ██ ██ █████ ███ ███████ ██ ████ █████ ███████ ███████ ███████ ████ ██ ██████ ███ ██████ █████ ████████ ████ ███ ███████████ ███ ████ ██████████ ██████ ███ ███████ ██ ████████ ████ ██ █████ ██████████████ ███████ ██ ██████ ██ █████ ██ ███ ███████████ ███ ███████████ █████ ███ █████ ██████ ████ ████████ ██ ████████ ████ ███████ ███ ███ ███ ███████ ██ ███████ ███████ ██ ███████ ████ ████ ██████ ██ ██████ ██████████ ████ ████████ ███████ ███ █████ ███████████ ██████████ ██████ ██ ███████
Competition between insects and plants ·
Insects evolve to respond to plants' defenses
Might evolve way to detoxify plant's poison or store the poison in an unharmful way, for example. Might evolve way to identify poisonous plants.
Passage Style
Phenomenon-hypothesis (RC)
Single position
12.
Which one of the following █████████ █ ███ ██ █████████████ ████ ██ ████ ███████ █████████ ██ ███ █████████████ ███████ ██████ ███ █████ ███████ ███ █████████ ███████████
a
Electrical power for ███ █████████ ██ ███████ ████ ██ ██████ ███ ███████ ███████████ ██ █████████ ██ ███ ██████ ███████████ ██ ██████████ ██████████ ███ █████ ████ ██ █████████ ██ ███████ ███████████ ██ ████ █████ █████ ██████ ██ █████ ██ ███████████ ████████████
(A) describes something that’s essential for proper functioning (electrical power) and notes that generators are a backup way to provide this essential thing. But this isn’t analogous, because secondary substances aren’t a backup way to provide what primary substances provide.
b
Mechanical components such ██ ███████ ███ █████████████ ███ █████████ ███ ███████████ ██ ████ ████████ ████ ██ █████ ███ ██████████ ████ █ ███ ███ ███████████ ████ ███ █████ █████████ ████ ██ ██████████ ████ ███ █████████ ███████ ███ ███████████ ███ ███ ███████ █████
This is the most analogous. Engines and transmissions are necessary for proper functioning of a car, just as primary substances are to plants. But other features, such as paint and taillights, give the car its superficial features (the look) as well as help protect the car (preventing rust), just as secondary substances give the plant superficial features (taste and smell) and help protect the plant (defense mechanisms).
c
Mechanical components such ██ █████ ███ ██████ ███ ████████ ███ ███ █████████ ██ ████████ ██████████ ██████████ ██████████ ████ ██ █████ ███ ████████████ ██████ ███ █████ ██████ ██ ███ ███ ██████████ ███████████ ███ ████ ██ ███ ███████████ ████████ ██ ███ █████████████ ████████
(C) describes something that’s essential for proper functioning (mechanical components). But it then discusses electrical components, which are necessary to run the mechanical components. This isn’t analogous, because secondary substances aren’t necessary in order for the primary substances to work.
d
Some type of ███████ ██████ ██ █████████ ███ ██████ ██ ██ ████ ██ ██████████ ███ █████ ████ ███████ ████████ ████ ████████ ██████████ ████ ████████ ███████ ███ ███████ ██████ ███ █████████ ██████████ ████ █████ ████████ ██ ███ ████████ ███████████
(D) discusses something necessary for the proper functioning of a train — a braking system. It then discusses two components of a braking system. But this isn’t analogous, because we want discussion of something that’s not essential to the proper functioning of a train, just as secondary substances are not essential to the proper functioning of a plant.
e
Specially designed word ██████████ ████████ ███ █████████ ███ █████████ ██ ██ ████ ██ ████████ ██ ████ ███████████ ████ ████████ ███ ██ ██████ ██████ ██ ███ ██████████ ████████ ██████ ██████ ██ ██ ████████ █████ ████ ███ ████████ ███████████ ████ ███ ██████████
(E) discusses something necessary for the proper functioning of a word processor. But we don’t get a discussion of something that’s not necessary for computers to function as a word processor.