Transcript Plant and Animal Behavior

Plant and Animal Behavior
Adapted from Chapters 26 and 36
in Holt Biology
Plant and Animal Behavior
Objectives
Plant and Animal Behavior
• Assess and examine plant tropisms and other
responses including: phototropism, thigmotropism,
geotropism.
• Evaluate the survival of organisms and suitable
adaptive responses to environmental pressure such
as: parental behavior, responses to environmental
change.
• Assess, describe and explain types of animal
behaviors such as: chemotaxis, phototaxis, reflexes,
imprinting, and types of learned behavior.
• Analyze the biological clocks and rhythmic behavior
of organisms.
• Evaluate and explain the evolution of behavioral
adaptations and survival of populations.
Plant Hormones and
Response
Plant Hormones and Response
PLANT HORMONES
• Hormones = chemicals that are produced in
one part of an organism and transported to
another part, where it causes physiological
change.
– Auxins – promote cell elongation
• Accumulate on dark side of a stem causing
those cells to elongate more than cells on the
light side.
• Cause stems to bend toward light.
– Gibberellins – plant growth hormone
• Stimulate cell elongation
• Increase rate of seed germination
• Increase rate of bud and fruit development
The Went Experiment
Some chemical that can pass
into an agar block from the tip
stimulates elongation of the
shoot when the block is
substituted for the tip. If the
block is place off-center on the
top of the decapitated shoot
kept in the dark, the shoot
bends as if responding to
illumination from one side.
The chemical is the hormone
auxin, which stimulates
elongation of cells in the shoot.
Effect of Gibberellins
The plant on the right was treated with gibberellin. The
plant on the left was not. This effect is seen only in
dwarf plants.
Plant Hormones and Response
– Cytokinins –stimulate cell division and
slow the aging of some plant organs.
– Ethylene gas –speeds ripening of fruit
PLANT RESPONSES
• Tropism
– Response to external stimulus that comes
from a particular direction.
– Positive tropism—plant grows toward the
stimulus
– Negative tropism—plant grows away from
the stimulus
Plant Hormones and Response
– Types
• Phototropism – response to light
(positive)
Plant Hormones and Response
– Types
• Gravitropism (aka geotropism) –
response to gravity
–Positive in roots
–Negative in stems
Plant Hormones and Response
– Types
• Thigmotropism – response to touch
Plant Hormones and Response
• Nastic responses – not dependent on
the direction of stimulus (response of
hinged leaf of Venus fly trap is example)
Plant Hormones and Response
• Photoperiodism
– Refers to the response of flowering plants
to differences in the duration of light and
dark periods in a day.
– Controls flowering
Animal Behavior
Animal Behavior
• Behavior
– Anything an animal does in response to a
stimulus in its environment.
– Environmental stimuli such as day length
and temperature can affect animal
behavior.
• Inherited behavior
– Behavior affects an animal’s ability to
survive. Such behaviors are favored by
natural selection
– Inherited behaviors are called innate
behaviors
Animal Behavior
• Taxes (tax-eez)
– Are behaviors that involve movement toward or away
from a stimulus.
• Movement toward a stimulus is described as a
positive taxis.
• Movement away from a stimulus is described as a
negative taxis.
– Types
• Phototaxis—response to light
• Gravitaxis (geotaxis)—response to gravity
• Thigmotaxis—response to touch
• Thermotaxis—response to temperature
• Chemotaxis—response to chemicals
Animal Behavior
• Innate Behaviors
– Reflex = a simple automatic response that involves no
conscious control.
– Instinctive Behavior
• An instinct
– Is a complex pattern of behavior
– May have several parts
– May take weeks to complete
• Types of instinctive behavior
– Courtship behavior
– Territoriality
– Aggressive behavior
– Dominance hierarchies
– Rhythmic behaviors
Animal Behavior
• Courtship behavior
– The behavior that males and females of a species
carry out before mating.
– Insures that individuals of a species can recognize
one another.
• Territoriality
– An animal may establish, maintain, and defend a
specific territory.
– A territory is a physical space an animal defends
against all other members of the same species.
– May contain the animal’s breeding area, feeding
area, and/or potential mates.
– May be marked by pheromones (chemicals that
communicate information among individuals of the
same species)
Courtship behaviors may involve:
Food sharing
Elaborate “dances”
Territorial behavior often involves ritual displays
Animal Behavior
• Aggressive Behavior
– Used to defend young, territory, and/or
food resources.
– Usually symbolic, not intended to cause
injury
– Includes: bird calls, teeth baring, growling
• Dominance hierarchy – a form of
social ranking within a group in which
some individuals are more subordinate
than others (pecking order)
Animal Behavior
• Rhythmic Behaviors
– Circadian rhythm – behavior based on a
24-hour day/night cycle such as wakesleep cycle.
– Migration
• It is the instinctive seasonal movement
of animals.
• May be seasonal or yearly.
• May be in response to changing day
length, temperature, or hormones
Animal Behavior
– Hibernation – a state of reduced
metabolism that occurs in animals during
cold winter months.
– Estivation – a state of reduced
metabolism that occurs in animals living in
conditions of intense heat.
• Learned Behavior
– Takes place when behavior changes
through practice or experience
Animal Behavior
– Types of Learned Behavior
• Habituation
• Imprinting
• Trial and Error Learning
• Conditioning
• Insight
• Communication
• Habituation
– A simple form of learning
– When an animal is repeatedly given a
stimulus that is not associated with any
punishment or reward it finally stops
responding to the stimulus
Konrad Lorenz with his imprinted geese
If newly-hatched geese are exposed to a moving object of
reasonable size and emitting reasonable sounds, they will begin to
follow it just as they would normally follow their mother.
Animal Behavior
• Imprinting
– A form of learning in which an animal forms
a social attachment to another object.
– Occurs at a specific, critical time of its life.
• Trial and error learning
– Occurs through experience, trying one
solution and then another.
– The animal receives a reward for making a
particular response.
Animal Behavior
• Trial and error learning (cont.)
– Happens more quickly when motivation is
involved.
• Motivation is an internal need that
causes an animal to act.
• Motivation is necessary for learning to
take place.
• Conditioning
– Is learning by association
– An animal begins to respond to a stimulus
other than the one that normally initiates
that response.
Conditioned Behavior
In the example shown here, the pigeon — presented with two spots of light
— pecks at the brighter and reaches down to pick up the grain of food that is
its reward.
Animal Behavior
• Insight
– The most complex type of learning.
– Learning in which an animal uses previous
experience to respond to a new situation.
– Involves reasoning, the ability to analyze a
problem and think of possible solutions.
– Much human learning is based on insight
Animal Behavior
• Communication
– An exchange of information that results in
a change of behavior
– Several channels of communication
• Sound
• Sight
• Touch
• Smells
– Involves both innate and learned behavior
– Language – the use of symbols to
represent ideas
Plant and Animal Behavior
Adapted from Chapters 26 and 36
in Holt Biology