Detection and Response (CH 40, 42, 43) Flashcards
What is the name of the light sensing protein?
What is this responsible for?
phytochrome
plant growth responses
What are the three plant growth responses?
- ) seed germination
- ) shoot elongation
- ) detection of plant spacing
*look at slide for red light vs. far red light associations
the bending of growing stems to sources of light with blue wavelengths (460-nm range) is associated with what?
phototropin
which cells sense gravity?
endodermal cells
how do plants move?
cell surface proteins, water potential, and plant hormones
What are the 5 plant movements?
Photomorphogenesis Thigmomorphogenesis phototropism thigmotropism gravitrophism
What is Photomorphogenesis?
permanent light-triggered development
What is Thigmomorphogenesis?
permanent touch triggered responses
What is phototropism?
directional growth responses to light
What is Thigmotropism?
directional growth responses to mechanical stimuli
What is Gravitrophisms?
directional growth responses to earth’s gravity
touch induced plant movements involve reversible changes in what?
What is another name for these cells?
turgor pressure
pulvini
What are examples pf touch related turgor?
snapping of the venus flytrap
curling of tendrils
What is an example of a plant that undergoes light related turgor?
bean leaves
what are the two types of gravitropism and give an example
negative = shoots positive = roots
what is responsible for the curvature of stems upwards and asymmetrical cell elongation?
Auxin
what is abscission?
when a plant drops its leaves or petals to conserve resources
True or False:
in plants hormones are produced by specialized tissues?
False
one of the effects of auxin is an increase in__________
plasticity of the plant cell wall
What do cytokinins do?
stimulate cell division and differentiation
there is a plant pathogen called Agrobacterium that introduces genes into the plant genome that increase the production of cytokinins and auxins. What does this cause in the plant?
massive cell division and formation of a crown gall tumor
Whats the name of the 100+ naturally occurring plant hormones?
gibberellins
what do gibberellins do?
hasten seed germination
*used commercially to extend the internode length in grapes resulting in larger grapes
what does ethylene do?
retards growth
- suppresses stem and root elongation
- controls lead, flower, and fruit abscission
- hastens fruit ripening
True or False:
Abscisic Acid counteracts gibberellins and auxin
true
Why is Abscisic Acid important?
2 things
necessary for dormancy in seeds and important in opening and closing the stomata
Animal responses to the environment involve which three systems?
Endocrine, Sensory, Nervous
What do exteroceptors do?
sense external stimuli
ie: smells, taste
What do Interoceptors do?
sense internal stimuli
ie: temperature, pH
what stimulates mechanoreceptors?
mechanical forces such as pressure
What do chemoreceptors do?
detect chemicals or chemical changes
What do energy-detecting receptors do?
react to electromagnetic and thermal energy
Sensory cells respond to stimuli via _________ in their membranes
stimulus-gated ion channels
There are 5 specific mechanoreceptors that we need to know for this exam. What are they?
Nociceptors Thermoreceptors Proprioceptors Baroreceptors Sensory Hair cells
Describe Nociceptors
- transmit impulses based on cell damage
- perceived as pain
- mostly free nerve endings
Describe Thermoreceptors
- naked dendritic endings of sensory neurons
- sensitive to changes in temperature
- contain ion channels that are responsive to hot and cold
- Cold receptors are located higher in the skin, and are much more numerous than warm receptors
Describe Proprioceptors
- monitor muscle length and tension
- provide information about the relative position or movement of animal’s body parts
Describe Baroreceptors
- monitor blood pressure
- branched network of afferent neurons in the carotid sinus and aortic arch
- detect tension or stretch in the walls of these blood vessels
Describe Sensory Hair cells
- specialized cells named stereocilia that have cytoplasmic extensions
- when they bend, stereocilia send action potential to a sensory neuron
- responsible for several senses including water current, hearing, and balance
explain the lateral line system in fish
- Canals run the length of the fish’s body beneath the skin surface
- contain hair cells in a gelatinous cupula
- innervated by sensory neurons that transmit impulses
- bending of stereocilia detects currents
What is hearing?
the detection of vibrations that is perceived as sound
involves stereocilia
What are the advantages of hearing?
- auditory stimuli travel farther and faster than chemical ones
- auditory receptors provide better directional information than chemoreceptors
describe how sound is interpreted via the cochlea (organ of Corti)
- Has a basilar membrane with hair cells
- vibrations of the basilar membrane’s hair cells press the stereocilia against the tectorial membrane
- send serve impulses to the brain where they are interpreted as sound
A few mammals have the ability to perceive presence and distance of objects by sound. What is this called? Give an example of an animal that does this.
Echolocation
bat, shrews, whales, dolphins
In vertabrates, the gravity receptors consist of two chambers in the membrous ______
labyrinth
**look over balance and acceleration slide (40-42)
Chemoreceptors are responsible for what?
our sense
- taste
- smell
- blood composition
What is the act of tasting called?
Gustation
what are the five receptor types of taste?
sweet, sour, salty, bitter, and umami (glutamate)
collections of chemosentitive cells associated with afferent neurons are known as what?
taste buds
The act of smelling is called what?
olfaction
smell involves what?
neurons located in the upper portion of the nasal passages
How many smell receptors do humans have?
How many smells can we discern?
400
trillion
Peripheral chemoreceptors and central chemoreceptors have to do with what?
pH
*look at slide 47
Vision begins with the capture of light energy by _________
photoreceptors
Many invertebrates have photoreceptors clustered in an_______
eyespot
What are the four phyla that have developed image forming eyes?
annelids, mullusks, arthropods, chordates
The vertebrate retina contains two types of photoreceptors. What are they and describe them
Rods: black and white vision when illumination is dim
Cones: color vision and high visual acuity (sharpness)
-most are located in the central region of the retina
What photopigment do rods have?
What photopigment do cones have?
rods have rhodopsin
cones have photopsin
*each has a different amino acid sequence
Carnivores have 2 types of cones and are called______
Humans have 3 kinds of cones and are called______
Birds have 4 kinds of cones and are called______
dichromats
trichomats
tetrachromats
What can birds see that we can’t?
ultraviolet
______ a transparent structure that completes focusing of light onto the______
lens; retina
What is the only vertebrate that can sense infrared radiation? What does it help them do?
snakes (have pit organs on either side of the head)
locate heat sources in the environment (prey in darkness)
Elasmobranchs (sharks, rays, skates) have electroreceptors that makes them able to do what?
sense electrical currents generated by the muscle contractions of their prey
**(Ampullae of Lorenzini)
What is magnetoception?
a sense which allows an organism to detect the magnetic field lines of the Earth
-explains how birds migrate
The nervous system links which 2 things?
sensory receptors and motor effectors
What does the central nervous system consist of?
spinal cord and brain
What does the peripheral nervous system consist of?
sensory and motor neurons
Which phylum doesn’t have nerves?
sponges
Cnidarians have the simplest nervous system. Describe it
neurons are linked to each other in a nerve net
- no association neurons
- one big reflex machine
almost all other nervous systems of invertebrates are similar to that of the platyhelminth model. What are 3 characteristics of this model?
- 2 nerve cords run down the body
- permit complex muscle control
- rudimentary ‘brain’
