Lecture 24 - Signals Flashcards
1
Q
describe the three steps of a signalling cascade
A
2
Q
explain cellular-level signaling in animals
A
hormones regulate development (except in simplet invertebrates)
- > synthesized in endocrine glands
- > secreted to extracellular fluid
- > transported by circulatory system or though diffusion
3
Q
explain cellular-level signaling in plants
A
photohormones regulate development
- > synthesized throughout, although some are produced in certain tissues
4
Q
characteristics of animal and plant hormones
A
Few plant hormones
- > each elicit a variety of responses and usually work together with other hormones
Many animals hormones
- > each has specific action and cooperation is not essetial
5
Q
cellular level signaling within unicellular organisms
A
quorum sensing
- > bacterial communication coordinating gene expression based on population density
- > a higher population will express certain genes more
6
Q
four functions of sensory pathways
A
sensory reception
- > detection of stimulus by sensory receptor (organ or cell)
sensory transduction
- > change of stimuli into membrane potential of sensory receptor
transmission
- > action potentials or nerve impulses travel trough the nervous system to the CNS
perception
- > processing of the input
7
Q
how do organisms receive signals from the environment
A
- > they sense pressure(touch), gravity, sound, temp, chemicals, electromagnetic radiation
- > cue to direct growth and behaviour
8
Q
how do organisms send signals to other organisms within vs between species
A
within species
- > mating, survival and cooperation
between species
- > survival
- > organisms communicate to establish and protect symbiotic relationships
9
Q
photochromes are _____________
A
crucial photoreceptor
- > photochrome red quickly converts to photochrome far red but photochrome far red slowly converts to photochrome red
