WGU D877 Gen Bio II - Competency 3

cell differentiation

process by which a cell becomes specialized to a perform a specific function

stem cell division

stem cells divide to produce identical daughter cells with potential to become any type of cell

cell type commitment

internal & external signals trigger stem cell to commit to specific cell type (chemical cues, growth factors, interactions with nearby cells)

gene activation & regulation

specific genes are turned on/off within a cell’s DNA to determine cell’s future structure & function

morphological changes

cell undergoes structural changes, either in shape or in production of specific proteins

functional maturation

cell develops its final characteristics and begins performing its specialized function

cell signaling

how cells communicate to regulate various functions and respond to changes; essential for cell differentiation

totipotent

embryonic stem cells are __________; can become almost any cell type in the body (growth & development)

multipotent

adult stem cells are ___________; can become a limited number of cell types (healing & tissue repair)

pluripotent

induced ___________ stem cells; can become several different cell types due to scientists reprogramming regular adult cells to act like embryonic stem cells

gravitropism

gravity stimulus; roots grow downward & stems grow upward

thigmotropism

touch stimulus; vines wrap around structures for support

phototropism

light stimulus; stems and leaves grow toward light to optimize photosynthesis

hydrotropism

water stimulus; root grow toward moisture sources

reflex action

touch stimulus; immediate movement of a limb [removing hand from hot stove]

phototaxis

light stimulus; movement toward or away from light [moths finding light]

chemotaxis

chemical signals; movement toward or away from chemicals [bees finding flowers]

thermoregulation

temperature changes; adjusting body temperature [dogs panting, humans sweating]

auditory response

sound stimulus; turning head toward sound [rabbits freezing to listen]

chemical communication

pheromones; initiating mating behavior

autocrine signaling

cells produce signaling molecules that bird to receptors on the same cell, initiating a response

paracrine signaling

cells sending signals to nearby, neighboring cell

endocrine signaling

cells secrete hormones into the bloodstream, allowing for long-distance communication with target cells in different parts of the body

cell surface receptors

on outside of cell— helps the cell sense things like chemicals or ions

intracellular receptors

inside the cell— bind with molecules that can pass through the cell’s outer layer

quorum sensing

signaling molecules trigger collective behavior in unicellular organisms, bacteria

positive feedback loop

works to amplify a change in specific situations [oxytocin in childbirth, blood clotting]

negative feedback loop

works to reverse a change and restore balance [regulating body temp, blood sugar]

signal transduction

conversion of a signal into a cellular response, like turning proteins/enzymes/hormones on and off

neurons

transmit electrical signals rapidly across body

neurotransmitters

chemicals released by neurons to pass signals to other nerve calls [at synapses]

synapses

junctions of neurons where neurotransmitters are released

rapid communitcation

type of communication needed for reflexes, pain & danger reactions, and control of movement

nervous system

sends info swiftly through electrical impulses traveling along specialized cells enabling rapid responses to stimuli

endocrine system

send info through hormones that travel throughout the bloodstream to regulate various long-term processes

chemical messengers produced by the thyroid, pituitary, and adrenal glands to target specific cells and exert effects

avoiding predators

a purpose of communication in animals— warning calls, camouflage, defensive postures, bright colors, & chemical warning

finding mates

a purpose of communication— specific calls & visual signals in animals; flowering pattern & scents in plants

collaboration

a purpose of communication in animals— chemical signals or cooperation

cerebrum

largest part of brain— responsible for higher brain functions like thought, learning, memory, and voluntary movement

frontal lobe

reasoning, planning, motor control, & speech production

parietal lobe

sensory processing & spatial awareness

temporal lobe

auditory processing, memory, & language comprehension

occipital lobe

visual processing

prefrontal cortex

decision-making & emotional regulation

cerebellum

back/base of the skull— coordinates movement, balance, & posture

diencephalon

between cerebrum and brainstem— relay & processing center for sensory information and automatic control

brainstem

connects brain to spinal cord—