bio133 exam 2

stimulus

any change in the environment that can be detected

sensory receptor

specialized cell that detects a stimulus

transduction

conversion of a stimulus into an electrical signal

receptor potential

change in membrane potential in response to a stimulus

adaptation

decreased sensitivity to a constant stimulus over time

mechanoreceptor

receptor that detects physical forces such as touch or pressure

chemoreceptor

receptor that detects chemical stimuli

photoreceptor

receptor that detects light

thermoreceptor

receptor that detects temperature

nociceptor

receptor that detects pain

lateral inhibition

process that enhances contrast between stimuli by inhibiting neighboring receptors

behavior

an organism's response to stimuli

proximate cause

immediate mechanism causing a behavior

ultimate cause

evolutionary reason for a behavior

innate behavior

genetically programmed behavior

learned behavior

behavior modified by experience

fixed action pattern

innate behavior triggered by a specific stimulus and carried to completion

sign stimulus

cue that triggers a fixed action pattern

habituation

decreased response to repeated harmless stimulus

imprinting

learning during a critical early period

classical conditioning

learning by associating two stimuli

operant conditioning

learning through rewards and punishments

trial-and-error learning

learning by testing different behaviors

communication

transfer of information between individuals

signal

behavior or structure that conveys information

pheromone

chemical signal affecting members of the same species

visual signal

communication through visual displays

auditory signal

communication through sound

tactile signal

communication through touch

honest signal

signal that accurately reflects condition

deceptive signal

signal that misleads receiver

courtship behavior

signals used to attract mates

territorial behavior

signals used to defend an area

parthenogenesis

reproduction from unfertilized eggs

hermaphroditism

organism has both male and female reproductive organs

sequential hermaphroditism

organism changes sex during life

protogyny

female to male sex change

protandry

male to female sex change

temperature-dependent sex determination

sex determined by environmental temperature

genetic sex determination

sex determined by chromosomes

SRY gene

gene that initiates development of testes

indifferent gonads

embryonic gonads that can develop into testes or ovaries

testosterone

hormone promoting male development

external fertilization

fertilization outside the body

internal fertilization

fertilization inside the body

oviparity

eggs laid outside the body

ovoviviparity

eggs retained inside parent, nourished by yolk

viviparity

embryos develop inside parent with direct nourishment

amniotic egg

egg with membranes adapted for land development

spermatophore

packet of sperm transferred to female

claspers

male structures used to transfer sperm in some fish

monotremes

egg-laying mammals

marsupials

mammals with pouch development

eutherian mammals

placental mammals

seminiferous tubules

site of sperm production

spermatogenesis

production of sperm through meiosis

spermatogonium

diploid germ cell

primary spermatocyte

cell entering meiosis I

secondary spermatocyte

haploid cell after meiosis I

spermatid

haploid cell after meiosis II

epididymis

site of sperm maturation and storage

vas deferens

tube transporting sperm

urethra

tube carrying semen out of body

acrosome

enzyme cap that helps sperm penetrate egg

flagellum

tail used for sperm movement

Sertoli cells

support developing sperm

Leydig cells

produce testosterone

GnRH

hormone from hypothalamus that stimulates pituitary

FSH

hormone stimulating sperm production

LH

hormone stimulating testosterone production

inhibin

hormone that inhibits FSH

penis

organ that delivers sperm

erectile tissue

tissue that fills with blood during erection

nitric oxide

molecule causing blood vessel dilation

ejaculation

release of semen

ovary

organ producing eggs

fallopian tube

site of fertilization

uterus

organ where embryo develops

cervix

opening of uterus

vagina

canal for sperm entry and birth

follicular phase

phase of follicle development

Graafian follicle

mature follicle

ovulation

release of egg

luteal phase

phase after ovulation

corpus luteum

structure producing hormones after ovulation

endometrium

uterine lining

menstrual phase

shedding of uterine lining

proliferative phase

rebuilding of uterine lining

secretory phase

preparation of uterus for implantation

hCG

hormone maintaining corpus luteum

implantation

embedding of embryo in uterus

placenta

organ for nutrient exchange

estradiol

estrogen hormone in cycle

progesterone

hormone maintaining uterine lining

contraception

prevention of pregnancy

abstinence

no sexual intercourse

condom

barrier preventing sperm entry

diaphragm

barrier covering cervix

oral contraceptives

hormones preventing ovulation

IUD

device preventing implantation