excretion Flashcards
define excretion
the removal of waste products of metabolism out of the body
give 3 organs that are apart of the excretion system in animals
lungs, kidneys, skin
give an example of a feature in plants that is involved in excretion
stomata
what is crenation
when water leaves an animal cell due to osmosis and shrinks
name two methods animals control their temperatures
ectotherms, endotherms
what is an ectotherm
gain/lose heat to or from an external environment e.g fish, frogs, snakes
what is an endotherms
generate their own heat from metabolic reactions. e.g cats
how does the skin help achieve homeostasis
it regulates human body temperature
name the two layers of skin
epidermis, dermis
what is the name of the layer found beneath the epidermis + dermis
subcutaneous tissues which contain adipose tissue (fat-rich cells)
what names are given to the layer of cells that make the epidermis
malphighian layer, granular layer, cornified layer
where is melanin produced
malphighian layer
where is keratin produced
granular layer
what’s the purpose of melanin
gives colour to the skin, hair and iris + protects the skin from UV rays
in what scenario might a lot of melanin be produced
when the skin is subjected to more sunlight exposure