Included organisms range from unicellular microalgae, such as Chlorella, Prototheca and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to  in length.
ɪŋklˈuːdᵻd ˈɔːɹɡənˌɪzəmz ɹˈeɪndʒ fɹʌm jˌuːnɪsˈɛljʊlɚ mˈaɪkɹoʊˌælɡiː, sˈʌtʃ ɐz kloːɹˈɛlə, pɹˈoʊɾoʊθˌɛkə ænd ðə dˈaɪəɾəmz, tə mˌʌltɪsˈɛljʊlɚ fˈɔːɹmz, sˈʌtʃ ɐz ðə dʒˈaɪənt kˈɛlp, ɐ lˈɑːɹdʒ bɹˈaʊn ˈælɡə wˌɪtʃ mˈeɪ ɡɹˈoʊ ˌʌp tʊ ɪn lˈɛŋθ.