Class Notes (837,539)
Canada (510,303)
Biology (2,271)
BIOL 165 (39)

Biol 165 - Kingdom Protoctista.pdf

5 Pages
Unlock Document

BIOL 165
Kirsten Muller

Biol 165: Diversity of Life 2013-04-21 2:36 PM Kingdom Protoctista Introduction • Protists are a paraphyletic group (ie, even some algae are included in the group). • DNA/RNA studies indicate that it is a complicated group comprised of serial endosymbiotic events. • most methods of classifying them prove to be inconvenient and not easily accommodating to their differences. • each phylocode solves some problems while creating others. • Protists can be found in each of the 6 Eukaryote Supergroups: o SuperGroup Opisthokonta o SuperGroup Chromalveolata o Supergroup Planta • The 3 groups of “primitive” Protozoan (unicellular eukaryote) groups: o SuperGroup Amoebozoa (amoebae and slime molds) o SuperGroup Excavata (basal flagellates) o SuperGroup Rhizaria SuperGroup Amoebozoa • Is a primitive kind of protist • They move using pseudopodia, and the mode of travel is called amoeboid locomotion. • They obtain food by phagocytosis Phylum Pelobonta Genus Pelomyxa • giant, and free-living • multinucleate and herbivorous • most primitive protist known; it lacks most organelles Other Species: Phylum Rhizopodia • Amoeba proteus o large and carnivorous o common in fresh water, and even cracks in pavement • Entamoeba histolytica o causes Amoebic dysentery Cell Division: 3 Kinds • Promitosis o the nuclear membrane and nucleolus remains intact. o Chromosomes are not clear. • Mesomitosis o nuclear membrane is intact, but nucleolus disintegrates o there are no centrioles, and spindle fibres terminate at nuclear membrane • Metamitosis o typical mitosis occurs including nuclear membrane loss o spindle fibres converge and operate w/o centrioles o chromosomes are recognizable. Cellular “Slime Molds” • ie, Phylum Acrasea and Phylum Dictyotstelida • Cellular slime molds spend most of their life cycle as free living individual haploid protists. • Only when food is scarce do they aggregate to form a sporangium to release microcysts. • The new microcysts release amoeboid cells, which can fuse to for a macrocyst. • The macrocyst will then divide by meiosis to produce two haploid, free-living amoeboid daughter cells. • Cellular Slime Molds have a heteromorphic life cycle – different appearances during life cycle. • Plasmodial Slime Molds (PSM)/Acellular Slime Molds • Phylum Myxostelida • Genus Stemonitis and Lycogala • PSM are enormous single cells with thousands of nuclei • They are formed by the fusion of numerous individual flagellated cells. • They also form sporangia/fruiting bodies, and disperse spores. SuperGroup Excavata – Basal Flagellates • considered to be the most primitive of protists • many are disease causing, or parasitic • ie, Chagas disease, African Sleeping Sickness, leishmaniasis, some STDs. • Amoebaflagellates o Phylum Amoebgoflagellata o have both amoeboid and flagellate stages in life cycle o amoeboid stage lives in soil, normally only stage that can feed. o flagellated stage lives in pools of water
More Less

Related notes for BIOL 165

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.