DECEMBER 4 QUIZ

Protists - Echinodermata

Protist

diverse assembly of organisms that defy the conventional classification of life into animals, plants, fungi, and bacteria

Protist

encompasses a vast range of mostly singlecelled entities, though it also includes complex multicellular organisms like the giant kelp

Animal-like Protists (Protozoa)

type of protists that eat food like animals do.

Animal-like Protists (Protozoa)

amoeba, ciliates, flagellates is what type of protist

Plant-like Protists (Algae)

type of protist that make food from sunlight like plants; Photosynthetic, contain chloroplasts, and produce oxygen

Plant-like Protists (Algae)

diatoms, dinoflagellates, and kelp is what type of protist

Fungus-like Protists

type of protist that decomposers (break down plants and animals)

Fungus-like Protists

slime mold is what type of protist

Animal-like Protists (Protozoa)

type of protist that is unicellular, eukaryotic, heterotrophic organisms (feed by phagocytosis)

Animal-like Protists (Protozoa)

either free-living or parasites; either free-living or parasites

Animal-like Protists (Protozoa)

most are too small to be seen by the naked eye; best seen under the microscope ● live anywhere there is water, such as in damp soil, leaf litter, and also inside and on the bodies of multicellular animals

Animal-like Protists (Protozoa)

alternates between dormant cyst stage and proliferating vegetative stage, e.g. trophozoites

Cysts stage

stage in protists where they survive harsh conditions without water and nutrients; can remain outside the host for a longer duration and get transmitted

Trophozoite stage

stage in protists where infectious and feed and multiply during this stage

Animal-like Protists (Protozoa)

most reproduce by asexual means: fission, budding - some by sexual reproduction: conjugation, syngamy

Sarcomastigophora or Flagellated protozoans

parasites or free-living ● have flagella for locomotion ● body covered by a cuticle or pellicle ● freshwater forms have a contractile vacuole ● reproduction: binary fission (longitudinal division)

Sarcomastigophora or Flagellated protozoans

Examples: Trypanosoma, Trichomonas, Giardia, Leishmania, etc

Sarcodina or Amoeboids

live in the freshwater, sea or moist soil ● move by pseudopodia; capture their prey by pseudopodia ● no definite shape and pellicle is absent ● contractile vacuole is present in the amoeboids living in freshwater ● reproduction: binary fission and cyst formation

Sarcodina or Amoeboids

examples: Amoeba, Entamoeba, etc.

Apicomplexa or Sporozoans

endoparasitic ● don’t have any specialised organ for locomotion ● pellicle is present, which has subpellicular microtubules, that help in movemen

Pellicle

a thin skin or film covering some protozoans

Apicomplexa or Sporozoans

Examples: Plasmodium, Myxidium, Nosema, etc

Ciliophora or Ciliated protozoans

aquatic and move actively with the help of thousands of cilia ● with fixed shape due to covering of pellicle ● may have tentacles, e.g. in the sub-class Suctoria ● contractile vacuoles are presen

Ciliophora or Ciliated protozoans

some species have an organ for defence called trichocysts ● move with the help of cilia and the movement of cilia also helps in taking food inside the gullet ● reproduce by transverse division and also form cysts

Ciliophora or Ciliated protozoans

Examples: Paramecium, Vorticella, Balantidium, etc.

Phylum Porifera

Porifera means pore-bearing

Asconoid Sponge - Leucoselenia

Has the simplest organization ● Choanocytes line the spongocoel, drawing water through small openings called ostia and expelling it through the osculum.

Syconoid Sponge - Scypha

Has a tubular design but the body wall is folded ● The fold form radial canals and incurrent canals. ● Choanocytes line the radial canals rather than the spongocoel

Leuconoid - Bath Sponge

Most complex body form ● The canal system is extensively branched. ● Small incurrent canals lead to the flagellated chambers lined by choanocytes. ● Flagellated chambers discharge water into excurrent canals that eventually lead to an osculum.

Class Calcarea

Spicules composed of calcium carbonate ● Spicules are needleshaped ● Body form: ascon, leucon, or scyon ● All marine

Class Hexactinellida

Spicules are six-rayed composed of silica ● Spicules often fused into an intricate lattice, cup, or vaseshaped ● Body form: leucon, or scyon ● Found at 450 to 900 m depths in tropical West Indies and eastern Pacific

Class Demospongiae

Brilliantly colored sponges with needle-shaped or four-rayed siliceous spicules or spongin ● Body form: leucon up to 1 meter in height and diameter ● Includes one family of freshwater sponges Spongillidae, and the bath sponges.

Class Homoscleromorpha

Anatomically simple and encrusting in form. ● Siliceous spicules small and simple in shape or absent ● Occur at depths ranging from shallow marine shelves or depths of 1000 meters

Nematodes

commonly referred to as roundworms, threadworms, or pinworms

Pseudocoelomates

organisms that have false body cavities

Nematodes

Pseudocoelomates (organisms that have false body cavities) ● Bilaterally symmetrical cylindrical body with triploblastic nature. ● Alimentary canal is simple straight tube. Mouth at anterior end and anus at the posterior end. ● Digestion is both extracellular and intracellular. ● Intestine is non muscular. ● Blood vascular system is absent.

Sexual dimorphism

condition where sexes of the same species exhibit different morphological characteristics, including characteristics not directly involved in reproduction

thread form

nematos-eidos

Nematodes

Body is cylindrical, elongated, and unsegmented which is tapered at both ends. ● Body is covered with flexible, non-living cuticle while motile cilia and flagella are absent.

Parasitic Nematode (ES)

The anterior tip of both sexes is less pointed than the posterior. ● Within each lateral line running down both sides of the worm is an excretory canal. ● The anus is found at the ventral, posterior end.

Parasitic Nematode (IS) - F

Reproductive tract is Y-shaped ● Ovaries - smallest diameter highly coiled tubules at the free end of the “Y” ● Oviduct - region where the tubule diameter is intermediate

Parasitic Nematode (IS) - F

Uterus - the largest diameter tubules ● Vagina - formed by the union of the two uteri ● Genital pore - located internally where the vagina attaches to the body wall

Anterior end of Ascaris

three lips that surround a triangular mouth

Parasitic Nematode (IS) - M

Reproductive tract is a single continuous tube. ● It ends at the posterior tip where it unites with the digestive tract to fom a cloaca (an opening common to digestive and reproductive tracts)

Parasitic Nematode (IS) - M

Testis - rounded mass region at the smaller, free end of the tubule; sperms are produced ● Vas deferens - intermediatediameter tubules where sperms pass; they arise from the testes

Seminal vesicle - where sperms are stored; continuous from the vas deferens ● Ejaculatory duct - region of the tubule near the cloaca; propels the sperm in the female vagina during copulation