Ch. 11&12 Lecture Assignment

Perhaps half of the U.S. population is infected with this organism that normally resides in tissue cysts containing bradyozoites; embryos of pregnant women are also at risk.

Toxoplasma gondii

Haploid cells that are unequal in size, such as sperm and egg, are called

anisogametes.

Cells that move about in the mesohyl, digest particles, and may specialize for other functions are the

archaeocytes.

Placozoans

are flat, plate-like animals with no symmetry.

The demosponges

are mostly marine but include freshwater sponges

The strange case of organisms that undergo meiosis to produce gametes that fuse to form a zygote internally without leaving the organism is a process called

autogamy

A sponge feeds by

beating the flagella of collar cells to form a current; food is absorbed by collar cells

Protozoans in the genus Trypanosoma cause

African sleeping sickness and Chagas disease.

What are long, thin pseudopodia supported by axial rods of microtubules called?

-not actinopodia

Which protozoan group has a complicated parasitic life cycle that nearly always involves the production of infective spores?

-not ciliates -i think it is sarcodines

Protective cysts are triggered by

-not food shortages

Which of the following is NOT a "ciliate?"

-stentor -Vorticella -Paramecium -Trichodina ALL CHOICES

Nutrition in unicellular eukaryotes is best described as

All are correct

Reproduction in at least some sponges is

All of the choices are correct

The various species of Plasmodium vary in

All of the choices are variables in Plasmodium.

Which of the following statements about sponges is NOT correct?

Ameboid cells capture food particles from the water

Which unicellular eukaryote is NOT correctly linked to the type of movement structure it possesses?

Apicomplexa-reticulopodia

The simplest of canal systems is found in the

Asconoids

Most of the time, although they usually have other options, protozoans reproduce by

Asexual cell division

Which structure is NOT correctly linked to the type of movement or podial function?

Axoneme-actin-binding protein that keeps ectoplasm from gelling

Which is NOT a correct description of a member of a protozoan group?

Development involves an embryonic stage

What happens during conjugation in most ciliates?

Haploid micronuclei are exchanged.

Which describes the mode of action of the causative agent of amebic dysentery?

It invades the intestinal lining and secretes enzymes that cause loss of fluid; it can also cause abscesses on the liver and other organs.

Which is an example of a Ciliophoran protozoa?

Paramecium

The ciliate group of protists would include

Paramecium caudatum.

Which of the following is/are correct descriptions of unicellular eukaryote characteristics?

No germ layers are ever formed.

Which one of the following statements regarding metazoan origins is true?

Placozoans may be similar to the single ancestral state. Features like their small nuclear genome and their large mitochondrial genome are features that may be derived from a common ancestor shared with some animal outgroups.

How does the mosquito transmit malaria from an ill person to a healthy person?

Plasmodium gametocytes are taken up from one person's blood, fuse to form a zygote that becomes a motile ookinete, that crosses the stomach wall, forms an oocyst that undergoes sporogony and the sporozoites then migrate to the saliva ducts to be injected into the human host.

Which is a member of the apicomplexan group of protists?

Plasmodium vivax

To what extent are the cells of a colonial Volvox specialized?

Somatic cells function in nutrition and locomotion while a few "germ" cells carry out reproduction.

Which of the following is NOT found in at least some sponges?

Spicules of fibrous protein

Which of the following statements about sponges is NOT correct?

Sponge cells can transform from one cell type to another, a trait not seen in other kinds of animals

Flagellated canals of syconoid sponges form by evagination of the body wall and these sponges often develop through a simple vase-like stage. Which of the following is a logical hypothesis based on this evidence?

Syconoid sponges were derived from asconoid ancestors.

Which one of the following statements regarding the origin of metazoans has the most support?

The choanoflagellates share features with the sponges, like having collars of microvilli surrounding a flagellum and being colonial. These shared features suggest a link to at least one metazoan lineage.

What are the functions of the macronucleus and one or more small micronuclei in Paramecium?

The micronucleus undergoes meiosis to produce haploid micronuclei that are exchanged in conjugation; the macronucleus is responsible for the "day-to-day" functions of the cell.

Some organisms undergo meiosis to produce gametes that fuse to form a zygote internally without leaving the organism. What is the effect of this process on genetic diversity of the offspring?

The offspring would vary from the parent because it would produce different recombinations of each chromosome pair.

Which statement about adult sponges is false?

Their bodies are aggregations of one cell type.

A Paramecium "knows" when it has encountered a noxious substance and backs off to veer away. As a one-celled organism, how does it "know" to do this?

This is a rather simple stimulus that changes the electrical potential difference across the cell membrane and depolarization of the membrane results in cilia reversing their direction of beating.

Which is NOT a trait of sponges?

Water enters through the osculum

What is found at the base of every flagellum or cilium?

a kinetosome

The most likely mechanism for removing excess water by contractile vacuoles is

a proton pump that also pulls water into the vacuole.

The macronucleus of a ciliate elongates, constricts and divides without going through the mitotic stages in a process called

amitosis

The early development of a globular colony (with flagella inward) that then turns inside-out (with flagella outward) is

called inversion, and it is very rare among animals, only occurring in colonial flagellates and sponges.

Cells responsible for water flow and capture of some particles are the

choanocytes.

Which protozoan is used to test hypotheses of how multicellular organisms arose from their closest unicellular relatives?

choanoflagellates

The structural protein found in all sponges is

collagen

Ectoplasm

contrasts with endoplasm; both ectoplasm and endoplasm are cytoplasmic components.

What is the specific structure in ciliates that serves as the site of expulsion for wastes called?

cytoproct

"Red tides" are caused by massive blooms of

dinoflagellates.

The chills and fever of malaria are correlated with

escape of populations of merozoites from red blood cells.

A protozoan with both plant-like photosynthesis and animal-like motility is most likely a

euglenoid.

Chalky fossils that formed the White Cliffs of Dover were produced by

foraminiferans.

Placozoans feed by

gliding over their food, secreting enzymes, and absorbing products.

The protozoan dictyosome is called what in other eukaryotes?

golgi apparatus

The most correct usage of the term "protozoa" is as a(n)

informal cluster of groups with complicated and uncertain phyletic relationships.

The most complex and the most common body form of sponges is found in the

leuconoids.

Specialized archaeocytes that secrete large quantities of collagen are

lophocytes.

The largest impact that the loss of sponges would have on the environment would be

loss of filtration.

The extracellular matrix found in sponges is

mesohyl or mesenchyme

Mosquitoes that transmit malaria pick up what stage(s) when feeding on the blood of a patient ill with malaria?

microgametocytes and macrogametocytes that mature into gametes in the insect host

Which organelle was once an independent aerobic prokaryote engulfed by an anaerobic prokaryote?

mitochondrion

The modified cells of sponges that form circular bands and provide just a little constriction to control water flow are

myocytes.

Concerning producing larger organisms without cellular differentiation,

nature has evolved larger unicellular organisms but they are rare and have surface-to-volume limitations.

Which of the following represents the arrangement of microtubules in axonemes of cilia?

nine peripheral pairs of microtubules plus one central pair

The order in which a drop of ink would pass by the structures in an ascon sponge is

ostia-spongocoel-osculum.

Members of Euglena have starch-like food storage material in the form of

paramylon bodies.

In most sponges, the free-swimming larva produced by sexual reproduction is called a(n)

parenchymula

The outer thin, flat, epithelial-like cells that cover the outside and some inside surfaces of sponges, are

pinacocytes.

Most ciliophoran protozoa

possess a cytostome.

If a sponge is fragmented and cells are dissociated from one another, the cells will

reorganize their structure and function, and clumps of isolated cells will form a new sponge.

Specialized archaeocytes that secrete spicules are

sclerocytes

Calcareous or siliceous elements of the sponge body wall provide support. These elements are called

spicules

Specialized archaeocytes that secrete spongin are

spongocytes

The sponges date back to

the Cambrian period and probably earlier.

In glass sponges, archaeocytes fuse their pseudopodia to form a

trabecular reticulum.

Chagas disease in the Americas is carried by

triatomine "kissing" bugs.

The unique feature of sponge development in members of the class Calcarea is the amphiblastula which

turns inside out during its development.

When a nucleus has chromatin that is clumped, leaving clear areas within the nucleus, the appearance is described as

vesicular

The strange case of organisms that undergo meiosis after fertilization and live out their adult life in the haploid state is a case of

zygotic meiosis.