Unit 5: Animal Invertebrates Bio A

What is the smallest unit of life?

cell/The smallest unit of matter is the atom. Everything in the universe, both living and non-living, is made of atoms. Only living things are made of cells. The cell is smallest unit of life.

What are tissues?

groups of specialized cells with a common function found in most animals/Tissue is a common feature among most animals. It is composed of many cells that act together for a common function.

Which of the following is true concerning animals?

With the exception of gametes, all animal cells are diploid/All animals are multi-cellular. Anything that is animal-like but uni-cellular is considered a protist, not an animal. All animal cells lack a cell wall. All animals reproduce sexually. Animal cells are diploid, but gametes (eggs and sperm) are haploid.

What is a common feature of animals?

develop from a blastula/All animals lack a cell wall, are made of diploid cells, form blastulas, and reproduce sexually.

Which of the following embryonic layer gives rise to muscle and bone?

mesoderm/Animals have three primary tissue types (ectoderm, endoderm, and mesoderm) in a developing embryo. Each gives rise to certain organs. Ectoderm gives rise to skin and eyes. Endoderm gives rise to the lining of the digestive tract and the liver. Mesoderm gives rise to muscle and bone.

What type of cells are egg and sperm? And how does egg size compare to sperm size?

They are both haploid gametes, and egg cells are bigger than sperm cells./Both eggs and sperm are gametes. These sex cells only have one set of chromosomes, which makes them haploid, as opposed to diploid cells, which have two sets of chromosomes. Sperm and egg cells combine to create a diploid cell. Egg cells are much larger than sperm cells.

If an animal body is asymmetrical, what would it look like?

The body would have an irregular shape without any type of symmetry/Asymmetrical bodies are irregularly formed without a definite shape.  An asymmetrical body is without symmetry.

Which phrase describes bilateral symmetry?

A type of symmetry in which a single line can be drawn down the center of the body from the top of the head all the way to the tail and on each side of the line are two pieces that are mirror images to each other

Which phrase describes radial symmetry?

Radial symmetry can be visualized using a bike wheel or a pizza.  Body plans that are radial have body parts arranged around a central axis and each part is equal to every other part around the axis/

What does cephalization mean and what type of body symmetry lend itself to it?

It is the concentration of nervous tissue on the anterior end of an animal with bilateral symmetry./In other words, it is the formation of a head and brain in those animals that are bilaterally symmetrical.

What types of organisms are bilaterally symmetrical? 

• dolphins

• sponges

• jellyfish

• sea anemones

dolphins/Dolphins are the only organism listed that could be considered to be bilateral.  You can draw a central line down the body of a dolphin to create two mirror images on either side.  Sponges are asymmetrical.  Jellyfish and sea anemones have radial symmetry.

What types of organisms are radially symmetrical?

• sponges

•  corals, sea anemones, and jellyfish

• elephants, sharks, and chimpanzees

•  fish, worms, and frogs

corals, sea anemones, and jellyfish/Sponges are asymmetrical.  Elephants, sharks, chimpanzees, fish, worms, and frogs are all bilaterally symmetrical.  Corals, sea anemones, and jellyfish are radially symmetrical.

What do phylum Porifera (sponges) and phylum Placozoa have in common?

Both contain animals with asymmetrical body plans/

Which of the following phyla contains a majority of animals that eat by means of phagocytosis?

Placozoa

Which of the following cells within Trichoplax adhaerens is most involved in digestion?

gland cells

Which of the following cells within Trichoplax adhaerens are thought to play a major role in the animal's movement?

Fiber cells/Fiber cells play a major role in allowing the animal to change its body shape, thus aiding it in gliding along surfaces. 

Which of the following animals belongs in the phylum Placozoa?

Trichoplax adhaerens/ T. adhaerens is the only known animal to be classified in phylum Placozoa.

Where are the fiber cells located within Trichoplax adhaerens?

in between the endoderm and ectoderm layers/The fiber cells make up the meshwork in the middle of the animal, situated between the dorsal and ventral sides, or in between the ectoderm and endoderm layers.

What is the mesohyl of sponges?

It is the gel-like substance that delivers nutrients/Mesohyl is the gel-like substance all sponge cells are suspended within.

Which of the following is a flagellated cell that helps bring water and food into sponge pores?

choanocyte/Choanocytes are the flagellated cells that draw in water in through the ostia.

Which of the following is the silica or calcium carbonate needle that makes up some sponges' skeleton?

spicule/Spicules are tiny needles made up of silica or calcium carbonate.

What sponge cell is found in the mesohyl that helps bring nutrients to other cells and takes away cellular waste?

amoebocyte/Amoebocytes can move within the mesophyl, delivering nutrients and removing waste.

What is the large opening in a sponge that waste exit?

osculum/Waste exit the sponge via the osculum.

How does sexual reproduction occur in sponges?

A sponge releases sperm, which then enter another sponge via its ostia. The choanocytes deliver the sperm to the eggs, located within the mesohyl, where fertilization then occurs./Sponges release sperm and egg into the water where fertilization occurs. The fertilized egg grows into a larva, which swims around for a small time then plants itself in place where it grows into an adult sponge. Budding, shedding, and gemmule formation are modes of asexual reproduction in sponges.

Which of the following is a body form that is tube-like and attached to a firm surface with tentacles on the opposite side of the attachment?

polyp/Polyps are tube-like with tentacles on top the bodies, opposite the side of the attached base.

Which of the following is a body form that is shaped like an umbrella that is capable of swimming and has tentacles hanging below it?

medusa/Jellyfish are examples of medusas.  They are an inverted cup or umbrella with tentacles hanging below the umbrella.

Which of the following describes the anthozoan class?

A class that includes sea anemones and corals in which all the animals are in the polyp form.

Which of the following describes the scyphozoans?

They live in both body forms but mainly in the medusa form./Scyphozoans are all the true jellyfish, which start out as little polyps then grow up into medusas.

Which of the following describes a cnidocyte?

a stinging cell that contains nematocysts and is a distinguishing feature of all cnidarians

Which of the following animals has a gastrovascular cavity?

All corals, sea anemones, and jellyfish have a gastrovascular cavity.  Placozoans and poriferans do not

What kind of environments do rotifers inhabit?

aquatic areas/Rotifers are aquatic organisms. The vast majority of species are found in aquatic environments such as ponds, lakes, rivers, and streams. A portion of rotifers may be found in the damp soils or as parasites to aquatic life.

What anatomic structure is the phylum's name derived from?

the corona/The name rotifer, loosely translated, means wheel bearer. Early observers believed the semicircular appendages near the rotifer's mouth resembled a wheel. That is why they are referred to as rotifers or wheel animals.

Where does the majority of digestion and absorption of the rotifer's food occur?

The majority of digestion and absorption happens in the rotifer's stomach.

Which of the following structures is the only portion of the rotifer that fossilizes? 

The only hard portion of the rotifer's body is the trophi. This area is the only part that is usually found in the fossil records.

Which of the following structures is responsible for guiding food particles into a rotifer's mouth?

The cilia located around the rotifer's mouth are responsible for moving food into the rotifer's mouth. 

Why do some rotifers reproduce primarily through asexual reproduction?

male rotifers are extremely rare/ Females mostly rely on parthenogenesis for reproduction.

Which of the following mollusks are classified as Gastropods?

• snails

• oysters

• octopuses

• squids

snails/Gastropods include snails and slugs.  Octopuses and squids are cephalopods, and oysters are bivalves.

Which of the following is a mollusk larvae?

trochophore/All mollusk fertilized eggs eventually develop into a trochophore, a ciliated free-swimming larva.

Which of the following best describes the job of the nephridia in mollusks?

Nephridia release fluid waste from the coelom/The nephridia take up fluid waste from the coelom.  Nutrients are reabsorbed into the mollusk from the fluid in the nephridia.  The nephridia then releases the waste through an opening into the mantle cavity.

Which of the following describes the radula of mollusks?  

It is a tongue-like structure with backward curving teeth located in the mouth/On its surface are backward curved teeth that help scrape food off of rocks.

Which best describes the siphon in mollusks?

It is a structure that water shoots out of to propel the mollusk, and it releases dark liquid in some squids and octopuses.It assists the mollusk in moving away from danger quickly

Which of the following classes belongs to phylum Mollusca?

Cephalopoda/The three most common classes of phylum Mollusca are Cephalopoda, Gastropoda, and Bivalvia.  Hexactinellida is a class of sponges belonging to phylum Porifera.  Scyphozoa and Hydrozoa are both classes in phylum Cnidaria.

Which of the following is paired correctly?

1. phylum Porifera - flatworms

2. phylum Nematoda - sponges

3. phylum Platyhelminthes - roundworms

4. phylum Annelida - segmented worms

Phylum Annelida contains the segmented worms/and phylum Porifera contains sponges, phylum Nematoda contains round worms, and phylum Platyhelminthes contains flatworms.

What are the bristles found on Annelids called?

setae/The setae are the bristles found on Annelids, or segmented worms, that help them grip and move through the soil.

Which of the following phyla include flatworms and roundworms, respectively?

Phylum Platyhelminthes includes the flatworms and phylum Nematoda includes roundworms. Annelida includes segmented worms and Porifera includes sponges.

Which of the following is true regarding the worm phyla?

Annelida, Platyhelminthes, and Nematoda include animals with bilateral body plans./All worms--annelids, flatworms, and nematodes--have bilateral body plans. Annelids are the only worms with a coelom. Flatworms and nematodes are made up mostly of parasites. All worms are terrestrial, freshwater, or marine animals.

Which of the following are features that help group annelids into their particular classes?

Annelids are segmented worms and are classified into three classes--Polychaeta, Oligochaeta, and Hirudinea--depending on the presence of setae and parapodia. Polychaetes have both setae and parapodia, Oligochaetes have setae only, and Hirudineates have neither setae nor parapodia.

Which of the following is true of worms?

Annelids include the earthworms that benefit soil by aerating and fertilizing it. Flatworms and nematodes include many intestinal parasites./Annelids include the segmented worms, like the earthworm, that enrich soil by eating their entire weight in soil daily, creating tunnels that aerate the soil. The earthworms also fertilize the soil with their nutrient-rich feces. Flatworms and nematodes include many parasites, including intestinal parasites. Annelids are highly complex with a coelom and many organ systems. Flatworms and nematodes are simple worms that lack a coelom and highly developed organ systems.

Echinoderms get their characteristic spiny skin from the layering of which structure?

an ossicle/This structure is a skeletal unit.

The water vascular system is responsible for which function?

moving/The water vascular system controls the tube feet.

What advantage does mutable collagenous tissue give Echinoderms?

saves energy/Echinoderms use mutable collagenous tissue to lock into a position.

Although Echinoderms are invertebrates, which structure do they use for protection?

an endoskeleton/This structure is made up mostly of calcium.

How are dead Echinoderms naturally recycled?

They are the main ingredient in limestone/"Naturally" means that no human action is necessary to recycle dead echinoderms.

Which kind of symmetry is shown by Echinoderm larvae?

Bilateral/This kind of symmetry produces mirror images.

All Chordate embryos have a notochord, which in most animals develops into which structure?

vertebrae/Most chordates have a spinal column as adults.

In a closed circulatory system, what forces the blood to circulate through vessels?

the heart/This structure has either two, three, or four chambers.

Tunicates are classified as Urochordates because they lack which structure as adults?

vertebrae/Since tunicates are sessile, they don't need a backbone.

Members of subphylum Vertebrata have which protective brain structure?

cranium/The alternative name for subphylum Vertebrata is Craniata.

In humans, this embryonic structure develops into ear canals and the eustachian tubes.

pharyngeal slits/This embryonic structure gives rise to head structures in chordates.

Lancelets are placed in subphylum Cephlochordata because their backbone extends from their tail to where?

the head/Lancelets have a backbone found in the entire length of their body.