Unit 9 ~ Learning Guide Name: - BC Learning...

BCLN BIOLOGY 11 – Rev July 2014

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Unit 9 ~ Learning Guide Name: _______________ INSTRUCTIONS Complete the following notes and questions as you work through the related lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions about anything that you don't understand BEFORE you write the unit test. 9.1 NOTES: CHARACTERISTICS OF ANIMALS There are approximately _____________________________ recognized by zoologists. We are going to spend the remainder of the course looking at the most common animal phyla. We will start with the simplest phyla and work our way to the most complex. Below is a list of animals you will learn more about. Phyla Studied in Biology 11

Porifera Cnidaria Platyhelminthes Nematoda Annelida

_____________ Sea anemone ______________ Ascaris Earthworms

10 000 known species coral flukes Leeches

Calcareous, glass, coralline, demosponges

_____________ _____________ _____________

______________


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Phyla Studied in Biology 11 Continued

Mollusca Arthropoda Echinoderms Chorodata Vertebrates

clams, oysters, mussels spiders sea urchin

snails, nudibranchs crab, lobster sand dollar

chitons insects sea star

squid, octopus sea cucumber

How did animals evolve? Today it is thought that... The earliest animal probably _______________________ _______________________ _______________________ ______________ (700 mya) Hypothesis: _____________ _______________________ _______________________ and the early animals populated seas, fresh waters, and eventually land. Use the following table to make comparisons between phyla as you move through the rest of the course.


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Characteristics of Animals Animals are ____________________________________________ ______________________________________________________ ______________. Animals can be large, have a stable controlled internal environment and __________________________. Animals have two unique types of tissues: __________________________ ______________ for impulse conduction and _________________ ______________for movement (tissue: several cells working together to do a job; organ: made up of several different tissues). As we go through this part of the course look for development of sensory organs and coordination of systems.

What does it mean to be multicellular?

• ___________________________________________________ • usually have different cell types • ________________________________________________________________

_____________________________________ that benefits the whole animal • cells work together by forming tissues ______________________________

________________________________________________________________ • __________________________________________________________ (group

of different types of cells working together to perform a common function - ex. heart is formed of muscle and nerve tissue working together).

• Having many cells allows ___________________________________________ ___________________________________________________. Because of cell specialization the animal can be large. They can also move. This size allow


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stabilization of the animal's internal environment and relative independence from a harsh environment.

What does it mean to be heterotrophic? Heterotrophs must ingest other organisms or organic material that is decomposing. Heterotrophic organisms obtain organic molecules by consuming other living things. This is the opposite of autotrophic organisms that make their own organic molecule.


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Animal Development _____________________________________________________________________________________________________________ In most species, small flagellated sperm fertilizes larger non-motile eggs. The zygote goes through mitotic cell divisions and _________________________________________________________________ ________________________________________. During gastrulation, ____________________________________________________ ______________________ (a small dent). ________________________________ ______________________________. The __________________ as the inner layer and the _______________________ as the outer layer. After gastrulation there are two patterns of development:

1. __________________________ - the blastopore develops into the. ___________

2. __________________________ - the blastopore develops into the ___________


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Classifying Animals Animals, being such a diverse kingdom, are classified into phyla based on a variety of characteristics. Those characteristics include:

1. ___________________________________________ 2. _______________________________________________________________ 3. ___________________________________________ 4. ___________________________________________

***THIS IS VERY IMPORTANT: AS YOU LEARN ABOUT THE VARIOUS PHYLA YOU WILL BE ASKED TO COMPARE THEM BASED ON THE

ABOVE CHARACTERISTICS. *** Levels of Organization, Body Cavity, and Body Plan Levels of organization from simplest to most complex is ____________________________________________________________________. Although many animals have the highest level of organization, ______________________________________, some are only organized at the _____________________________. This means that _____________ ____________________________________________. Those that do have tissues can be distinguished from those with organs ____________________________________________________________________. If an animal develops with________________________________________________ ___________________________________________________. If an organism has __________________________________________________________________________________________________________. _______________________________________________________. Not all animals have all ____________________________________________________. There are three possibilities given below:

1. __________________________________ ___________________- body plan is a blind sac or _________________________. With this type of body plan food goes in the same opening waste comes out of. Examples of acoelomates are Cnidarians (ex. Jellyfish) and Platyhelminthes (flatworms).


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2. _______________________________________________ ________________________________ - body plan is a __________________________________. A tube-within-a-tube has a separate digestive system (inside tube) surrounded by the body (outside tube). This allows for more specialization of tissues as different sections of the tube develop to perform different roles. _______________________________________________________________ _______________________________________________. An example of a pseudocoelomates are _____________________________________________.

3. ______________________________________ _________________________ or body cavity - body plan is a _____________________ __________, but ____________________ __________________________________ __________________. These organisms often have ____________________________________________________ _______________________________________________. Coelomates include __________________________________, Mollusca (mollusks), Echinodermata (ex. sea star).

YOU SHOULD COMPLETE THE ORGANIZATION PRACTICE

EXERCISES BEFORE PROCEEDING ANY FURTHER! Types of Symmetry and Segmentation Symmetry describes ___________________________________________________ _________________________. Animals can be asymmetrical, radially symmetrical, or bilaterally symmetrical. _________________________________________________________________. No matter how you slice it both sides will be of a different shape. These animals are often sessile or non-motile.


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___________________________________________________________________________________________________________________________________. These animals can be compared to round objects such as bowls, tires, or wheels. These animals are often, but not always sedentary. ______________________ ______________________ ______________________ ______________________ _____________________. They can only be cut one way to produce two equal halves. These animals are ________________________________________________ _________________________________________. The word cephalization comes from the root word cephalon which _____________________________. Although not all animals with cephalization have a distinct head, they will have_______________________________________________________________________________________. This nervous tissue is found only in animals. __________________________________________________________________________________________________________________________________________. The ____________________________________________ is referred to as segmentation. This _________________________________________________ _____________________________ as different segments can specialize for different roles.


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9.1 PRACTICE: CHARACTERISTICS OF ANIMALS

1. What are the earliest animals hypothesized to have evolved from? (1 mark)

2. What are 4 key characteristics of all animals? ( marks)

3. Define multicellular and explain how it may provide animals with a selective advantage. (3 marks)

4. Define heterotrophic. (1 mark)


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5. Compare and contrast development in animals that are protostomes and those that are deuterostome. Your answer should include the terms gastrulation, blastopore, mouth and anus. (3 marks)

6. Most animals have three germ layers that give rise to all other tissues. What are these three layers called? (3 marks)

7. Label each diagram below using the terms coelomate, pseudocoelomate, and acoelomate. (3 marks)

a. _____________ b. _____________ c. _____________


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8. Label each diagram below using the terms asymmetry, radial symmetry, and bilateral symmetry. (3 marks)

a. _____________ b. _____________ c. _____________

9.2 NOTES: PORIFERA

YOU SHOULD WATCH THE PORIFERA INTRODUCTION VIDEO BEFORE PROCEEDING ANY FURTHER!

Introduction to Phylum Porifera ¨…the subject is actually repulsive in its difficulties'' - Carter (1875) on the study of sponges

Phylum Porifera

The simplicity of this group led to the frustration of scientists such as Carter for many years. Being _______________________________ and _______________________________________________ _____________________________ are _____________________ _____________________________________________________. For these reasons they were often classified as plants. However, upon examination of their ________________________________ ______________________ was determined that ______________ _____________________________________.

The term______________________________________________________________.


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The ¨pore bearers¨ are the sponges and are thought to be one of the oldest multicellular species. Fossils of sponge spicules have been found in the pre-Cambrian era rock layers dating to 600 million years ago.

It is the sponges with a spongin skeleton that are dried and used commercially. The skeleton of these animals was used as a washing sponge before synthetic sponges became common. They can still sometimes be purchased as a ¨sea sponge¨ for sponge painting or you may find that the sponge that you have been bathing with is really an animal. Did you know that the bath sponge actually received its name from the animal and not the other way around?

There are about 9000 different species of Sponges. SIZE Sponges range in size from as small as 0.5 cm tall to as large as 2 meters tall. HABITAT mostly warm marine waters ____________________________________ __________________________________________ do exist. Example: Grantia BODY ORGANIZATION Sponges have _________________________________________________________ __________________ because they have no true mesoderm. ____________________ _________________________________________________________________________________________. In addition, they _________________________________ _____________________________________________________________________. Sponges have many pores on their surface that are both ________________________ _____________________________________________________________________.

These multicellular sponges ________________________________________.

1. Endoderm – inside skin. 2. Ectoderm – outside skin, protective.

The “middle area” contains ________________________________________________ ____________________________________________________.


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___________________________________________________________ in the middle layer ________________________________________________________________ (hence the name). _______________________________________________________ ______________________________________________________________________________________________________________. They also carry oxygen to other cells, dispose of waste products, and maintain the structure of the sponge. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ MOVEMENT The _____________________________________ (moving) and can swim. The __________________________________________ (non-moving). Adults are attached to substrate such as rocks.

. CLASSES OF SPONGES

• Demospongea o _________________________________________

• Hexactinellida o _________________________________________

_________________________________________

• Calcerea o _________________________________________

_________________________________________ Sponge Reefs were thought to be abundant during the Jurassic period 200 million years ago. These reefs were thought to be extinct until 4 reefs were found in the early 1990s. Sponge reefs are restricted to temperate Pacific coastal waters. Such reefs exist in Hecate Strait and Queen Charlotte Sound


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Feeding in Sponges

A sponge that is 10cm tall must filter more then 100L of water a day to stay alive!!

In feeding, _____________________________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________. The sponge is a _____________ ______________________ and ____________________________________________ _______________________________________. The food particles are then either digested by the collar cell or passed to an amoeboid-like cell for digestion and circulation.

YOU SHOULD WATCH THE PORIFERA FEEDING VIDEOS BEFORE PROCEEDING ANY FURTHER!

Review of Feeding in Porifera (Sponges)

• not a true digestive system • _______________________________ – food enters with water • water enters via tiny pores (ostia) = incurrent. • water exits via massive pore (osculum) = excurrent • collar cells (choanocytes) engulf and digest food

Reproduction in Sponges

Both _______________________________________________________ occur in sponges. ______________________________________________________________ __________________________________. In __________________________, a piece breaks off and forms a separate animal. In _________________________, the animal reproduces by growing a second sponge from the side of the parent that eventually detaches. During sexual reproduction, an egg and sperm combine to form a flagellated zygote which can swim to a new location.


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REPRODUCTIVE SYSTEM

• not a true reproductive system. • Again we see sperm and eggs are specialized cells • Sponges are monoecious meaning a single sponge can make both egg and

sperm.

RESPIRATORY SYSTEM

• not a true system • ____________________________________________________________ (O2

diffuses into and CO2 out of cells) • water enters via tiny pores (ostia) = incurrent • water exits via massive pore (osculum) = excurrent

CIRCULATORY SYSTEM

• not a true system • specialized cells = ___________________________ to other cells in the sponge.

EXCRETORY SYSTEM

• not a true system • specialized cells = ______________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________

• Water enter via ostia = incurrent. • Water exits via osculum = excurrent.

NERVOUS SYSTEM

• NONE MUSCULAR SYSTEM

• NONE


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SKELETAL SYSTEM

• NONE Economic Importance of Porifera

Sponges are used for____________________ (spicules of spongin). They have the ability to hold large amounts of water. Sponges have now been replaced with synthetic materials for cleaning. Natural sponges are still harvested from the Gulf of Mexico. _________________________ _____________________________________

9.2 PRACTICE: PORIFERA

1. Despite being simple animals, Porifera can be quite complex to understand as they tend to lack some of the characteristics often associated with animals.

a. What two characteristics do they lack that make Porifera an unusual animal? (2 marks)

b. What 2 main characteristics were observed to help classify Porifera as animals? (2 marks)


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2. While Porifera have specialized cells, they lack any sort of _________________ (group of similar cells working together to perform a common function) or true body plan. (1 mark)

3. Porifera have several specialized cell types including:

a. ________________________ which are mobile cells that help distribute nutrients throughout the sponge. (1 mark)

b. ________________________ which help provide structure and are used to help classify Porifera. (1 mark)

c. ________________________ (also known as choanocytes) which have

flagella and create currents to help in filter-feeding and waste removal. (1 mark)

4. The larvae stage of Porifera is ______________________ (moving) while the adult stage is ________________________ (non-moving). (2 marks)

5. Water enters the Porifera via its _____________________ and exits via its ____________________. (2 marks)

6. Identify and describe three different ways that Porifera can reproduce. (3 marks)

7. Porifera are said to be __________________________ as a single specimen is capable of producing both egg and sperm. (1 mark)

8. Porifera _______________ a true respiratory system, rather they simply

exchange gasses directly between their cells and the water via ___________________________. (2 marks)

9. Porifera _______________ a true circulatory system, rather they rely on

________________________ cells to distribute nutrients to their cells. (1 mark)


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10. Porifera _______________ a true excretory system, rather their cells ______________________ release waste into the water or they rely on ________________________ cells to help collect and remove waste. (3 marks)

11. Porifera do not have any form of a ____________________ system, ____________________ system or a _______________________ system. (3 marks)

12. Identify three characteristics of the Phylum Porifera that give them a selective advantage (i.e., characteristics that have helped them survive the 600 million plus years that they have inhabited the Earth). Explain how these characteristics may have helped their survival. (6 marks)


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9.3 NOTES: CNIDARIA Introduction to Cnidaria Phylum Cnidaria includes animals such as____________________________________ _____________________________________________________________________. Cnidae refers to the creatures’ _______________________________ and they are commonly called ¨sea nettles¨. Nettles are a stinging plant. Cnidarians are further up the “evolution ladder” meaning ______________________________________________________________(sponges) There is estimated to be approximately 10 000 species of Cnidarians. The habitat for most cnidarians is__________________________ (marine = salt water) but some species live in _________________________. ___________________________________________________ __________________________________________. The medusa form (bell-shaped) __________________ (moving) while the ___________________________________________ ________________ (non-moving). Some cnidarians exist in both forms throughout their life cycle showing an ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________


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The size of cnidarians ranges from as small as a 0.5 cm tall bell up to a 2.4 m diameter with tentacles ranging upwards of 50 meters. FACT: Cnidarians have a single external opening that serves as both the mouth and the anus! Characteristics of Cnidarians

Cnidarians are a _____________________________________ animal. They can be __________________________________ and some species will have life cycle stages of both polyp and medusa.

They have an _______________________________________________________ ______________________________________________________________________ ________________________________. These ____________________________ lead to a tissue level of organization. __________________________________ __________________________________________________________________. The gastrodermis surrounds the center of the body which is called the _____________________________________________________________________________________________________. That is, food enters the same opening that waste is excreted through. Tentacles are arranged to surround the mouth. ___________________________________________________________________________________________________________ are examples of polyps. The difference being that corals have a calcium carbonate skeleton while sea anemones _____________________________________________________________________ ____________________________________________________________________________________________________________________________________________


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Stinging Cells

For capturing prey and for defense _________________________________ _________________________________ _________________________________ _________________________________ _________________________________ which contains a coiled hollow thread. These nematocysts are triggered to discharge by direct contact or other external stimulus. The thread will uncoil when the cnidarian is touched and spear the prey or predator. The spines help anchor the stinging thread into the prey.

In some species these threads _____________________________________________ ____________________________________________. This is why handling jellyfish can cause the skin to numb or in more severe cases cause muscle paralysis and heart failure. In some areas of the globe large numbers of jellyfish cause beach closures. The sting of a Box jellyfish may cause death in as little as 3 to 20 minutes.

CLASSES OF CNIDARIA There are 4 classes of Cnidaria

• Class Hydrozoa o Example: _________________________________________

• Class Scyphozoa

o Example:_________________________________________

• Class Cubuzoa o Example:_________________________________________

• Class Anthozoa

o Example:_________________________________________


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Class Hydrozoa This class of cnidarian includes approximately 3,700 species. Most live in colonial organizations in the oceans. Example: Physalia - ______________________________ ________________________________________. Its gas filled float keeps the colony at the surface of ocean. Tentacles can be up to 20m long and the nematocysts poison can be fatal More on the Hydra As previously stated, ___________________________________________________ __________________________ in most lakes and ponds. _______________________ ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ During development the endoderm and ectoderm produce different tissues. ______________________________________ _________________________________________________________________________________________________________________________________________________________________________. Tentacles are used for prey capture and are controlled by muscle fibers and a ___________________________________________ ______________________________________________________________________ ___________________________________________________________________________________________________________________________________________


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Hydra _________________________________________________ by producing testis or ovaries in the body wall, but do not enter a life cycle with a medusa. Instead, the sperm and egg will combine and grow to form a polyp. _____________________________________________________________________ ______________________________________________________________________

YOU SHOULD COMPLETE THE LABEL THE HYDRA ACTIVITY BEFORE PROCEEDING ANY FURTHER!

Class Scyphozoa This class of Cnidarians are referred to as "cup" animals. This shape describes the ___________________ form. There are more than 200 species known commonly as jellyfish. They can have tentacles up to 7m long. ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________

• Life Cycle of a Jelly Fish To reproduce the _______________________ _____________________________________ _____________________________________ ___________________________. A zygote is formed followed by a blastula which leads to a planula (ciliated larva) and finally a new polyp.

Class Anthozoa The term Anthozoa means __________________________________. There are approximately 6,100 marine species.


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• Examples are: ____________________________________________________. ___________________________________________________. When they die their hardened skeletons remain and over time build up into ________________ _____________________. Coral reefs are restricted within 30 degrees north or south of the equator as they require sunlight. Corals get the majority of their food energy from photosynthetic algae.

Some sea anemones have a symbiotic relationship with clown fish Phylum Cnetophora There are approximately 100 species of Ctenophora. The term _____________________ refers to the _____________________________________________ ______________________________________________ that run along the outside. Unlike jelly fish ___________ _____________________________________________. They are the largest organism to move this way. Ctenophora resemble jellyfish and are called _________ ______________. Comb jellies have _______________________________________. They_________________________________________________________________ __________________________________________________. Colloblasts are normally located on 2 tentacles. They also _____________________________________________________________________ _____________________________________________________________________________________________________________. The most striking of these species are bio-luminescent so can produce light.

Cnidaria Body Systems DIGESTIVE SYSTEM

• not a true system.


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• Food enters __________________________________________ mouth. • ___________________________________ (enzymes secreted into cavity). • Cells lining the cavity absorb digested nutrient and smaller food particles. • The relationship between structure and function is clearly seen in the way

cnidarians feed. The tentacles capture small animals with their nematocysts and paralyze them by injecting poison. The tentacles then push the prey into their gastrovascular cavity through the mouth. Once in the mouth enzymes found here break up the prey and the cells lining the cavity absorb the nutrients.

CIRCULATORY SYSTEM

• not a true system. • nutrients and gasses _____________________ directly across the thin cell

layers RESPIRATORY SYSTEM

• not a true system. • Gas exchange directly between cells and water by __________________ (O2

diffuses into and CO2 out of cells) both across epidermis and gastrovascular tissues.

EXCRETORY SYSTEM

• not a true system. • Waste diffuses from cells into gastrovascular cavity and is then released through

the mouth. MUSCULAR SYSTEM

• NONE. • No muscle cells but some cells can contract and relax (e.g. in the tentacles).

SKELETAL SYSTEM

• NONE NERVOUS SYSTEM

• a basic system. • A ______________________________________ that react to presence of food

and danger for the purposes of feeding and protection. REPRODUCTIVE SYSTEM

• Many cnidarians alternate between _______________________________ ________________ forms in their life cycle. _____________________________


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• _______________________________________________________________. 9.3 PRACTICE: CNIDARIA

1. Phylum Cnidaria derives its name from cnidae which refers to this phylum's characteristic ____________________ cells. (1mark)

2. Correctly label each diagram below using the terms polyp, medusa, sessile and motile. (4 marks)

a. _____________________ c. _____________________ b. _____________________ d. _____________________

3. Cnidaria have ____________________________ symmetry. (1 mark)

4. Cnidaria have ______ germ layers and specialized cells that form true _________________________. (2 marks)

5. The stinging cell of a Cnidaria is called a ____________________ which

contains a special capsule called a ________________________ which can be discharged in response to stimuli. (2 marks)

6. The Hydrozoan class of Cnidaria include Hydra's whose adult form is a sessile

_____________________. The hydra is capable of reproducing both ______________________ and _________________________. (3 marks)


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7. Label the diagram below with the following terms. Please provide a brief explanation the function of each structure. Please be neat. (12 marks)

o nerve net o gastrovascular cavity o mesoglea

o gastrodermis o tentacles o epidermis


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8. Jelly fish belong to Phylum __________________, Class ___________________. (2 marks)

9. ____________________ and corals belong to the Phylum

__________________, Class ____________________ which means ____________________________. (4 marks)

10. Comb jellies belong to the Phylum _______________, Class _________________ and move through the water by beating their _________________________. (3 marks)

11. While Cnidarians lack a true digestive system they do have a single opening that serves as both ______________ and ________________ for entry of food and exit of waste. As well their _____________________________________ allows for extracellular digestion of food followed by its absorption into cells across the _________________________________. (4 marks)

12. Cnidarians also lack a true circulatory system which is not required as nutrients can simply ______________________ directly across their thin cell layers via the gastrodermis. (1 mark)

13. Cnidarians also lack a true respiratory system which is not required as gasses can simply ______________________ directly across their thin cell layers via the gastrodermis and epidermis. (1 mark)

14. Cnidarians also lack a true excretory system which is not required as wastes

diffuse directly across the gastrodermis into the __________________________________________________ before exiting the "mouth". (1 mark)

15. While Cnidarians lack a muscular system they do have some cells that are able to _______________________ and ______________________ within their tentacles. (2 marks)

16. Cnidarians have a basic nervous system that includes a ___________________ _____________________________ that allow them to react to the presence of food and danger. (1 mark)


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17. Many Cnidarians are capable of reproducing both ______________________

and _________________________. (2 marks)

18. Phylum Cnidaria are considered "further up the evolutionary ladder" than Phylum Porifera in that Cnidarians are more complex.

a. Identify three "evolutionary advances" that Cnidarians have compared to Porifera and explain how these "advances" may help the Cnidarians to survive (i.e., provide a selective advantage). (6 marks)


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b. Although Cnidarians may be considered more complex, Porifera have survived on the Earth longer suggesting that they are well adapted to survive in their habitat. Identify one characteristic unique to Porifera compared to Cnidarians that may help them to survive and explain how it may do so. (2 marks)

~ END OF BIOLOGY 11 UNIT 9 LEARNING GUIDE ~


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UNIT 9 ANSWER KEY 9.1 PRACTICE: CHARACTERISTICS OF ANIMALS

1. What are the earliest animals hypothesized to have evolved from? (1 mark)

- from a flagellated, colonial protist about 700 million years ago

2. What are 4 key characteristics of all animals? ( marks)

- multicellular (with most animals being made up of a variety of specialized cells) - eukaryotic cells that contain membrane-bound organelles but lack a cell wall - motile = can move at some point during life cycle - heterotrophic = cannot produce own organic compounds from solar energy, must

eat other living (or once-living) organisms

3. Define multicellular and explain how it may provide animals with a selective advantage. (3 marks)

- being composed of multiple cells that work together to make a functional whole - advantage = various cells can specialize and thus, be very efficient at a

particular task while relying on other cells to perform tasks that they are less efficient at

4. Define heterotrophic. (1 mark)

- must consume other living or once-living organisms to obtain organic molecules and energy (aka consumers)

5. Compare and contrast development in animals that are protostomes and those that are deuterostome. Your answer should include the terms gastrulation, blastopore, mouth and anus. (3 marks)

- both protostomes and deuterostomes form a complete digestive tract that by definition has two openings…a mouth and an anus

- protostome = blastopore will develop into mouth - deuterostome = blastopore will develop into anus


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6. Most animals have three germ layers that give rise to all other tissues. What are these three layers called? (3 marks)

- ectoderm (outer layer), mesoderm (middle layer) and endoderm (inner layer)

7. Label each diagram below using the terms coelomate, pseudocoelomate, and acoelomate. (3 marks)

a. _____________ b. _____________ c. _____________

8. Label each diagram below using the terms asymmetry, radial symmetry, and bilateral symmetry. (3 marks)

a. _____________ b. _____________ c. _____________


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9.2 PRACTICE: PORIFERA

1. Despite being simple animals, Porifera can be quite complex to understand as they tend to lack some of the characteristics often associated with animals.

a. What two characteristics do they lack that make Porifera an unusual animal? (2 marks) - sessile - lack true tissues

b. What 2 main characteristics were observed to help classify Porifera as animals? (2

marks) - feeding habits (heterotrophic) - pattern of embryo development

2. While Porifera have specialized cells, they lack any sort of _________________ (group of similar cells working together to perform a common function) or true body plan. (1 mark)

3. Porifera have several specialized cell types including:

a. ________________________ which are mobile cells that help distribute nutrients throughout the sponge. (1 mark)

b. ________________________ which help provide structure and are used to help classify Porifera. (1 mark)

c. ________________________ (also known as choanocytes) which have flagella and

create currents to help in filter-feeding and waste removal. (1 mark)

4. The larvae stage of Porifera is ______________________ (moving) while the adult stage is ________________________ (non-moving). (2 marks)

5. Water enters the Porifera via its _____________________ and exits via its ____________________. (2 marks)

6. Identify and describe three different ways that Porifera can reproduce. (3 marks)

- asexual…budding - asexual…fragmentation - sexual

7. Porifera are said to be __________________________ as a single specimen is capable of

producing both egg and sperm. (1 mark)

8. Porifera _______________ a true respiratory system, rather they simply exchange gasses directly between their cells and the water via ___________________________. (2 marks)


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9. Porifera _______________ a true circulatory system, rather they rely on ________________________ cells to distribute nutrients to their cells. (1 mark)

10. Porifera _______________ a true excretory system, rather their cells ______________________ release waste into the water or they rely on ________________________ cells to help collect and remove waste. (3 marks)

11. Porifera do not have any form of a ____________________ system, ____________________ system or a _______________________ system. (3 marks)

12. Identify three characteristics of the Phylum Porifera that give them a selective advantage (i.e., characteristics that have helped them survive the 600 million plus years that they have inhabited the Earth). Explain how these characteristics may have helped their survival. (6 marks)

- answers may vary but may include: o being able to reproduce in multiple ways…sexually provides greater

diversity and therefore greater chance of surviving natural selection as a species whereas asexually provides opportunities to continue species even when populations/mate availability is scarce

o spicules help to provide protection against predators as they are rough and difficult to digest

o even though Porifera lack true tissues they are multicellular with specialized cells that work together to increase efficiency of life processes and thus, increase the chance of survival

9.3 PRACTICE: CNIDARIA

19. Phylum Cnidaria derives its name from cnidae which refers to this phylum's characteristic ____________________ cells. (1mark)

20. Correctly label each diagram below using the terms polyp, medusa, sessile and motile. (4 marks)

a. _____________________ c. _____________________ b. _____________________ d. _____________________


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21. Cnidaria have ____________________________ symmetry. (1 mark)

22. Cnidaria have ______ germ layers and specialized cells that form true _________________________. (2 marks)

23. The stinging cell of a Cnidaria is called a ____________________ which contains a special

capsule called a ________________________ which can be discharged in response to stimuli. (2 marks)

24. The Hydrozoan class of Cnidaria include Hydra's whose adult form is a sessile

_____________________. The hydra is capable of reproducing both ______________________ and _________________________. (3 marks)

25. Label the diagram below with the following terms. Please provide a brief explanation the function of each structure. Please be neat. (12 marks)

o nerve net o gastrovascular cavity o mesoglea

o gastrodermis o tentacles o epidermis

Nerve net…detect and

respond to environment

gastrovascular cavity…site of extracellular digestion of food

mesoglea…jelly-like layer that helps support hydra

gastrodermis…site of gas, nutrient and waste exchange

tentacles…sting for protection and capture food

epidermis…protective outer layer capable of gas exchange


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26. Jelly fish belong to Phylum __________________, Class ___________________. (2 marks)

27. ____________________ and corals belong to the Phylum __________________, Class

____________________ which means ____________________________. (4 marks)

28. Comb jellies belong to the Phylum _______________, Class _________________ and move through the water by beating their _________________________. (3 marks)

29. While Cnidarians lack a true digestive system they do have a single opening that serves as both ______________ and ________________ for entry of food and exit of waste. As well their _____________________________________ allows for extracellular digestion of food followed by its absorption into cells across the _________________________________. (4 marks)

30. Cnidarians also lack a true circulatory system which is not required as nutrients can simply ______________________ directly across their thin cell layers via the gastrodermis. (1 mark)

31. Cnidarians also lack a true respiratory system which is not required as gasses can simply ______________________ directly across their thin cell layers via the gastrodermis and epidermis. (1 mark)

32. Cnidarians also lack a true excretory system which is not required as wastes diffuse directly

across the gastrodermis into the __________________________________________________ before exiting the "mouth". (1 mark)

33. While Cnidarians lack a muscular system they do have some cells that are able to _______________________ and ______________________ within their tentacles. (2 marks)

34. Cnidarians have a basic nervous system that includes a ___________________ _____________________________ that allow them to react to the presence of food and danger. (1 mark)

35. Many Cnidarians are capable of reproducing both ______________________ and _________________________. (2 marks)

36. Phylum Cnidaria are considered "further up the evolutionary ladder" than Phylum Porifera in that Cnidarians are more complex.

a. Identify three "evolutionary advances" that Cnidarians have compared to Porifera and explain how these "advances" may help the Cnidarians to survive (i.e., provide a selective advantage). (6 marks)

- Answers may vary but may include:

o Nerve net that enables cnidarian to detectand respond to environment including sensing and responding to the presence of food or danger…being able to feed and protect oneself = greater chance of survival


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o Presence of stinging cells to neutralize food and to harm predator = greater chance of survival

o Gastrovascular cavity allows for efficient extracellular digestion of food before uptake into cells as compared to the continual flow of food particles through the central cavity…more efficient nutrient uptake = greater chance of survival

o Motility allows species to disperse which can increase survival by decreasing competition amongst individuals and increasing the various environments that the species are exposed such that it may find a better "fit" with respect to natural selection

b. Although Cnidarians may be considered more complex, Porifera have survived on the Earth longer suggesting that they are well adapted to survive in their habitat. Identify one characteristic unique to Porifera compared to Cnidarians that may help them to survive and explain how it may do so. (2 marks) - Answers may vary but may include:

o Porifera have three methods of reproduction (budding, fragmentation and sexual) whereas cnidarian have two methods of reproduction (budding and sexual)…the ability to reproduce by fragmentation means that if a part of the Porifera is accidently broken off or disturbed, the Porifera is not necessarily destroyed but rather both fragments may grow and thus, increase the Porifera population

o the ability to filter feed enables the Porifera to actively draw hundreds of liters of water with potential food towards itself compared to the polyp forms of Cnidaria which must passively rely on food to enter its space before it can capture it

o regardless, each phylum has, through random mutation and natural selection, evolved adaptations that enable them to best survive in a particular niche or niches within their environments

Unit 9 ~ Learning Guide Name: - BC Learning...

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