AP Biology Summer Assignment

Welcome to AP biology. Our class is intense, with a lot of material that needs to be covered in a relatively short amount of time. Please be aware that part of taking this class is commitment to being on time, on task, and occasionally learning content on your own. We look forward to working with each one of you next year! We know the words “summer assignment” tends to send chills down any high school student’s spine, but these assignments will be beneficial to you as we start the school year. The reason we are giving you a summer assignment is to keep your mind sharp so you are ready to hit the ground running! It is also important to realize that there is simply not enough time to cover the content of the course without a head start. Because AP Central has changed the Biology assessment we need to change the way we approach the summer assignment. Please adhere to the following criteria when completing your assignments.

It is important that you handwrite your work. This does not mean typing out your answers but instead handwriting your responses in the space provided on the following worksheets.

Work needs to be completed alone. You do not get to collaborate on the assessment so you should not be collaborating on these assignments.

Detail needs to be included in your answers. While we understand that you will need to use the internet to review content, we also expect that you will properly cite your sources and give credit to those individuals that aided in your understanding of the material.

The following worksheets and packets need to be completed no later than September 8th

1. Graphing and Data Skills Practice Packet

2. Cell Structure and Function Packet

3. Amazing Cells: Cell Communication Web Activity

4. Classification Worksheet

5. Classification and Taxonomy Packet

6. Creating Phylogenetic Trees from DNA Sequences: Student Worksheet

If these assignments are lost you are able to obtain another copy be visiting our school webpage at BWHS. Have a great summer and please contact us if you have any additional questions.

Mrs. Amber Poniatowski: Amber.Poniatowski@lcps.org Ms. Lauren Snow: Lauren.Snow@lcps.org

Name: _______________________________________________________ Date: _________ Block: _______

Graphing and Data skills practice Packet Math and Statistics for AP Biology - Research the answer to the following questions

1. In designing an experiment or other scientific study, why do scientists sample from a population

rather than using an entire population?

2. Suppose you are designing an experiment to test the effects of nicotine on the heart rate of rats. What are the disadvantages of having too small a sample size (i.e., testing on too few rats)? What are the disadvantages of having too large a sample size (i.e., testing on too many rats)?

3. Explain the difference between discrete variables and continuous variables. Give an example of each.

4. Explain the difference between quantitative and categorical variables. Give an example of each.

5. What is a null hypothesis?

6. What are some steps that scientists can take in designing an experiment to avoid false negatives?

Graphing Practice

Graphing is an important procedure used by scientists to display the data that is collected during a controlled experiment. Line graphs must be constructed correctly to accurately portray the data collected.

A graph contains five major parts: Title The independent variable The dependent variable The scales for each variable A legend

The TITLE: depicts what the graph is about. By reading the title, the reader should get an idea

about the graph. It should be a concise statement placed above the graph.

The INDEPENDENT VARIABLE: is the variable that can be controlled by the experimenter. It

usually includes time (dates, minutes, hours, etc.), depth (feet, meters), and temperature

(Celsius). This variable is placed on the X axis (horizontal axis).

The DEPENDENT VARIABLE: is the variable that is directly affected by the independent

variable. Example: How many oxygen bubbles are produced by a plant located five meters below

the surface of the water? The oxygen bubbles are dependent on the depth of the water. This

variable is placed on the Y-axis or vertical axis.

The SCALES for each Variable: In constructing a graph one needs to know where to plot the points

representing the data. In order to do this a scale must be employed to include all the data points. The

scales should start with 0 and climb based on intervals such as: multiples of 2, 5, 10, 20, 25, 50, or 100.

The scale of numbers will be dictated by your data values.

The LEGEND: is a short descriptive narrative concerning the graph's data. It should be short

and concise and placed under the graph.

The MEAN for a group of variables: To determine the mean for a group of variables, divide the

sum of the variables by the total number of variables to get an average.

The MEDIAN for a group of variables: To determine median or “middle” for an even number of

values, put the values in ascending order and take the average of the two middle values.

Example: 2, 3, 4, 5, 9, 10. Add 4+5 (2 middle values) and divide by 2 to get 4.5.

The MODE for a group of variables: The mode for a group of values is the number that occurs

most frequently. Example: 2, 5, 8, 2, 6, 11. The number 2 is the mode because it occurred

most often (twice).

Problem A:

Using the following data to answer the questions below and then construct a line graph.

Number of bubble per minute

Depth in meters Plant A Plant B

2 29 21

5 36 27

10 45 40

16 32 50

25 20 34

30 10 20

1. What is the dependent variable and why?

2. What is the independent variable and why?

3. What are the mean, median, and mode of all three columns of data?

Depth : Mean_______ Median _______Mode____

Bubble Plant A.: Mean_______ Median _______Mode____

Bubbles Plant B: Mean_______ Median _______Mode____

4. Title: ______________________________________________________________________________

__________________________________________________________________________________

Problem B: Diabetes is a disease affecting the insulin producing glands of the pancreas. If there is not enough insulin being produced by these cells, the amount of glucose in the blood will remain high. A blood glucose level above 140 for an extended period of time is not considered normal. This disease, if not brought under control, can lead to severe complications and even death.

Answer the following questions concerning the data below and then graph it.

Glucose mL per Liter of Blood

Time After Eating (Hours) Person A Person B

0.5 170 180

1 155 195

1.5 140 230

2 135 245

2.5 140 235

3 135 225

4 130 200

1. What is the dependent variable and why? 2. What is the independent variable and why?

3. What title would you give the table above?

4. Which, if any, of the above individuals (A or B) has diabetes?

5. What data do you have to support this conclusion?

6. If the time period were extended to 6 hours, what would the expected blood glucose level for Person B? Explain why.

Title: __________________________________

_______________________________________________________________________________________

Problem C:

Temperatures were obtained in November in a fairly arid area of Nevada. At two different sites,

temperature readings were taken at a number of heights above and below the soil surface. One site

was shaded by a juniper (a plant) whereas the other was not.

Condition Height in cm from soil surface Temperature (OC)

Beneath Forest cover Unshaded Field

Air 150 18 20

Air 90 18 21

Air 60 18 20

Air 30 18 21

Soil Surface 0 16 33

Humus -6 12 19

Mineral -15 9 15

Mineral -30 7 12

Construct a line graph, plot the data, and give an appropriate title in the space below.

Problem D:

A researcher interested in the disappearance of fallen leaves in a deciduous forest carried out a field experiment that lasted nearly a year. She collected all the leaves from 100 plots scattered throughout the forest. She measured the amount of leaves present in November, May and August. The percentages reflect the number of leaves found, using the November values as 100 percent. Complete the table by calculating the missing percentages.

Collection Date Ash Beech Elm Hazel Oak Willow

November 4271g

100%

3220g

100%

3481g

100%

1723g

100%

5317g

100%

3430g

100%

May 2431g

57%

3190g

91%

1739g

______%

501g

_______%

4401g

83%

1201g

35%

August 1376g

32%

2285g

71%

35g

______%

62g

_______%

1759g

33%

4g

0.1%

Construct an appropriate line graph for the ash and elm leaves on the graph below.

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Problem E: A species of insect has been accidentally introduced from Asia into the US. The success of this

organism depends on its ability to find a suitable habitat. The larval stage is very sensitive to

changes in temperature, humidity and light intensity. Expose to situations outside the tolerance

limits results in a high mortality (death) rate. Study the data table below.

Temperature (oC)

Mortality (%)

Relative Humidity (%)

Mortality (%)

Light Intensity (fc)

Mortality (%)

15 100 100 80 300 0

16 80 90 10 400 0

17 30 80 0 600 10

18 10 70 0 800 15

19 0 60 0 1000 20

20 0 50 50 1200 20

21 0 40 70 1400 90

22 0 30 90 1600 95

23 20 20 100 1800 100

24 80 10 100 2000 100

25 100 0 100 2200 100

Plot line graphs for the effects of temperature and humidity on mortality rates.

Name: ______________________________________________________________________ Date: _________________ Block: _____________

Cell Structure and Function Research the following structures and/or organelles found below using a variety of online resources, this does not include your friends or fellow students. In your own words describe the function of each structure. Structures underline should also include a diagram. These functions should go above and beyond the definitions that were given during first year biology. You will need to commit these structures to memory. Every Wednesday you will be assessed on this material by taking a quiz (1st Quarter: Matching, 2nd Quarter: Multiple Choice Questions, and 3rd Quarter: Free Response).

Structure Function Nucleoid

Nuclear envelope

Cytoplasm

Organelle

Cytosol

Plasma membrane

Endomembrane system

Vesicles

Central vacuole

Cytoskeleton

Nucleus

Nucleolus

Ribosomes

Rough endoplasmic reticulum

Smooth endoplasmic reticulum

Golgi apparatus

Lysosomes

Peroxisome

Contractile vacuole

Mitochondria

Chloroplast

Flagella

Cilia

Cell wall

The Evolution of Cells Click on the following link: http://learn.genetics.utah.edu/content/cells/organelles/ and answer the questions that follow.

1. Describe how the Earth’s atmosphere has changed over time. How has this impacted the type of organisms that evolved?

________________________________________________________________________________________________________________________

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2. Describe how the endosymbiotic theory got its name. __________________________________________________________________________

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3. “Mitochondria and chloroplast have striking similarities to bacteria cells.” Explain what evidence is used to support this statement.

________________________________________________________________________________________________________________________

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________________________________________________________________________________________________________________________

4. Describe the pattern of inheritance for mitochondrial DNA (mtDNA). _______________________________________________________________

________________________________________________________________________________________________________________________

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Name: ____________________________________________________ Block: _______ Date: ____________

Amazing Cells: Cell Communication Web Activity Click on the following link: http://learn.genetics.utah.edu/content/cells/ Once the webpage opens you will see a number of different boxes on which you can click. In this activity you will focus on the column of five links found on the right-hand side of the webpage under the heading Cells Communicate. Follow the instructions below and answer the questions that go along with each portion to increase your understanding of cell communication. Part 1: The Inside Story of Cell Communication

Read through The Inside Story of Cell Communication to get a brief summary of what cell communication

involves. Take notes in the space provided below.

Part 2: The Fight or Flight Response 3D-Animation

1. What part of our body is often the first to detect signals from our environment?

_____________________________________________________________________________________

2. What are the two primary ways that signals get sent through the body?

_____________________________________________________________________________________

3. What does the video propose could be considered a cell’s sole purpose of life?

_____________________________________________________________________________________

_____________________________________________________________________________________

4. In your own words, what is a signaling cascade?

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

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5. List and describe the physical reactions that occur due to a triggered stress response.

a. _______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

b. _______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

c. _______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

d. _______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

6. According to the video, an identical signaling molecule can cause either relaxation or contraction of

different types of muscle cells in our bodies. This is due to the different “protein machinery” found in the

various types of muscle cells. Explain the scientific reasoning behind this phenomenon.

_____________________________________________________________________________________

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_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

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Part 3: How Cells Communicate During Fight or Flight

7. When cortisol is released into the blood stream it begins a signaling cascade in several cell types. What

are the results?

a. _______________________________________________________________________________

b. _______________________________________________________________________________

c. _______________________________________________________________________________

8. In the animation you watched previously, the video referenced a “signaling molecule.” What are the two

names that can be used interchangeably for this signaling molecule?

a. ___________________________________________

b. ___________________________________________

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9. It has been reported that people can possess super-human strength when faced with an extreme or

stressful situation. Example: A grandmother is able to lift up a car in order to free her grandson who is

trapped underneath it. What is the possible scientific explanation for this boost in strength or energy?

Part 4: Dropping Signals: Take a break and enjoy dragging and dropping the different signals onto the

various types of cells to see what happens!

Part 5: When Cell Communication Goes Wrong

10. Summarize each of the five ways that cell communication can go wrong. Read each example provided by

this website to get you started; you can incorporate the examples given into your answers, but you will

require additional information from your textbook and/or internet research to fully explain how each of these

happen. Cite your sources please.

a. Losing the signal: ________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

b. When a signal does not reach its target: _______________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

c. When a target ignores its signal: _____________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

d. Too much signal: _________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

e. Multiple breakdowns: ______________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

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11. Find a treatment for a cell communication problem that interests you. (You may not use either of the two

already stated on this website.) Clearly state the problem, the treatment, and explain how that treatment

repairs the issue. Cite your sources please.

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Name: ______________________________________________________ Date: _________ Block: ________

Classification Worksheet

Use online resource to answer the following questions. This packet will serve as your notes on these terms.

1. Draw a gastrula and label the blastopore and tissue layers. Define the terms diploblastic and triplobastic.

What significance do these terms play in the level of complexity in an organism?

2. Contrast protostomes and deuterostomes. List two examples of each. ____________________________

________________________________________________________________________________________

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________________________________________________________________________________________

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________________________________________________________________________________________

3. Define what the following types of symmetry and list two examples of each.

Asymmetry

Radial Symmetry

Bilateral Symmetry

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4. Describe cephalization? _________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

5. There are three main types of body cavities found in animals. Define the following and list two examples of

each.

Acoelomate

Psuedocoelomate

Coelomate

________________________________________________________________________________________

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________________________________________________________________________________________

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Animal Development: We're Just Tubes - Crash Course Biology Watch the following video and take notes on information not covered in the questions above: https://www.youtube.com/watch?v=k_9MTZgAhv0

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Name: ____________________________________________________ Block: _______ Date: ____________

Creating Phylogenetic Trees from DNA Sequences: Student Worksheet Click on the following link: http://media.hhmi.org/biointeractive/click/Phylogenetic_Trees/01.html Answer the following questions as you proceed through the activity slides.

12. Briefly explain how scientists draw relationships between organisms based on shared anatomical features.

_____________________________________________________________________________________

_____________________________________________________________________________________

13. How are DNA sequences used to deduce evolutionary relationships? ______________________________

_____________________________________________________________________________________

14. What is one advantage of building phylogenetic trees using DNA comparisons rather than anatomical

features? _____________________________________________________________________________

_____________________________________________________________________________________

15. Watch the video clip on slide 3 and then draw a simple tree illustrating the evolutionary relationships

between gorillas, chimpanzees, humans, and orangutans.

16. Watch the short video on slide 4. How has biotechnology affected the process of building phylogenetic

trees from DNA sequences? ______________________________________________________________

_____________________________________________________________________________________

17. What do evolutionarily related organisms share? ______________________________________________

18. What are two common types of mutations? __________________________________________________

19. Watch the short animation on slide 6 and describe a SNP. ______________________________________

_____________________________________________________________________________________

20. Watch the short animation on slide 7 and described an indel. ____________________________________

_____________________________________________________________________________________

21. Explain the difference between distantly related and closely related organisms in terms of their DNA

sequences. ___________________________________________________________________________

_____________________________________________________________________________________

22. What does it mean to compare “apples to apples” when referring to DNA sequences from different

organisms? ___________________________________________________________________________

_____________________________________________________________________________________

23. Watch the short animations on slide 10 and explain what is meant by “aligning” DNA sequences.

_____________________________________________________________________________________

_____________________________________________________________________________________

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24. How is a SNP identified in an alignment? ____________________________________________________

_____________________________________________________________________________________

25. How is an indel identified in an alignment? ___________________________________________________

_____________________________________________________________________________________

26. Look at the information on slide 15. From left to right, identify the base in each box as an indel or a SNP.

Write your answers in the spaces below.

Box 1 (left) _________ Box 2 (center) _________ Box 3 (right) _________

Now click on each box and check your answers to question 15 above.

27. Watch the video clip on slide 17. How can you identify the two sequences that are most similar?

_____________________________________________________________________________________

28. Watch the video clip on slide 18 and describe the link between the length of the line and time.

_____________________________________________________________________________________

29. What is surprising about the placement of hippos on the phylogenetic tree?

_____________________________________________________________________________________

30. Define a branch point (also called a node) on a phylogenetic tree and describe what it represents.

_____________________________________________________________________________________

_____________________________________________________________________________________

31. What is the root? _______________________________________________________________________

_____________________________________________________________________________________

32. What does the node closest to the root represent? ____________________________________________

33. Describe what an unrooted phylogenetic tree represents. _______________________________________

_____________________________________________________________________________________

34. On slides 22 and 23, notice how phylogenetic trees can rotate around nodes and have different shapes.

Notice the relationships between the organisms do not change.

35. Using the information on slide 24, explain how DNA evidence supports the known biology of the seven

cone snails. ___________________________________________________________________________

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_____________________________________________________________________________________

36. Write three conclusions drawn from the information provided in this Click and Learn:

a. __________________________________________________________________________________

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__________________________________________________________________________________

b. __________________________________________________________________________________

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c. __________________________________________________________________________________

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Classification & Taxonomy Activity

The diversity of life on Earth is astounding. Each organism has a unique body plan which allows it to

survive and adapt to its surroundings. With such an abundance of species, classifying organisms into

different categories is necessary in order to assign each a scientific name and to understand its

evolutionary history. The diversity of living organisms is overwhelming, but after further research and

observation, many likenesses appear. These similarities become the basis for taxonomists to organize

organisms into their appropriate hierarchal categories.

Animals are classified into categories called taxa according to their body plan, phylogeny, and other

similar characteristics. There are seven principle levels that organisms can be placed into: Kingdom,

Phylum, Class, Order, Family, Genus, and Species. All animals are in the Kingdom Animalia. As you

move from kingdom to species, the animals that are grouped together become more closely related at

each succeeding level.

The next level after Kingdom is Phylum, which is the main focus of this activity. Even though there are

approximately thirty-five phyla within the animal kingdom, 98 percent of all animals are classified into eight

of them. To get even more specific, seven of the eight phyla are invertebrates. Invertebrates comprise

most of the animal kingdom, with almost 75 percent of all animals on earth being insects. They out

number humans by a million to one!

From Phylum, animals are then broken down into more specific categories. For example, a shark, a bird,

and a human are all in the Phylum Chordata. What similarities do these animals have? Taxonomists

agree that all these animals have a similar internal skeleton. However, these animals would not be

grouped in the same Class. This process would continue until the animal is classified down to Species.

Note that Sub-phyla do exist, and, there are visible differences not only amongst the different animal

phyla, but also within each phyla.

Procedure:

1. Review the phyla descriptions provided, highlight and take annotated notes on the characteristics

from each phylum.

2. The table on page ten provides a main characteristic of one of the eight main animal phyla in each

block. Using the information in this grid, list the characteristics applicable to each phylum in the

chart provided on the next page. The end product will be a comparison of the main characteristics

of each phylum. Note that some of the characteristics are used multiple times.

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Porifera

Sponges

The Phylum Porifera consists only of sponges. These animals are entirely aquatic; 98% are found only in

marine environments and a small percentage are found in freshwater lakes and streams. Sponges are

considered the oldest and of the animal phyla. Translated from Latin, Porifera means “pore bearer.”

Sponges play an important role in aquatic ecosystems, filtering particles, including bacteria, out of the

water. The surface of a sponge is covered with a skin that is one cell thick. This skin is penetrated by

numerous small pores and a few larger openings. These larger openings are the entrances and exits for a

complex system of canals and chambers through which the sponge pumps a current of water. The body

of a sponge, between this system of canals, is a loose assemblage of cells that secretes a supporting

skeleton of collagen fibers and mineral spicules made of glass or calcium carbonate. This body carries

out the process of growth, repair, nourishment, and reproduction.

Sponges can filter water at a rate equal to their entire volume in less than a minute. As the sponge pumps

in water at this rate, it captures tiny food particles as small as a single micron in diameter. Choanocytes

are specialized flagellated cells, also called collar cells that enable sponges to pump the water. Since

sponges are filter feeders they often have to filter over a ton of water to secure just a single ounce of food.

Sponges reproduce asexually by fragmentation or budding, sexually using eggs and sperm, or they are

hermaphroditic—a single species with both male and female gametes. Their commercial importance

includes use as bath sponges as well as being tested for possible anti-cancer drugs or antibiotics.

Sponges provide a micro-habitat for other organisms and they aid in cleaning their aquatic environments.

Since sponges are considered the simplest of the all animal phyla, they are important subjects for

analyzing the evolution of animals. Studies indicate that the Phylum Porifera is at the base of the animal

phylogenetic tree.

Features:

* Asymmetrical

* Organized as an assemblage of different kinds of specialized cells, e.g. collar cells

* No tissues

* Skeleton lacking or made of spicules

* Depends on system of water currents for food and oxygen

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Cnidaria

Jellyfish, Corals, Anemones, Hydras

The phylum Cnidaria includes jellyfish, corals, sea pens, sea anemones, and hydras. This phylum

contains the most venomous marine creature; the Australian box jellyfish. It is known to kill more people

than sharks, crocodiles, and stonefish combined. It can cause shock and heart failure within minutes. Sea

turtles are able to prey upon the box jellyfish because they are not affected by the venom. Most cnidaria

alternate between two different body forms throughout their life: a free-swimming form, called the medusa,

and a stationary form, called the polyp. Both body types follow the same basic plan. They are radially

symmetrical with three layers of tissue. Each species has a single opening that serves as both the mouth

and the anus. That shared opening is usually surrounded by a ring of tentacles, allowing the animal to

capture prey from all directions.

Cnidarians have a defined top and bottom and two distinct layers of tissue: an epidermis outer layer and

an internal gastrodermis. Between these tissue layers is a layer called the mesoglea. In the form of a

medusa, the mesoglea is an elastic, clear jelly with fibers made of protein called collagen. The mesoglea

aids in locomotion by elastically recoiling in response to muscle contractions. Cnidarians’ muscles and

nerves are located at the base of the tissue layers. The internal space, surrounded by the layers of tissue

and mesoglea, is the gut or gastrovascular cavity.

In order to capture prey, cnidarians have stinging cells. Located in their tentacles, these stinging cells,

called cnidocytes, contain tiny, often toxic harpoons, called nematocysts. Triggered by touch or certain

chemicals, nematocysts fire out of the cnidocyte housing at lightning speed. Some hydra can fire these

harpoons with an accelerated force equal to 40,000 times the acceleration of gravity. That’s 10,000 times

the acceleration force of a space shuttle. Once the nematocyst hits it mark, usually lethal poisons are

injected into the prey. The combination of defined tissues, muscles, nerves and a gut allowed ancestral

cnidarians to be the first animals on the planet to show animated behavior. The name Cnidaria comes

from the Latin word meaning “nettle.”

Features:

* Two tissue layers with nerve and muscle tissues

* Nematocysts - structures contained in special cells called cnidocytes or cnidoblasts that can act in both

offense and defense

* Two main life forms - free-swimming medusa (e.g. jellyfish) or stationary polyp (e.g. anemone)

* Radial symmetry

* Extracellular digestion in gastrovascular cavity

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Platyhelminthes

Flatworms

This particular phylum is one of the lesser-known groups and includes such animals as freshwater planaria, colorful marine polycads, and parasitic tapeworms and flukes. The name Platyhelminthes in Latin means “flat worm.” Fossilized worm tracks in the early Cambrian period hint at the origin of this body plan. While the classification of Platyhelminthes remains controversial because of the diversity within each class included in this phylum, flatworms share distinctive features. They are bilaterally symmetrical with a defined head and tail region and a centralized nervous system containing a brain and nerve cords. Clusters of light-sensitive cells make up what are called eyespots. The head region of the flatworm also contains other sense organs which are connected to the flatworm’s simple brain. Like most animals, with the exception of sponges and cnidarians, flatworms possess three tissue layers making them triploblastic. The middle tissue layer, called the mesoderm, helps form true organs including reproductive organs such as ovaries, testes, and a penis. Flatworms are hermaphroditic and capable of sexual and asexual reproduction. They have no circulatory system or body cavity (coelom), but they do have an excretory and digestive system. Passive diffusion through the skin supplies oxygen to their body parts. The highly branched gastrovascular cavity distributes nutrients to their cells. Most species of flatworms are parasitic—they have evolved protective skin coverings and elaborate attachment mechanisms to allow them to live inside their hosts. Features:

* Bilaterally symmetrical with a head and tail * Centralized nervous system * Three tissue layers * Acoelomate * No circulatory system

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Annelida Polychaetes, Earthworms, Leeches

The Cambrian period began approximately 543 million years ago. Of the eight major phyla, two were known from fossils at this time - Porifera and Cnidaria. Shortly thereafter, a profuse radiation of fossils representing the other animal body plans occurred over a relatively brief span of about 10 million years. The rest of the animal phyla evolved during, or shortly after, this evolutionary explosion of new life forms in the Cambrian period. The Annelid body plan is equal in complexity to that of chordates. Annelids are bilaterally symmetrical; they contain three tissue layers and are coelomates. The coelom surrounds a one-way muscular digestive tract that runs from the mouth to the anus and includes a pharynx, intestine, and other structures. Annelids have a closed-circulatory system and a segmented central nervous system that includes a simple brain located in the head region. One of the distinctive traits of an annelid is that it has segmentation—Annelida means “little ring” in Latin. Each segment has a number of bristles, called setae, which help the worm move. The evolution of segmentation is an important development for the annelids because it enabled the specialization of different body regions. Fluid-filled coelomic compartments were another important adaptation for annelids because it insulated the gut from locomotor muscles and provided a hydrostatic skeleton enabled these worms to swim and burrow. Features:

* Elongate, bilateral body with segmentation * Triploblastic * Well-developed coelom * Closed circulatory system * Bristle-like structures called setae projecting from body (except in leeches)

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Arthropoda Crustaceans, Spiders, Millipedes, Centipedes, Insects

Of all the phyla in the animal kingdom, Arthropoda is by far the largest and most diverse. All arthropods have segmented bodies and are covered in a hard, yet flexible exoskeleton. Their muscles attach to the inside of the exoskeleton. The name Arthropoda means “jointed foot” and refers to their jointed appendages. In order to grow, arthropods must shed their chitonous exoskeleton periodically in process called molting. When an arthropod goes through specific developmental stages it is called metamorphosis. Metamorphosis can bring on radical changes in body design; for example, a dragonfly begins its life in a pond as a swimming larva and then changes into a completely different-looking winged adult. Arthropods, like all animals, originated in the sea, but became the first animal group to live on land and take to the skies. This is likely because arthropods demonstrate a genetic predisposition to adapt to changing conditions. The diversity and success of the arthropods can be attributed to their versatile body plans. Key features of which lie in the development of myriad types of appendages: antennae, claws, wings, shields, and mouthparts. These characteristics enabled arthropods to exploit nearly every niche on Earth. Features:

* Hard exoskeleton made of chitin and protein * Jointed appendages * Segmented body * Grows through metamorphosis * Triploblastic * Open circulatory system * Reduced coelom * Bilaterally symmetrical

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Mollusca Clams, Snails, Slugs, Nautilus, Octopus

Animals in this phylum—chitons, snails, slugs, clams, squid, and octopi—show an amazing degree of diversity. All molluscs have soft bodies. In fact, the name Mollusc means “soft” in Latin. Most molluscs are covered by a hard shell, which is secreted by a layer of tissue called the mantle; the mantle overlays the internal organs of the mollusc. Molluscs also have a strong muscular foot, which is used for movement or grasping. They have gills, a mouth and an anus. One feature unique to molluscs is a file-like, rasping tool called a radula. This structure enables them to scrape algae off rocks, to drill through the hard shells of their prey, or catch fish. The diversity of molluscs demonstrates how a basic body plan can evolve into a variety of different forms that enable survival in specific environments. For example, the hard shell in a land-dwelling snail is relatively large and serves to protect the animal. However, in the fast-swimming squid the shell has been reduced to a small pen-shaped structure. Features:

* Rasping organ called a radula—present in all groups except bivalves and Aplacophora * Muscular foot—used for locomotion and other tasks * A sheath of tissue called the mantle that covers the molluscs’ body and can secrete the shell (if there is

one) * A mantle cavity that houses the gills or lungs * A calcium shell is present in most molluscs. Some molluscs have greatly reduced shells: squid. Others

have completely lost the shell feature: slugs, nudibranchs, and octopi. * Coelomate * Triploblastic * Most show bilateral symmetry

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Echinodermata Sea stars, Sea Lilies, Sea Urchins, Sea Cucumbers, Brittle Stars

There are about 6000 living species belonging to the phylum Echinodermata. The bodies of echinoderms are made of tough, calcium-based plates that are often spiny and covered by a thin skin. This tough body is how they get their name—Echinoderms (echino-spiny, derm-skin). Echinoderms are exclusively marine animals. This phylum includes sea stars, sea lilies, urchins, sea cucumbers, sand dollars and brittle stars. Echinoderms do not have a distinct head and tail. Instead, many Echinoderms begin life as bilaterally symmetrical larvae and later develop into organisms with pentaradial symmetry. The mouths of most Echinoderms are located on the underside of their bodies. Echinoderms move, feed, and respire with a unique water-vascular system ending in tube feet. Sea stars use their tube feet to slowly pry open clams, mussels, and other prey. Some sea stars can even extrude their stomachs from their bodies and insert them into the tiny openings between the two shells of bivalves and digest the soft bodies inside. An interesting ability of both sea stars and sea urchins is regeneration. If body parts such as legs, tube feet, or spines are lost they can grow back. Most echinoderms are either stationary or slow-moving but nevertheless prominent members of the marine environment. Features:

* Triploblastic * Coelomate * Internal skeleton made of small calcium plates * Five-part radial symmetry * Water-vascular system that operates the tube feet

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Chordata

Tunicates, Lancelets, Vertebrates including Amphibians, Reptiles, Mammals The Phylum Chordata includes a wide range of animals from tunicates that look like sponges, to vertebrates including fishes, frogs, snakes, birds, and humans. Despite this diversity most all chordates share certain characteristics at some point in their development. One of these features is a stiffening rod called a notochord that, in the vertebrates, is later replaced by a bony vertebral column. In most adult vertebrates the notochord remains as a disk between the vertebrae. Another chordate feature is the dorsal nerve cord that becomes the spinal cord and brain. Also included in the chordate body plan are structures called pharyngeal gill slits; these skeletal elements function as jaws and jaw supports, and can take on a variety of other functions.

The most conspicuous group of Chordates is the subphylum Vertebrata. Chordates have internal skeletons that enable chordates to grow continuously with no need for molting and can support a large mass. This feature has allowed some vertebrates to grow to large sizes; consider the African elephant or the giraffe. This internal skeleton is also credited with enabling the powerful movements of swimming fish.

A major embryonic development in the evolution of vertebrates is the appearance of the neural crest. The neural crest is a specialized population of undifferentiated, migratory cells that are correlated with the emergence of vertebrate jaws, skull, and a number of other structures that lead to more complex organisms. Another feature that likely added to the complexity of vertebrates was the duplication of HOX genes. Scientists speculate that additional copies of these genes that control organism body plans provided additional genetic material available to evolve a more complex organism. Both of these aforementioned features likely offered new opportunities for adaptation.

Vertebrates fall into two main categories: fishes and tetrapods. Tetrapods developed from a distinct lineage of fishes that possessed internal fin bones. These structures eventually aided in supporting the weight of animals on land and laid the foundation for arms and legs and the first amphibians. The development of a shelled amniotic egg enabled tetrapods to remain on land and develop into reptiles, birds, and mammals. From an ancient reptilian ancestor, two groups of animals, mammals and birds, independently developed the capacity to maintain a constant body temperature. Features:

* Notochord * Single, dorsal, tubular nerve cord * Phalangeal pouches * Segmentation * Post-anal tail * Bilateral symmetry

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Characteristic Table: A1

Bilateral phylum that added

segmentation

A2 Most have a

calcium-carbonate shell

A3 Five-part radial

symmetry

A4 Specialized cells, but not organized

into organs or tissues

A5 Mantle of tissue

covering the body

B1 Hollow body

cavity for food

B2 Three tissue layers, but no body cavity

B3 Fluid-filled

compartments used for

locomotion

B4 Jaws and skulls important in their

evolution

B5 Complete

digestive tract with two ends

C1 Most members

are parasitic

C2 Water flows

through its body, full of canals

C3 Pioneered jointed

legs

C4 First phylum to

venture into the air

C5 Some have

stinging structures (nematocysts)

D1 Increased

complexity made possible by

much more DNA

D2 Body design

basically a tube within a tube

D3 Tube feet used for

locomotion

D4 First muscle and

nerves

D5 Most have inside skeleton of bones

E1 All members live

in the ocean

E2 Some of the

simplest animals with bilateral

symmetry

E3 Digestive tract with the entrance being

the exit

E4 All have

notochord; most have backbone

E5 Champions of variations in appendages

F1 More species than any other

phylum

F2 Some spines are

little pinchers (pedicellaria)

F3 Some non-

swimming polyps

F4 Some free-drifting

medusae

F5 Some propel,

using their siphon as a water jet

G1 Muscular “foot”

used to slide, dig or jump

G2 No locomotion;

stationary animal

G3 Tubular mouth

(pharynx) at mid-body

G4 Phylum to which humans belong

G5 Hard but flexible

bodies with interlocking plates

under their skin

H1 Spicules act as a skeleton to give

it structure

H2 Feeding device like a toothed, rasping tongue

(radula)

H3 No symmetry or consistent body

shape

H4 Exoskeleton made

of chitin and protein

H5 Their active

burrowing has affected global

climate

Name ________________________________________________ Date_______________________

Class Period __________________________________________

Classification & Taxonomy Activity—Answer Sheet Porifera (5 characteristics)

Cnidaria (6 characteristics) Platyhelminthes (5 characteristics) Annelida (5 characteristics)

Arthropoda (7 characteristics) Mollusca (6 characteristics) Echinodermata (6 characteristics) Chordata (7 characteristics)