Unit 12 ~ 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. 12 NOTES: ARTHROPODS Arthropods are an. They are the. Arthropods are the on Earth. They. The various Classes of Arthropods are listed below: 1. Class Chilopoda -. 2. Class Diplopoda -. 3. Class Crustacea - 4. Class Arachnidia - 5. Class Insecta General Characteristics of Arthropods All arthropods have general characteristics in common. The most noticeable is their. All classes of arthropods have a strong flexible exoskeleton. The prefix and the many joints in this skeleton allow for movement along with a variety of appendages. What are the advantages of an exoskeleton?. It also provides allowing greater movement. The exoskeleton also forms Page 1 of 21
a. What are the disadvantages of an exoskeleton? The exoskeleton is not living tissue and therefore and must be to attack from other organisms. This is costly in terms of energy and may be part of the reason arthropods are. The exoskeleton so the strength advantage is lost. More energy would be required for movement and breathing if the size increases too much. Arthropods also exhibit. These advances in cephalization allow for the formation of a The simple eyes are like ours with the one lens focusing incoming light. In a compound eye light is focused with many smaller lenses. The which is important for avoiding predators and capturing prey. Contributing to the diversity of arthropods are the many different functions of their appendages. Different species of arthropods have. Centipedes and Millipedes. The Class name comes from Greek and means lip foot. Centipedes are characterized by long antennae and Page 2 of 21
that extend from the body. They are fast runners and are predatory. They can bite with their venomous forcipules. These claws are modified first appendages.. Diplopoda means double foot and these arthropods have. Millipedes are slow runners, don't bite, and are mainly scavengers. They eat decaying leaves and dead plants. Crustaceans General Characteristics that is and has such members as. The crustaceans all have. However, the. The head has five pairs of appendages. Two pairs of these appendages are and the other three are mouthparts. These appendages are. Page 3 of 21
The thorax also has five pairs of appendages that are legs. The first pair are and are used for eating and defense. The remaining pairs of legs are for. The abdomen is equipped with. In crustaceans that have a tail the are used to quickly swim backward. Respiratory and Circulatory Systems under water are located above the legs. This is the site where hemocyanin, a blue pigment due to copper content, picks up oxygen molecules to be used by the body. The. Therefore, crustaceans have an. Nervous System The nervous system of a crustacean is similar to that of an earthworm. There is a. The crustaceans have. Reproductive System The. Crustaceans are. Sperm is transferred to the female by the first set of specialized. The third set of swimmerettes on the female are where the ovaries are located and the swimmerettes also function to hold the fertilized eggs. Digestive System The digestive system of a crustacean is a. The near the mouth of the crustacean secretes digestive juices and begins external digestion. The stomach has two regions as Page 4 of 21
opposed to a crop and gizzard. The gastric mill portion functions as a gizzard grinding the food with chitinous teeth. The posterior portion filters out coarse food particles. Absorption of nutrients takes place in digestive glands as opposed to the intestine PLEASE LABEL THE CRAYFISH ANATOMY IN THE DIAGRAMS BELOW BEFORE PROCEEDING ANY FURTHER! Page 5 of 21
Page 6 of 21 BCLN BIOLOGY 11 Rev July 2014
Insects "We hope that, when the insects take over the world, they will remember with gratitude how we took them along on all our picnics." -Bill Vaughan Insects - Here are three very different beetles. The insects are the of animals and have the. They are the most abundant and diverse Class of Arthropods with 29 different Orders. Insects represent about that scientists have classified and named. This makes them the. Segmentation gives insects a wide range of body parts. These body parts have many functions and allow insects to take on many different roles in the environment. The body plan of the insect is always in three parts;. The head has a. This arrangement shows strong. The images below show a compound eye and specialized mouth parts. Page 7 of 21
The and in winged species. The last section is the abdomen where you will find most of the internal organs. The images below show the wings on a wasp and the modified rear appendage on an earwig. Insect Internal Organs Digestion Insects eat with specialized mouthparts which can be specialized for many different functions including. Once inside the mouth the digestive system of all insects is the same. The. It then goes to the gastric mill and is mechanically broken down and then to the stomach where it is chemically digested. Surrounding the joint between these two organs is the gastric cecum which is responsible for the absorption of nutrients. Excretion surround the intestine and collect the nitrogenous wastes from the blood and excrete it into the digestive tract. Respiration Small openings in the exoskeleton called. The Page 8 of 21
gas exchange takes place at the ends of these trachea. Movement of the body wall causes the air to move in and out of the system. Circulation A lies dorsally in an insect. The heart pumps blood around within an. Reproduction in Insects Insects use sexual reproduction only. They are very successful with short life spans which means rapid reproduction and increased variation and the potential for new adaptations. There are two cycles of developmental change found in insects. 1. Complete Metamorphosis. 2. Incomplete Metamorphosis Page 9 of 21
In both cases there is a major adaptive advantage. With both life cycles the. This means they are not in competition for similar resources and have a greater chance of survival. PLEASE LABEL THE GRASSHOPPER ANATOMY IN THE DIAGRAMS BELOW BEFORE PROCEEDING ANY FURTHER! Page 10 of 21
Page 11 of 21 BCLN BIOLOGY 11 Rev July 2014
Arachnids "If you want to live and thrive, let the spider run alive." - American Quaker Saying Arachnids include. This group has the cephalon and thorax fused to form the and each member has an abdomen. Arachnids have six pairs of appendages on the cephalothorax. They have. The other two pairs of appendages are the. The pedipalp is very noticeable in the scorpion and is more commonly called. The chelicera is a that is well developed in all members. Although most internal anatomy is similar to that of the insect, the respiration differs. On the inner body wall. These folds create a large surface area for gas exchange to take place. Page 12 of 21
12 PRACTICE: ARTHROPODS 1. Arthropods are the most dominant life form on Earth, representing approximately of the animal kingdom. (1 mark) 2. Arthropod refers to the fact that all members of this phylum have appendages. (1 mark) 3. All arthropods have an exoskeleton: a. What are two selective advantages associated with an exoskeleton? (2 marks) b. What are two disadvantages of an exoskeleton? (2 marks) 4. Class of Phylum includes centipedes which are distinguished by having one pair of legs on each body segment. (2 marks) Page 13 of 21
5. Class of Phylum includes millipedes which are distinguished by having two pairs of legs on each body segment. (2 marks) 6. Class of Phylum include crabs, crayfish, shrimp and lobster. (2 marks) 7. Describe the various appendages on a crustacean including where they are found and what they do. (10 marks) 8. Compare and contrast the circulatory systems of Crustaceans (Phylum Arthropoda) to that of Oligochaeta (Phylum Annelida) and that of Bivalves (Phylum Mollusca). (5 marks) Page 14 of 21
9. Most arthropods are dioecious: a. What does dioecious mean again? (1 mark) b. Identify at least two other animal phyla, that have been studied in Biology 11 thus far, that have dioecious members. (2 marks) 10. You have encountered several animal phyla, thus far in Biology 11, that have a tube-within-a-tube body plan: a. Identify at least three phyla that have this body plan. (3 marks) b. What is the scientific term for this body plan if it is partially lined with mesoderm and partially lined with endoderm? (1 mark) Page 15 of 21
c. What is the scientific term for this body plan if it is fully lined with mesoderm? (1 mark) 11. are considered the most successful class of animals in the world as they represent approximately 75% of all organisms on Earth. (1 mark) 12. Insects are characterized by having three body parts: a. (1 mark) b. (1 mark) i. which contains pairs of legs, and sometime (2 marks) c. (1 mark) 13. The gastric mill of insects is comparable to the of earthworms. (1 mark) 14. in the exoskeleton allow air to enter small tubes called the such that gas exchange can occur in insects. (2 marks) 15. How do insects' short life spans serve as a selective advantage? Please use your understanding of Darwin's theory of evolution and terms such as mutation, diversity, and survival to provide a well-explained answer. (5 marks) Page 16 of 21
16. Compare and contrast complete and incomplete metamorphosis. (3 marks) 17. What is a selective advantage of undergoing metamorphosis? (1 mark) 18. Class of Phylum includes spiders, ticks, scorpions and mites. (2 marks) 19. Compared to insects, arachnids have their cephalon and thorax fused to form a which has pairs of appendages, including the characteristic 4 pairs (or total) of legs of a spider and then a pair of chelicera (mouthparts) and a pair of pedipalps (claws or pinchers). (3 marks) ~ END OF BIOLOGY 11 UNIT 12 LEARNING GUIDE ~ Page 17 of 21
UNIT 12 ANSWER KEY 12 PRACTICE: ARTHROPODS 1. Arthropods are the most dominant life form on Earth, representing approximately of the animal kingdom. (1 mark) 2. Arthropod refers to the fact that all members of this phylum have appendages. (1 mark) 3. All arthropods have an exoskeleton: a. What are two selective advantages associated with an exoskeleton? (2 marks) - prevents drying out (desiccation) allowing insects to survive drier environments - provides excellent protection for internal organs b. What are two disadvantages of an exoskeleton? (2 marks) - cannot grow as internal components grow so must be periodically shed leaving the organism vulnerable - becomes very heavy as it increases in size and thus, limits the maximum size of the organisms 4. Class of Phylum includes centipedes which are distinguished by having one pair of legs on each body segment. (2 marks) 5. Class of Phylum includes millipedes which are distinguished by having two pairs of legs on each body segment. (2 marks) 6. Class of Phylum include crabs, crayfish, shrimp and lobster. (2 marks) 7. Describe the various appendages on a crustacean including where they are found and what they do. (10 marks) - antennae on cephalothorax = sensory reception and feeding - mouthparts on cephalothorax = feeding - claws on thorax = feeding and defense - legs on thorax = movement - swimmerettes on thorax = movement and reproduction Page 18 of 21
8. Compare and contrast the circulatory systems of Crustaceans (Phylum Arthropoda) to that of Oligochaeta (Phylum Annelida) and that of Bivalves (Phylum Mollusca). (5 marks) - Crustaceans and Bivalves = open circulatory systems where hemolymph circulates through heart, vessels and open space surrounding internal organs, ideal for organisms that exist in areas of frequent pressure changes and low metabolic rates such as found in colder water - Oligochaeta = closed circulatory system where blood is contained within blood vessels at all times barring injury, blood flows at higher pressure and velocity, ideal for animals with faster metabolic rates 9. Most arthropods are dioecious: a. What does dioecious mean again? (1 mark) - have two separate genders, a male that produces sperm and a female that produces eggs b. Identify at least two other animal phyla, that have been studied in Biology 11 thus far, that have dioecious members. (2 marks) - some Nematods (Aschelminthes), - some Annelids - some Molluscs 10. You have encountered several animal phyla, thus far in Biology 11, that have a tube-within-a-tube body plan: a. Identify at least three phyla that have this body plan. (3 marks) - Nematoda (Aschelminthes) - Annelida - Mollusca b. What is the scientific term for this body plan if it is partially lined with mesoderm and partially lined with endoderm? (1 mark) - pseudocoelomate c. What is the scientific term for this body plan if it is fully lined with mesoderm? (1 mark) - coelomate 11. are considered the most successful class of animals in the world as they represent approximately 75% of all organisms on Earth. (1 mark) 12. Insects are characterized by having three body parts: Page 19 of 21
a. (1 mark) b. (1 mark) i. which contains pairs of legs, and sometime (2 marks) c. (1 mark) 13. The gastric mill of insects is comparable to the of earthworms. (1 mark) 14. in the exoskeleton allow air to enter small tubes called the such that gas exchange can occur in insects. (2 marks) 15. How do insects' short life spans serve as a selective advantage? Please use your understanding of Darwin's theory of evolution and terms such as mutation, diversity, and survival to provide a well-explained answer. (5 marks) Insects' short life spans are accompanied by a rapid reproductive rate. The more rapid reproduction is the more often DNA is copied meaning the more opportunities for mutation. As well, because reproduction is sexual, the more rapid reproduction is the more often individuals' genetic materials are mixed and possibly recombined. Such mutations and recombinations lead to greater diversity and a greater potential for the existence of beneficial traits which likely leads to insects being able to survive a greater range of selective pressures such that they reproduce and pass on their beneficial traits. Thus, insects' short life span and accompanying rapid reproductive rates likely contribute to their ability to colonize a wide range of environments and thus, to survive. 16. Compare and contrast complete and incomplete metamorphosis. (3 marks) - incomplete metamorphosis = 3 stages (egg, nymph and adult), organism looks fairly similar throughout the last two stages, simply grows larger and develops a few more features - complete metamorphosis = 4 stages (egg, larva, pupa and adult), organism drastically changes form throughout the stages (such as from egg to caterpillar to pupa to butterfly) 17. What is a selective advantage of undergoing metamorphosis? (1 mark) - a selective advantage of metamorphosis is that the larval and adult stages typically feed on different things and occupy different niches and thus, they are not competing for resources Page 20 of 21
18. Class of Phylum includes spiders, ticks, scorpions and mites. (2 marks) 19. Compared to insects, arachnids have their cephalon and thorax fused to form a which has pairs of appendages, including the characteristic 4 pairs (or total) of legs of a spider and then a pair of chelicera (mouthparts) and a pair of pedipalps (claws or pinchers). (3 marks) Page 21 of 21