1. Life Functions

2. Nutrition:
Nutrition will include how an organism obtains food for the energy it will need to live as well as how it will break down that food in the process of digestion.
We can classify organisms into two main groups based on how they will obtain food:
Autotrophes will make their own food using the process of photosynthesis or chemosynthesis.
Heterotrophes must bring in food from their surroundings.

3. Obtaining Food: Autotrophes
Photosynthesis is the process used by organisms such as plants and some protists where the energy from light is converted into a usable form of energy that is then used to put carbon dioxide together and make sugar.
Chemosynthesis is the process used by organisms that need to make their own food but are not exposed to light (protists that live in caves or at the bottom of the ocean). This process follows the same steps as photosynthesis except the original source of energy is not light, it is inorganic compounds from the environment.

4. Obtaining Food: Heterotrophes
Endocytosis: each individual cell will bring in food particles by wrapping the cell membrane around the food and engulfing it.
Absorption: food particles that were digested outside of the cell are then absorbed straight through the cell membrane.
Filter Feeders: large amounts of water are collected by the organism who removes the food floating in the water and releases the water.
Carnivores: organisms that hunt and kill animals.

5. Obtaining Food: Heterotrophes
Omnivores: organisms that will eat both meat and vegetation.
Herbivores: organisms that eat only vegetation.
Detritivores: organisms that eat decaying organic matter.
Scavengers: organisms that eat meat that was killed by carnivores.
Important: organisms have specialized structures (teeth, beaks, mouth parts) that allow the organism to eat.

6. Digestion of Food: Autotrophes
Plants and other autotrophic organisms are going to perform cell respiration to break down the sugars they have created in order to release energy. Any minerals, vitamins, or other nutrients needed by the organism will be absorbed from the environment. Ex) plants use roots to absorb nitrogen from the soil.

7. Digestion of Food: Heterotrophes
Heterotrophes will need to break down the food they have obtained from the environment in order to extract the usable particles from the waste. This process is called digestion. After this occurs each individual cell will perform cell respiration or fermentation to obtain energy.

8. Digestion of Food: Heterotrophes
Unicellular organisms such as bacteria and protists as well as sponges will perform intracellular digestion. In this process each cell will create enzymes responsible for breaking down the food within the cell. The food is normally held in a vacuole where the enzymes are placed and digestion occurs. After digestion the “waste” is eliminated from the cell using exocytosis.

9. Digestion of Food: Heterotrophes
In extracellular digestion the food is broken down outside of the cell, normally in a digestive system, and then the nutrients are absorbed. Fungi and all kinds of animals except sponges use this method.
Fungi will secrete digestive enzymes into the environment and absorb what is broken down around them, they do not have a digestive system.

10. Digestion of Food: Heterotrophes
Gastrovascular cavity: this digestive system consists of one opening and a balloon shaped organ. The food goes into the cavity inside of the animal; the cells at the edge of the cavity secrete digestive enzymes and absorb the nutrients. The “waste” is release out the same opening it entered through. The animals that perform this type of digestion include cnidarians, platyhelminthes, and echinoderms.

11. Digestion of Food: Heterotrophes
Digestive tract: this system moves in one direction with two openings and specialized organs to perform different tasks.
The length of the tract is directly related to the food that is eaten. It will take longer to break down plant cell walls than animal cells that do not have cell walls so herbivores have longer digestive tracts than carnivores.

12. Digestion of Food: Heterotrophes
The organs of the digestive tract are also related to the food eaten and how. The tract will begin with specialized mouth parts followed by a pharynx and esophagus. If the food was swallowed whole the next organ is a crop that will moisten and store the food then a gizzard that will grind the food. If the food was chewed and then swallowed the next organ is a stomach that will release digestive enzymes. Regardless the next step is a series of intestines that will absorb the nutrients and any excess water before the “waste” is released through the anus.

13. Why do organisms need to either eat or create food?
What are autotrophs? Include 3 examples.
What are heterotrophs? Include 3 examples.
What types of organisms perform photosynthesis?
What is the purpose of photosynthesis (what does it make)?
What materials are required in order for photosynthesis to occur?
What is the difference between photosynthesis and chemosynthesis?
What are some organisms that perform chemosynthesis?
What is endocytosis?
Identify what the following organisms eat and an example of an organism that would fall into that category.
Carnivore
Omnivore
Herbivore
Scavenger
Detritivore

14. What is the relationship between and organisms mouth structures and their source of food?
How do plants obtain energy? How do they obtain materials to build cell structures?
What is intracellular digestion? What are some examples of organisms that use intracellular digestion?
What is extracellular digestion?
What is a gastrovascular cavity? Identify if this is intracellular or extracellular digestion. Identify some examples of organisms that have this type of digestion.
What is a digestive tract? Identify if this is intracellular or extracellular digestion. Identify some examples of organisms that have this type of digestion.
How does the length of the digestive tract correspond to the food being eaten?
What is the function of a crop and gizzard? Do all organisms have these organs? Why or Why not.

15. Respiration
The process of bringing in oxygen and getting rid of carbon dioxide. Remember the organisms that perform only fermentation will not need to perform this act. Also remember that material moves easiest across a thin moist membrane.
The simplest, smallest organisms such as bacteria, protists, fungi, sponges, cnidarians, and all three types of worms will use diffusion for each individual cell to obtain oxygen and get rid of CO2.

16. Respiration
Plants have openings on the undersides of leaves called stomata that are controlled by guard cells. When the guard cells are pulled apart and the stomata open, oxygen and carbon dioxide move freely in and out of the plant. However; this also causes the plant to lose water vapor in the process of transpiration so the stomata cannot stay open or the plant would wilt.

17. Respiration
Most aquatic animals that do not use diffusion for respiration will have gills. Gills are respiratory structures that will come into direct contact with the water in order to allow the oxygen dissolved in the water to diffuse through the membrane and into the blood stream. These animals include fish, juvenile amphibians, and aquatic mollusks.

18. Respiration
Animals that breathe air have multiple types of respiratory structures.
Tracheal tubes: insects have a series of tubes that span their entire body that will allow air to flow throughout and exchange oxygen and carbon dioxide with tissues.
Book lungs: spiders have thin membranes that are stacked similar to the pages of a book that will allow oxygen to be passed into the blood stream.

19. Respiration
Lungs: all mammals, birds, reptiles, and adult amphibians will use lungs to bring air into the body, allowing oxygen to go into the blood stream and CO2 to diffuse out.

20. Transport
The process that moves oxygen, carbon dioxide, nutrients, and wastes around the body.
The simplest organisms will use diffusion to move materials from cell to cell until the material has reached its destination. These organisms include bacteria, protists, green algae, bryophytes, sponges, cnidarians, platyhelminthes, and nematodes.

21. Transport
Seedless vascular plants, gymnosperms, and angiosperms all have vascular tissue (tubes to transport materials). There are two types of vascular tissue in these plants. Xylem is a vascular tissue that will transport water from the roots where it is absorbed through the rest of the plant. Phloem will transport the sugars made in the leaves throughout the rest of the plant.

22. Transport
Open circulatory system: animals such as insects and some (slower moving) mollusks use a system where blood carries the materials around the body, but the blood does not stay in blood vessels the entire time. The blood is pumped by a heart or contracting blood vessel through a series of tubes until it comes to a system of spongy cavities (sinuses) that allow the blood to come into direct contact with the individual cells. Eventually the blood returns to the blood vessels to be pumped again.

23. Transport
Closed circulatory systems are far more efficient because the blood stays in blood vessels the entire time. However there are several types.
Annelid worms have a closed system where five blood vessels called the aortic arches are going to contract to pump the blood where it needs to go.
Echinoderms have a closed system but the liquid in their system is water not blood. This is called a water vascular system.

24. Transport
Fish have a closed system where the blood moves in one continuous circle through the animal and a two chambered heart is responsible for pumping the blood. In this case the blood enters the atrium from the body and then goes to the ventricle where it is pumped to the gills to pick up oxygen. Then the blood travels through the rest of the body before returning to the atrium.

25. Transport
Amphibians, reptiles, birds, and mammals have a closed system where the blood makes two trips to the heart as it moves throughout the body allowing it to move faster. But there are two types of hearts for this two loop system:

26. Transport
Amphibians and most retiles have a three chambered heart where the blood enters the right atrium from the body, is passed into the only ventricle, is pumped to the lungs, returns to the left atrium, flows again to the same ventricle, and is pumped to the body. Since the ventricle is suppose to be sending blood to two different destinations, the blood in the ventricle mixes slightly and some ends up going to the wrong destination making this slightly inefficient.

27. Transport
The crocodilian family, birds, and mammals have a four chambered heart. The ventricle has split into a left and right ventricle ensuring that there is no mixing of blood. The steps are the same as the three chambered heart except now there are two different ventricles.

28. What is respiration?
When moving materials from one side of a membrane to another what does then membrane need to be?
What is diffusion? Does it require energy? What types of organisms use diffusion to bring in oxygen and remove CO2?
What are stomata? What types of organisms have stomata? What are they used for?
What is transpiration? What types of organisms experience transpiration? Why is transpiration a negative thing?
What are gills and how do they function? What are some examples of organisms that have gills?
What are tracheal tubes and what types of organisms use them?
What are book lungs and what types of organisms use them?
What are lungs and what types of organisms use them?

29. What is the function of transport?
What types of organisms use diffusion for transport?
What is xylem and phloem? What are their functions? What types of organisms have these structures?
Explain the process of an open circulatory system. What types of organisms use this system? Is this more or less efficient than a closed system? Explain why.
Explain a closed circulatory system.
What is special about the circulatory system of an annelid worm? Of a starfish?
Explain the circulation of blood in fish. In amphibians and reptiles. In birds and mammals.
List the types of closed systems in order of increasing efficiency.

30. Excretion
The process that eliminates waste created by each individual cell as they break down proteins and controls the amount of water in the organism. The waste created is a nitrogen based molecule called ammonia and is extremely toxic to living tissues. This is not the same as the leftover food that was not used in digestion. The elimination of that waste was part of the digestive system.
Simple organisms such as bacteria, protists, plants, sponges, cnidarians, and nematodes are capable of diffusing this toxic substance out of the body.
The rest of the organisms turn ammonia into a less harmful substance (either uric acid or urea), collect it all in one place, and then release it from the body.

31. Excretion
In aquatic animals most of the waste is eliminated using the same surface used for respiration (gills or skin). The excretory systems in these animals are more related to maintaining the proper water balance. In flatworms flame cells collect excess water and pump it out of the body. In fresh water fish and amphibians kidneys collect excess water and eliminate it. In salt water fish excess salt is also passed through the respiratory surface and the urine created by the kidneys is very concentrated.

32. Excretion
Terrestrial animals must eliminate waste but they must also conserve water. All of these organisms will pump body fluid that has collected the waste from around the body through a structure that will remove and concentrate this waste. Worms and mollusks use a structure called nephridia. Insects and spiders use a structure called malpighian tubes. Birds, reptiles, amphibians, and mammals use kidneys. Once the waste is removed from the blood it is released from the body.