1. Chapter 1 From Cells to Ecosystems

2. Lesson 1 Cells

3. What are cells? An organism is a living thing made of the same tiny building blocks. A cells is the smallest unit of living things that can carry out the basic processes of life. A unicellular organism is made of a single cell that carries out its life processes.

4. An amoeba is unicellular organism. Multicellular organisms are made up of more than one cell.

5. What is inside an animal cell? Plant and animal cells have several basic structures, called organelles, that help them perform life perform life processes. The cell membrane is a layer around the outside of the cell. The cell membrane gives the cell its shape.

6. The cell membrane controls what materials move into an out of the cell. Cytoplasm is a gel-like liquid that fills the region inside the cell membrane. The cytoplasm supports all the cell’s structure. The nucleus is the cell’s control center.

7. The nucleus is a large, round organelle found in the center of the cell. The nucleus sends signals to all other parts of the cell. Mitochondria are oval, membrane-covered organelles that supply energy for the cell. Mitochondria break down food, which releases energy for the cell to use.

8. A vacuole is a membrane-covered structure used for storage. Vacuoles store water, food, and wastes.

10. What is inside a plant cell? Plant cells have many of the same structures and organelles as animal cells, but there are some additional organelles that animals cells do not have. Plants have a stiff structure outside the cell membrane called the cell wall. The cell wall gives the plant cell extra strength and support.

11. Vacuoles store excess water and provides extra support. Plants make their own food in structures inside their cells called chloroplasts. Chloroplasts is a green structure where the energy from sunlight is used to produce food for the plant.

12. Chloroplasts are green because they contain chlorophyll. Chlorophyll is able to use the energy in sunlight. Chloroplasts are mostly found in leaf and stem cells.

14. How are cells organized? Similar cells working together at the same job form a tissue. A group of tissues that work together to perform specific function form an organ. Organs that work together to perform a certain function make up an organ system.

15. Lesson 2 Relationships in an Ecosystem

16. What is in an ecosystem? Living things in an ecosystem are called biotic factors. Examples of biotic factors are plants, trees, animals. Nonliving things in an ecosystem are called abiotic factors. Examples of abiotic factors are water, soil, rocks, and air.

17. An ecosystem includes all living and nonliving things in an environment. The organisms an ecosystem are separated into populations. A population is all the members of a single species in an area at a given time. Example: All the blue spruce trees in a forest are one population.

18. All of the populations in an ecosystem can be put together to make up a community. One community could include thousands of populations.

19. How are food chains alike? The path that energy and nutrients follow in an ecosystem is called a food chain. The path that energy and nutrients follow in an ecosystem is called a food chain. Food chains are the feeding relationships in an ecosystem. Food chains are the feeding relationships in an ecosystem. All of the energy in a food chain starts with the Sun. All of the energy in a food chain starts with the Sun. Producers are organisms that use the Sun’s energy to make their own food in the form of sugar. Producers are organisms that use the Sun’s energy to make their own food in the form of sugar.

20. How are food chains alike? Plants are producers. Plants are producers. Producers have the most energy in a food chain and are at the base of an energy pyramid. Producers have the most energy in a food chain and are at the base of an energy pyramid. A consumer is any animal that eats plants or other animals. A consumer is any animal that eats plants or other animals. A primary consumer is a consumer that eats the producer. A primary consumer is a consumer that eats the producer.

21. How are food chains alike? A secondary consumer is the consumer that eats the primary consumer. A secondary consumer is the consumer that eats the primary consumer. Herbivores are consumers that eat only producers. Herbivores are consumers that eat only producers. Examples of herbivores: squirrels, some birds, grazing animals. Examples of herbivores: squirrels, some birds, grazing animals. Carnivores are consumers that eat other animals and not producers. Carnivores are consumers that eat other animals and not producers.

22. How are food chains alike? Examples of carnivores: hawks, lions, panthers. Examples of carnivores: hawks, lions, panthers. Omnivores are consumers that eat both plants and other animals. Omnivores are consumers that eat both plants and other animals. Examples of omnivores: raccoons, humans, mice. Examples of omnivores: raccoons, humans, mice. Scavengers are consumers that eat leftover bodies after they have started to rot. Scavengers are consumers that eat leftover bodies after they have started to rot.

23. How are food chains alike? Vultures and raccoons are examples of scavengers. Vultures and raccoons are examples of scavengers. Decomposers are at the end of a food chain and they break down dead or decaying plants and animals. Decomposers are at the end of a food chain and they break down dead or decaying plants and animals. Fungi, bacteria, worms, and termites are all types of decomposers. Fungi, bacteria, worms, and termites are all types of decomposers.

27. What are food webs made of? A food web is a network of food chains that have some links in common. A food web is a network of food chains that have some links in common. To read a food web, the arrow points to what eats the other organism. To read a food web, the arrow points to what eats the other organism. A predator is an animal that hunts other animals for food. A predator is an animal that hunts other animals for food. Prey are organisms that are eaten by other animals. Prey are organisms that are eaten by other animals.

28. What are food webs made of? Predators are important in food webs because they keep the prey population smaller so resources do not run out in an ecosystem. Predators are important in food webs because they keep the prey population smaller so resources do not run out in an ecosystem.

31. What are symbiotic relationships? Interdependence is the reliance of certain organisms on other organisms for their survival. Interdependence is the reliance of certain organisms on other organisms for their survival. Symbiosis is a relationship between two or more organisms that lasts over time. Symbiosis is a relationship between two or more organisms that lasts over time. There are 3 types of symbiotic relationships: mutualism, commensalism, and parasitism. There are 3 types of symbiotic relationships: mutualism, commensalism, and parasitism.

32. What are symbiotic relationships? Mutualism is a relationship where both organism benefit. Mutualism is a relationship where both organism benefit. Example of mutualism: a pollinator and a flowering plant. The pollinator gets nectar from the plant and the plant gets the pollen transferred to another flower. Example of mutualism: a pollinator and a flowering plant. The pollinator gets nectar from the plant and the plant gets the pollen transferred to another flower. Commensalism is a relationship that benefits one organism without harming the other. Commensalism is a relationship that benefits one organism without harming the other.

33. What are symbiotic relationships? Example of commensalism: remoras and sharks. Remoras get food scraps, transportation, and protection. The remora does not help or hurt the shark. Example of commensalism: remoras and sharks. Remoras get food scraps, transportation, and protection. The remora does not help or hurt the shark. Parasitism is a relationship where one organism benefits and the other is harmed. Parasitism is a relationship where one organism benefits and the other is harmed. A parasite lives in or on a host organism and benefits from the relationship. A parasite lives in or on a host organism and benefits from the relationship.

34. What are symbiotic relationships? Example of parasitism: ticks and dogs. Ticks are the parasite that feeds on dogs, which are the hosts. Example of parasitism: ticks and dogs. Ticks are the parasite that feeds on dogs, which are the hosts.

35. Lesson 3 Photosynthesis

36. What is photosynthesis? Sunlight is a form of energy that plants use to make their food. Photosynthesis is the process of making food using sunlight. Photosynthesis only happens in cells that have chloroplasts.

37. Sunlight, water, and carbon dioxide are needed to perform photosynthesis. The end result of photosynthesis is sugar and oxygen.

38. What do leaves do? Leaves have the job of carrying out photosynthesis. Leaves have the job of carrying out photosynthesis. Water is absorbed through the roots. Water is absorbed through the roots. Carbon dioxide enters the plant through the air into the stomata. Carbon dioxide enters the plant through the air into the stomata. Stomata are tiny pores on the underside of the leaves. Stomata are tiny pores on the underside of the leaves.

39. What do leaves do? The stomata are opened and closed by two guard cells. The stomata are opened and closed by two guard cells. The guard cells open and close the stomata in response to the amount of water and light the plant receives. The guard cells open and close the stomata in response to the amount of water and light the plant receives. If the plant has too little water, the guard cells close the stomata. If it has too much water, the guard cells open the stomata and let out water. If the plant has too little water, the guard cells close the stomata. If it has too much water, the guard cells open the stomata and let out water.

40. What do leaves do? Photosynthesis occurs in chloroplasts in the epidermis. Photosynthesis occurs in chloroplasts in the epidermis. The epidermis is the outermost layer of a leaf. The epidermis is the outermost layer of a leaf. The top leaf surface has a waxy cuticle, a waterproof layer that prevents moisture from evaporating. The top leaf surface has a waxy cuticle, a waterproof layer that prevents moisture from evaporating. Carbon dioxide + water -------  sugar + oxygen Carbon dioxide + water -------  sugar + oxygen

41. What is the photosynthesis and respiration cycle? The sugar produced in photosynthesis is a carbohydrate. The sugar produced in photosynthesis is a carbohydrate. A carbohydrate is a group of substances made from carbon, hydrogen, and oxygen. A carbohydrate is a group of substances made from carbon, hydrogen, and oxygen. Animals take in these carbohydrates when they eat a plant. Animals take in these carbohydrates when they eat a plant.

42. What is the photosynthesis and respiration cycle? Oxygen that is produced by photosynthesis is breathed in by animals during repiration. Oxygen that is produced by photosynthesis is breathed in by animals during repiration. The energy in carbohydrates is released when the cells of organisms use oxygen to break down the sugars in the process called cellular respiration. The energy in carbohydrates is released when the cells of organisms use oxygen to break down the sugars in the process called cellular respiration.

43. What are energy pyramids? An energy pyramid is a diagram that shows the amount of energy available at each level of an ecosystem. An energy pyramid is a diagram that shows the amount of energy available at each level of an ecosystem. The bottom of the energy pyramid is producers. The bottom of the energy pyramid is producers. There are fewer numbers of organisms and less energy the higher the level in the pyramid. There are fewer numbers of organisms and less energy the higher the level in the pyramid.

44. Lesson 4 Changes in Ecosystems

45. How can ecosystems change? Ecosystems can be changed by natural events or by living organisms. Ecosystems can be changed by natural events or by living organisms. Natural events include natural disasters such as earthquakes, floods, storms, hurricanes, volcanoes, and drought. Natural events include natural disasters such as earthquakes, floods, storms, hurricanes, volcanoes, and drought. People can try to repair the damage from natural disasters, but they cannot prevent them. People can try to repair the damage from natural disasters, but they cannot prevent them.

46. How can ecosystems change? Animals can change ecosystems by building homes. Animals can change ecosystems by building homes. A population can grow out of control causing harm to other populations. A population can grow out of control causing harm to other populations. Human can introduce new organisms to an environment causing threat to those native species. Human can introduce new organisms to an environment causing threat to those native species.

47. How do people affect the environment? Pollution is a harmful change to the natural environment. Pollution is a harmful change to the natural environment. How people affect land How people affect land Strip-mining: removing the topsoil from dirt to remove minerals. The topsoil has all of the nutrients which wash away into lakes and streams. Strip-mining: removing the topsoil from dirt to remove minerals. The topsoil has all of the nutrients which wash away into lakes and streams. When crops are harvested, there is very little nutrients left in the soil for future crops. When crops are harvested, there is very little nutrients left in the soil for future crops.

48. How do people affect the environment? Trees are cut down Trees are cut down Roads bring more vehicles which let off gas and leak oil Roads bring more vehicles which let off gas and leak oil How People Affect Water and Air How People Affect Water and Air Factories dump waste and chemicals into lakes and rivers Factories dump waste and chemicals into lakes and rivers Oil leaks from ships Oil leaks from ships Fertilizers and pesticides soak into the ground or flow into lakes and rivers, harming fish, birds, and mammals. Fertilizers and pesticides soak into the ground or flow into lakes and rivers, harming fish, birds, and mammals.

49. How do people affect the environment? When people burn fuel to power factories, heat homes, or drive vehicles, air pollution is produced. When people burn fuel to power factories, heat homes, or drive vehicles, air pollution is produced. Smog is a combination of smoke and fog that can irritate eyes, nose, and throat Smog is a combination of smoke and fog that can irritate eyes, nose, and throat Acid rain occurs when air pollution mixed with moisture in the atmosphere. Acid rain occurs when air pollution mixed with moisture in the atmosphere. Acid rain pollutes water and soil, kills plants and fish, and damages stone and metal. Acid rain pollutes water and soil, kills plants and fish, and damages stone and metal.

50. How does waste affect the land? Most of the garbage ends of in landfills Most of the garbage ends of in landfills Household garbage may contain harmful substances Household garbage may contain harmful substances Some garbage is biodegradable, or able to break down naturally over a short period of time. Some garbage is biodegradable, or able to break down naturally over a short period of time. Other garbage is nonbiodegradable and can build up over time. Other garbage is nonbiodegradable and can build up over time.

51. How does waste affect the land? Toxic waste must be disposed of carefully so it does not pollute the soil, groundwater, rivers, and lakes. Toxic waste must be disposed of carefully so it does not pollute the soil, groundwater, rivers, and lakes. Common household items can contain hazardous components Common household items can contain hazardous components Three Rs of conservation: reduce, reuse, and recycle. Three Rs of conservation: reduce, reuse, and recycle.

52. How does waste affect the land? We can reduce the amount of natural resources we use. We can reduce the amount of natural resources we use. Reusing materials saves resources. Reusing materials saves resources. We can recycle materials to make them into other products. We can recycle materials to make them into other products.

53. What happens when ecosystems change? Organisms must respond to these changes in order to survive. Organisms must respond to these changes in order to survive. Some organisms migrate to a place where they are more likely to survive. Some organisms migrate to a place where they are more likely to survive. Other organisms respond by adapting to ecosystem changes. Other organisms respond by adapting to ecosystem changes. Individual species could begin to die. Individual species could begin to die.

54. What happens when ecosystems change? Extinct species are organisms that have completely died out. Extinct species are organisms that have completely died out. When a species is in danger of becoming extinct, it is called an endangered species. When a species is in danger of becoming extinct, it is called an endangered species. Species with low numbers that could become endangered are called threatened species. Species with low numbers that could become endangered are called threatened species.

55. What happens when ecosystems change? Pollution, overhunting, disease, and competition from newly introduced organisms can cause a species to die out. Pollution, overhunting, disease, and competition from newly introduced organisms can cause a species to die out. The biggest threat to the survival of most organisms is habitat loss. The biggest threat to the survival of most organisms is habitat loss.

56. How do ecosystems come back? The process of one ecosystem changing into a new and different ecosystem is called succession. The process of one ecosystem changing into a new and different ecosystem is called succession. Primary succession takes place in a community where few living things exist, or where earlier communities were wiped out. Primary succession takes place in a community where few living things exist, or where earlier communities were wiped out. Primary succession occurs in barren, lifeless areas that have little or no soil. Primary succession occurs in barren, lifeless areas that have little or no soil.

57. How do ecosystems come back? Pioneer species are the first species living in a lifeless area. Pioneer species are the first species living in a lifeless area. A climax community is the final stage of succession. A climax community is the final stage of succession.

58. What is secondary succession? Secondary succession is the beginning of a new community where another community previously existed. Secondary succession is the beginning of a new community where another community previously existed. Secondary succession occurs faster than primary succession. Secondary succession occurs faster than primary succession.