Cells and Systems

1. Cells and Systems By: Vivek and Dhvani 8N-4

2. Driving Question

3. How do scientists make sense of the vast diversity of living things? • Scientists make sense of the vast diversity of things by categorizing them into different categories. • For example, they separate Uni Cellular and Multi Cellular organisms. • Uni Cellular organism are living things with only one cell. Multi cellular organisms are living thins with more than one cell. • Scientists also use kingdoms to classify living organisms.

4. Uni Cellular Multi Cellular

5. How do scientists make sense of the vast diversity of living things? • Living organisms are divided into 5 major kingdoms including Monera, The Protista(Protoctista), the Fungi, the Plantae, and the Animalia. • Kingdom Monera includes about 10 000 species. They are made up of a small single cell(unicellular). Mostly bacteria. • Kingdom Protista includes about 250 000 species. They are made up of a large single cell(also unicellular). An example is algae.

6. How do scientists make sense of the vast diversity of living things? • Kingdom Fungi includes about 100 000 species. They are multicellular organism. An example is a mushroom. • Kingdom Plantae includes about 250 000 species. They are also multicellular and they are autotrophic. (photosynthesis). An example is a plant/tree. • Kingdom Animalia includes about 1 000 000 species. They are multicellular animals without cell walls and without photosynthetic pigments. An example would be humans or animals (elephants).

8. How do scientists make sense of the vast diversity of living things? • Scientist also use phylum. • The animal kingdom is divided into 40 smaller groups, known as phylum. Here, animals are grouped by their main features. Animals usually fall into one of five different phylum which are Cnidaria (invertebrates), Chordata (vertebrates), Arthropods, Molluscs and Echinoderms. • The phylum group is then divided into even smaller groups, known as classes. The Chordata (vertebrates) phylum splits up into Mammalia (Mammals), Actinopterygii (Bony Fish), Chondrichthyes (Cartilaginous Fish) , Aves (Birds), Amphibia (Amphibians) and Reptilia (Reptiles).

9. Kingdom Plant Animal Phylum Class

10. How do scientists make sense of the vast diversity of living things? • Each class is divided into small groups again, known as orders. The class Mammalia (Mammals), splits into different groups including Carnivora, Primate, Artiodactyla and Rodentia. • In every order, there are different families of animals which all have very similar features. The Carnivora order breaks into families that include Felidae (Cats), Canidae (Dogs), Ursidae (Bears), and Mustelidae (Weasels).

12. How do scientists make sense of the vast diversity of living things? • Every animal family is then divided into small groups known as genus. Each genus contains animals that have very similar features and are closely related. For example, the Felidae (Cat) family contains genus including Felis (small Cats and domestic Cats), Panthera (Tigers, Leopards, Jaguars and Lions) and Puma (Panthers and Cougars).

15. How do scientists make sense of the vast diversity of living things? • Example 2 - Orang-utanKingdom: Animalia (Animal)Phylum: Chordata (Vertebrate)Class: Mammalia (Mammal)Order: PrimatesFamily: Hominidae (Great Apes)Genus: Pongo Species: Pongo pygmaeus (Orang-Utan)

17. Part A Cells

18. What are the characteristics of all living things? • Living organisms: • Need energy • Respond and adapt to their environment • Reproduce • Grow • Produce waste

19. What is the basic unit of all living things? • The basic unit of all living things are cells. • All living organisms are made up of cells. The cell is the most important characteristic that living organisms share.

20. What is cell theory? • The cell theory is that all living things are composed of one or more cells. • Cells are the basic units of structure and function in all organisms. • All Cells arise from pre-existing, living cells.

21. Who invented the first microscope? What types of microscopes are used today? • Anton Van Leeuwenhoek is sometimes credited with the invention of the first microscope. Zacharias Jansen made the first optical telescope. He is also credited for inventing the first truly compound microscope. Robert Hooke is also credited for inventing the microscope. However the origin of the microscope, just like the origin of the telescope, is a matter of debate.

22. Types of Microscopes • Compound Microscopes • Dissection or Stereoscope • Confocal Microscopes • Scanning Electron Microscope (SEM) • Transmission Electron Microscopes (TEM)

23. Compound Microscopes • Compound microscopes are light illuminated. The image seen with this type of microscope is two dimensional. This microscope is the most commonly used. You can view individual cells, even living ones. It has high magnification. However, it has a low resolution. Cell

24. Dissection or Stereoscope • A dissection microscope is light illuminated. The image that appears is three dimensional. It is used for dissection to get a better look at the larger specimen. You cannot see individual cells because it has a low magnification Earthworm

25. Confocal Microscopes • This microscope uses a laser light. This light is used because of the wavelength. Laser light scans across the specimen with the aid of scanning mirrors. Then image is then placed on a digital computer screen for analyzing. Salt

26. Scanning Electron Microscope (SEM) • SEM use electron illumination. The image is seen in 3-D. It has high magnification and high resolution. The specimen is coated in gold and the electrons bounce off to give you and exterior view of the specimen. The pictures are in black and white. Mosquito

27. Transmission Electron Microscopes (TEM) • TEM is electron illuminated. This gives a 2-D view. Thin slices of specimen are obtained. The electron beams pass through this. It has high magnification and high resolution. Plant Cell

28. What types of microscopes are used today? • Today we use light microscopes and electron microscopes. • A light microscope (has 2 lenses) and can magnify up to 2000x. This is still not enough to see some of the smaller structure of cells. • For this, scientist use electron microscopes, which use beams instead of light. The electrons are bounced off the sample, and then enlarged to form an image on a television screen or photographic plate. • Electron microscopes can magnify up to 2 000 000x. The first electron microscope was built in Germany in 1932.

29. Light Microscope Electron Microscope

30. What are the two categories of all living things? Give Examples. • Single cellular – Paramecium and viruses. These are smaller and less complex organisms. Ex. Paramecium • Multi cellular – Humans and plants. These are more complex organisms and larger in size. Ex. Humans

31. What are the structures in cells called in general (you need to get specific with either a plant or animal cell)? • Structures in a cell are called organelles. • Each organelle has a role to play in the survival of the cell and organism.

32. Animal Cells • Cell Membrane: Surrounds and protects the contents of the cell. It helps control the movement of substances in and out of the cell. • Cytoplasm: Its jellylike. It constantly moves inside the cell and distributes materials such as oxygen and food to different parts of the cell. • Nucleus: Controls the cells activities. It contains the chromosomes – structures made of genetic material that direct a cells growth and reproduction. The nucleus is enclosed by a nuclear membrane, which controls what enters and leaves the nucleus. • Vacuoles: Balloon like substances within the cytoplasm that are places for surplus food, wastes, and other stuff that the cell can’t use right away. Vacuoles are surrounded by a membrane.

33. Animal Cells Cont. • Centrosome: a small body located near the nucleus, it has a dense center and radiating tubes. This is where microtubules are made. • Golgi Body: a flattened, layered, sac-like organelle that looks like a stack of pancakes and is located near the nucleus. It produce the membrane that surround the lysosomes. • Lysosome: round organelles surrounded by a membrane and containing digestive enzymes. This is where the digestion of the cell nutrients takes place. • Mitochondrion: spherical to rod-shaped organelles with a double membrane. The inner membrane is infolded many times, forming a series of projections (called cristae). The mitochondrion converts the energy stored in glucose into ATP (adenosine triphosphate) for the cell.

34. Animal Cells Cont. • Ribosome: small organelles composed of RNA (rich cytoplasmic granules) that are sites of protein synthesis. • Nuclear membrane: the membrane that surrounds the nucleus. • Rough Endoplasmic Reticulum (rough ER):a vast system of interconnected, infolded and complex sacks that are located in the cell's cytoplasm. Rough ER is covered with ribosomes that give it a rough appearance. Rough ER transports materials through the cell and produces proteins in sacks called cisternae (which are sent to the Golgi body, or inserted into the cell membrane).

35. Animal Cells Cont. • Smooth Endoplasmic Reticulum (smooth ER): a vast system of interconnected, infolded and complex tubes that are located in the cell's cytoplasm. Smooth ER transports materials through the cell. It contains enzymes and produces and digests lipids (fats) and membrane proteins. Smooth ER buds off from rough ER, moving the newly-made proteins and lipids to the Golgi body, lysosomes, and membranes.

37. What are the main differences between plant and animal cells and explain why there are the differences. • Plant cells have a cell wall and chloroplasts and animal cells don’t. • Cell walls give the plant cell support (because they don’t have skeletons) and chloroplasts are where photosynthesis occurs.

38. Explain why cells are so small and do they get bigger when organisms grow? • To carry out their work cells need oxygen, water and food. They must also get rid of wastes. These materials must enter the cell membrane, go to the middle and then wastes must exit the membrane. If a cell was very big, this process would take way too long and be difficult to keep going. Large cells would also produce too much waste. When organisms get bigger, they add more cells. The cells don’t actually get bigger. Most cells in plants and animals have a diameter between 10-50 micrometers. Bacteria cells are much smaller. They are only 1-5 micrometers across.

39. Explain the process of fluids and nutrients moving in and out of a cell. • Materials move into the cell through the cell membrane by osmosis. Only certain materials can move through the selectively permeable cell membrane. • In cells, nutrients move from an area of higher concentration outside the cell to an area of lower concentration inside the cell. This is done by the process of diffusion. • Wastes then move from an area of higher concentration inside the cell to an area of lower concentration outside the cell. This again is done by diffusion. • Diffusion is when a substance moves from an area of higher concentration to an area of low concentration.

40. Describe at least four specialized cells that are found in humans • Multi celled organisms have many different cells that have different shapes and perform different jobs. • The muscle cell, skin cell, nerve cell, and bone cell are found in humans.

41. Muscle Cell • The muscle cell has an elongated shape and its function is to move body parts. Diagram Under a microscope

42. Skin Cell • The skin cell has a flat and brick shape and its function is to form protective layer. Diagram Under a microscope

43. Nerve Cell • The nerve cell has a long and branch like shape and its function is to deliver messages to the body. Diagram Under a microscope

44. Bone Cell • The bone cell has a thick walled shape and its function is to provide support. Diagram Under a microscope

45. Part B Systems

46. What are the parts of the digestive system? • Mouth – Food broken down by chewing and chemical action of saliva. • Salivary Glands - Saliva contains enzymes that break down carbohydrates into smaller molecules. • Esophagus - The esophagus is a long tube that uses rhythmic, wave-like muscle movements (called peristalsis) to force food from the throat into the stomach. • Stomach - Food in the stomach is partly digested and mixed with stomach acids • Liver - Makes bile which breaks down fats and some blood proteins. Helps the small intestine in digestion.

47. What are the parts of the digestive system? • Gall Bladder -  It stores and releases bile into the small intestine. • Pancreas - Enzymes from the pancreas help in the digestion of carbohydrates, fats and proteins in the small intestine. • Small Intestine – bile, pancreatic enzymes, and other digestive enzymes produced by the inner wall of the small intestine help in the breakdown of food. Most food is absorbed here. • Large Intestine - The large intestine is responsible for absorption of water and excretion of solid waste material. • Rectum – Feces are stored here. • Anus –Where feces exits the body.

48. The Nervous System • The nervous system coordinates and controls the actions of the organs and organ systems. It detects processes and responds to stimuli in the environment. The main parts of the nervous system are the brain, spinal cord and the nerves.

49. The Nervous System • Brain- It helps to control all of the body systems and organs, keeping them working like they should. The brain also allows us to think, feel, remember and imagine. • Spinal Cord - The brain communicates with the rest of the body through the spinal cord and the nerves. Information passed through the spine tells the body what to do and when to do it. • Nerve Cells - Neurons carry messages in the form of an electrical impulses. The messages move from one neuron to another to keep the body functioning

50. Explain how multi cellular organisms are organized and what some of the benefits are of being a multi cellular organism. • Organization: • Cells with the same structure and function form tissue. • Tissue forms organs. • Organs work together and make systems. • Systems work   together to form an organism. • Advantages: • Multi celled organisms: • Live in a wide variety of environments. • Can grow very large. • Obtain energy from many sources. • Have complex bodies.