Cells and Systems

Cells and SystemsBy: Vivek and Dhvani8N-4

Driving Question

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.

Uni CellularMulti Cellular

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.

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).

7How do scientists make sense of the vast diversity of living things?Scientist also use phylum.Theanimalkingdom is divided into 40 smaller groups, known as phylum. Here,animalsare grouped by their main features.Animalsusually 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).

KingdomPlantAnimal

Phylum

Class

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 ofanimalswhich all have very similar features. The Carnivora order breaks into families that include Felidae (Cats), Canidae (Dogs), Ursidae (Bears), and Mustelidae (Weasels).

How do scientists make sense of the vast diversity of living things?Everyanimalfamily is then divided into small groups known as genus. Each genus contains animalsthat 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).

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: PongoSpecies: Pongo pygmaeus (Orang-Utan)

Part ACells

What are the characteristics of all living things?Living organisms:Need energyRespond and adapt to their environmentReproduceGrowProduce waste

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.

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.

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.

Types of MicroscopesCompound MicroscopesDissection or Stereoscope Confocal MicroscopesScanning Electron Microscope (SEM)Transmission Electron Microscopes (TEM)

Compound MicroscopesCompound 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.

CellDissection 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

EarthwormConfocal 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.

SaltScanning 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.

MosquitoTransmission 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 CellToday 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.

What types of microscopes are used today?

Light MicroscopeElectron MicroscopeWhat are the two categories of all living things? Give Examples.Single cellular Paramecium and viruses. These are smaller and less complex organisms. Ex. ParameciumMulti cellular Humans and plants. These are more complex organisms and larger in size.Ex. Humans

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.

Animal CellsCell 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 cant use right away. Vacuoles are surrounded by a membrane.

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.

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).

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.

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 dont.Cell walls give the plant cell support (because they dont have skeletons) and chloroplasts are where photosynthesis occurs.

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 dont 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.

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.Describe at least four specialized cells that are found in humansMulti 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.

Muscle CellThe muscle cell has an elongated shape and its function is to move body parts.

Under a microscope DiagramSkin CellThe skin cell has a flat and brick shape and its function is to form protective layer.

Under a microscopeDiagramNerve CellThe nerve cell has a long and branch like shape and its function is to deliver messages to the body.

Under a microscopeDiagramBone CellThe bone cell has a thick walled shape and its function is to provide support.

Under a microscopeDiagramPart BSystems

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 acidsLiver - Makes bile which breaks down fats and some blood proteins. Helps the small intestine in digestion.

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.

The Nervous SystemThe 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.

The Nervous SystemBrain - 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

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.

Explain how blood is the transportation system for the body.Blood is the transportation system for the body because it circulates around the body to deliver food particles, dissolved gas, water, oxygen, sugars, hormones and proteins. They also remove waste that cells produce, like dead/tangled proteins. They remove dead cells. Blood also transports white blood cells to fight any disease/infection.

What are the main components of blood and their function?The blood has a number of components, primarily the plasma, red blood cells, platelets and white blood cells. Function:Blood carries food and oxygen to cells, as well as carrying wastes away from cells. Blood also carries disease fighting white blood cells through the body. It also helps maintain constant body temperature.

PlasmaPlasma is the liquid portion of the blood.The plasma is a substance responsible for carrying much of the elements of the blood, for example red and white blood cells, various proteins, fatty acids and urea. It also caries nutrients, carbon dioxide, waste products, and hormones.

Red Blood CellsRed blood cells carry oxygen around your body, acting as transporters.

White Blood CellsWhite blood cells are involved in your innate and active immune systems helping to combat viruses, bacteria and other harmful pathogens.

PlateletsPlatelets help the blood to clot so that heavy bleeding does not occur when you cut or hurt yourself. When there are not enough platelets in the blood, you may bruise or bleed easily.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Circulatory SystemDisorders of the circulatory system are the leading cause of death in North America. Caused By: High blood pressure (hypertension) which can lead to heart attacks (damage to heart muscle) and strokes (brain damage)Doctors use a sphygmomanometer to measure blood pressure.Smoking, lack of exercise, poor diet, and high cholesterol causes high blood pressure.High-fat diets can cause fats such as cholesterol to build up inside arteries. As arteries narrow and become blocked, tiny tears in their walls cause blood clots that can travel to the brain cause a stroke.Also, blood flow through the arteries can become very limited or stop, causing a heart attack.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Digestive SystemCancer is a disease caused by an uncontrolled division of abnormal cells in a part of the body and each is classified by the type of cell that is initially affected.Cancer harms the body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors. Tumors can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Digestive SystemStomach cancer, also called gastric cancer, is a tumor arising from the lining of the stomach. There has been a significant decrease in the number of people diagnosed with stomach cancer in the past 60 years.Stomach cancer may often be cured if it is found and treated at an early stage. Unfortunately, the outcome is poor if the cancer is already at an advanced stage when discovered. In most cases, stomach cancer is found at later stages.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Digestive SystemThe exact cause of stomach cancer is unknown, but a number of factors can increase the risk of the disease, including:Gender -- men have more than double therisk of getting stomach cancer than women.Race -- being African-American or Asian may increase your risk.Genetics -- genetic abnormalities and some inherited cancer syndromes may increase your riskGeography --stomach cancer is more common in Japan, the former Soviet Union, and parts of Central America and South America.Blood type -- individuals with blood group A may be at increased risk.Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Digestive SystemAdvanced age -- stomach cancer occurs more often around ages 70 and 74 in men and women, respectively.Family history of gastric cancer can double or triple the risk of stomach cancer.Lifestyle factors such as smoking, drinking alcohol, and eating a diet low in fruits and vegetables or high in salted, smoked, or nitrate-preserved foods may increase your riskHelicobacter pylori (H. pylori) infection of the stomach. H. pylori is a bacterium that infects the lining of the stomach and causes chronic inflammation and ulcers.Certain health conditions including chronic gastritis, pernicious anemia, gastric polyps, intestinal metaplasia, and prior stomach surgery.Work-related exposure due to coal mining,nickel refining, and rubber and timber processing and asbestos exposure.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Digestive SystemLong-term emotion stress, smoking, or excessive use of alcohol or aspirin can lead to a peptic ulcer. A peptic ulcer occurs when the unprotected wall of the stomach or small intestine is damaged by excess stomach acid.Peptic ulcers can usually be cured by heavy doses of antibiotic.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Respiratory SystemOur respiratory system is lined with cells with cilia, small hair like projections. These cilia beat continuously to remove airborne particles.Poisons in cigarette some and pollutants irritate this lining, causing mucus-producing cells to produce more mucus.At first you can remove the mucus by coughing. Over time, however, the irritated lining will become inflamed, leading to a condition called bronchitis.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Respiratory SystemBronchitis can be treated, but if the irritation continues, the ciliated cells will be destroyed and the mucus-producing cells will multiply. If this continues for a long time, the respiratory airways will narrow and become blocked. Eventually, the bronchitis can lead to a condition called emphysema. Some people inherit this disease, but its major cause is smoking.

Choose three systems of the body then name and describe at least two common disorders of that system. Be sure to explain how doctors think those disorders are caused.Respiratory SystemSmoking is the leading cause of lung cancer. Lung cancer occurs when certain compounds in the tar and the smoke contact lung tissue and cause cells to grow out of control. Large clusters of these uncontrolled cells begin to out-compete the healthy cells for nutrients. The healthy cells are killed, and the cancerous cells continue to divide, leading to cancer.

With those same three body systems from above, now explain what we can do to keep those systems healthy and avoid any disorders from happening to them.A Healthy Circulatory SystemLiving a healthy lifestyle keeps your circulatory system healthyA healthy lifestyle would include keeping the heart healthy so it can do its job properly by pumping blood around your body. It also includes eating healthy and getting enough exercise.A healthy person doesnt smoke, is at a healthy weight, eats a balanced healthy diet, thinks positively, feels relaxed, exercises regularly, has good relationships, and benefits from a good life balance.

With those same three body systems from above, now explain what we can do to keep those systems healthy and avoid any disorders from happening to them.A Healthy Digestive SystemImportant Nutrients in food that lead to a healthy digestive system:Carbohydrates provide the body with main source of energyFats are essential as they provide us with energy and cushion our organsProteins are essential for muscle growth and repair of tissues. If you eat too many protein sources you are eating excessive protein which could do many thing to your body.

A Healthy Digestive System contd.What too much protein can do to you:Weight gain. Excess calories from excess protein may be stored as body fat.Intestinal irritation. Too much protein has been linked to constipation, diarrhea and/or excessive gas.Dehydration. Experts advise drinking a half gallon of water per 100 grams of protein.Increase in liver enzymes.Nutritional deficiencies. Just focusing on protein intake causes some high-protein dieters to overlook other nutrients. Ensure that your diet is balanced and nutritious.Risk of heart disease. This is a bit misleading. A healthy high-protein diet is not associated with heart disease. But if you are getting all of your protein from unhealthy sources that are loaded in unhealthy fats, obviously the risk for heart disease will increase.Kidney problems. Some believe that high protein and low carbohydrate diets when done long term can possibly cause kidney issues, but more research needs to be done.

Examples Of ProteinWith those same three body systems from above, now explain what we can do to keep those systems healthy and avoid any disorders from happening to them.A Healthy Respiratory SystemSurrounding yourself with healthy air inside and outside the house keeps your respiratory system healthy

Give me your response to this fact (How do you feel about this and what do you think should be done to remedy this):Almost 60% of all Canadian adults and 26% of our children and adolescents are overweight or obese.I feel that people dont care too much about their health .This is horrible and many fatal things can happen if you become overweight or obese.Today we think about the cure, and not about prevention. We should think about preventing this issue instead of finding a cure.

Give me your response to this fact (How do you feel about this and what do you think should be done to remedy this):Almost 60% of all Canadian adults and 26% of our children and adolescents are overweight or obese.Also the government and schools should promote being healthy. There are apple schools but not every school is an apple school all over the world.An apple school is a school that promotes healthy foods. For example they would only let you eat healthy foods at snack.Also we need more physical education time so we have a better workout and become more fit.

Give me your response to this fact (How do you feel about this and what do you think should be done to remedy this):Almost 60% of all Canadian adults and 26% of our children and adolescents are overweight or obese.Also more people need to be aware of this issue. Many people dont know about it. We think the government should help promote a healthy life style and also schools to especially kids. They could promote healthy eating, spending time outside, being active, rather than staying inside and playing games. Because the kids will grow up and teach their kids. If they dont know about this issue, their will be many problems with the next generation.

Give me your response to this fact (How do you feel about this and what do you think should be done to remedy this):Almost 60% of all Canadian adults and 26% of our children and adolescents are overweight or obese.What obesity could do to you:Coronary heart diseaseType 2 diabetesCancers (endometrial, breast, and colon)Hypertension (high blood pressure)Dyslipidemia (for example, high total cholesterol or high levels of triglycerides)StrokeLiver and Gallbladder diseaseSleep apnea and respiratory problemsOsteoarthritis (a degeneration of cartilage and its underlying bone within a joint)

Bibliorgraphyhttp://mrshacksclass.edublogs.org/Mr. Shacks PowerPoint NotesScience Focus 8 https://www.google.ca/imghp?hl=en&tab=wi&ei=n8VRUvGnJ-POyAGs-YCABA&ved=0CAQQqi4oAg http://www.enchantedlearning.com/subjects/animals/cell/http://www.enchantedlearning.com/subjects/plants/cell/ http://a-z-animals.com/reference/animal-classification/http://www.webmd.com/cancer/stomach-gastric-cancer

Thank You!Thank You(Basic)

To reproduce the video effects on this slide, do the following:

On the Home tab, in the Slides group, click Layout, and then click Blank.On the Insert tab, in the Media group, click Video, and then click Video from File. In the left pane of the Insert Video dialog box, click the drive or library that contains the video. In the right pane of the dialog box, click the video that you want and then click Insert.Under Video Tools, on the Format tab, in the Sizing group, click the arrow to the right of Size launching the Format Video dialog box, select Size from the left pane and under Size in the right pane do the following:Click the Lock Aspect Ratio box.In the Height box, enter 6.03.In the Width box enter 8.03. Also in the Format Video dialog box, click Border Color in the left pane, under Border Color in the right pane select Solid Line, and then click the arrow to the right of Color, and under Theme colors select Black, Text 1, Lighter 25% (fourth row, second option from left).Also in the Format Video dialog box, select Border Style in the left pane, under Border Style in the right pane set the Width to 15 pt.Also in the Format Video dialog box, select Shadow in the left pane, under Shadow in the Right pane, click the arrow to the right of Colors and under Theme Colors, select Black, Text 1 (first row, second option from left), and then do the following:In the Transparency box, enter 60%.In the Size box, enter 100%.In the Blur box, enter 21 pt.In the Angle box, enter 40 degrees.In the Distance box, enter 19 pt.Also in the Format Video dialog box, select 3-D Format in the left pane, under Bevel in the right pane click the arrow to the right of Top and under Bevel, select Relaxed Inset (first row, second option from left), and then do the following:To the right of Top, in the Width box, enter 6 pt.To the right of Top, in the Height box, enter 16.5 pt.On the Home tab, in the Drawing group, click Arrange, point to Align, and then do the following: Click Align Center.Click Align Middle. Under Video Tools, on the Playback tab, in the Video Options group, select Loop until Stopped.On the Animations tab, in the Animation group, select Play.On the Animations tab in the Timing group, click the arrow to the right of Start and select With Previous.

To reproduce the text effects on this slide, do the following:

On the Insert tab, in the Text group, click Text Box, and then on the slide drag to draw a text box.Type text in the text box (Thank You or whatever text suits your message).Select the text, on the Home tab, in the Font group, select Garamond from the Font list, select 88 pt from the Font Size list, and then click on the Bold icon.Also in the Home tab, in the Font group, select the arrow to the right of the Font Color Icon, and then under Theme Colors, select White, Background 1 (first row, first option from left).With the text box selected, under Drawing Tools, on the Format tab, click the arrow in the bottom right corner of the WordArt Styles group, click the arrow opening the Format Text Effects dialog box. In the Format Text Effects dialog box, click 3-D Format on the left pane, under Bevel on the right pane, click the arrow next to Top and under Bevel select Relaxed Inset (first row, second option from left). Set the Width to 5 pt and the Height to 3 pt.Also in the 3-D Format right pane, under Surface, click the arrow next to Material and under Special Effect select Dark Edge (first row, first option from left).Also in the 3-D Format right pane, under Surface, click the arrow next to Lighting and under Neutral select Soft (first row, third option from left).Also in the 3-D Format right pane, under Surface, set the Angle to 290 Degrees.Close the Format Text Effects dialog box.

To reproduce the background effects on this slide, do the following:

On the Design tab, in the bottom right corner of the Background group, click the arrow at the bottom right corner launching the Format Background dialog box.In the Format Background dialog box, select Fill in the left pane, and under Fill in the right pane select Solid fill, then click the arrow to the right of Color and under Theme Colors select White, Background 1, Darker 50% (sixth row, first option from left).Close the Format Background dialog.

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