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Viruses, Bacteria, Protists, Fungi Chapter 7 Grade 7 Science.

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Presentation on theme: "Viruses, Bacteria, Protists, Fungi Chapter 7 Grade 7 Science."— Presentation transcript:

1 Viruses, Bacteria, Protists, Fungi Chapter 7 Grade 7 Science

2 Viruses _____ - a tiny, non-living particle invades and then multiplies inside of a living cell. Viruses can only multiply when they are _____ of a living cell. ______ - a living thing that provides the energy source for a virus. ________ - organisms that live on or in a host and can cause it harm. Viruses act like parasites but they are not ___________. Virus inside host parasite organisms

3 Structure of Viruses Viruses have three distinct shapes: – _________ – _______ – ________ All viruses have two basic parts: 1. A __________ that protects the virus 2. A ___________ made of genetic material round rods threads Protein coat Inner core

4 Virus Structure and Host Cells Viruses are like ______ that fit into ______ which is a protein on the surface of a host cell. ______________ - the shape of surface proteins allows the proteins to fit into a only certain proteins that are located on the surface of the host. ______________ - a virus that infects bacteria and has a robot-like shape. keyslocks Lock and Key action bacteriophage

5 How Viruses Multiply After a _________ attaches to a ________ it enters the cell. After the virus enters the cell, the ____________ takes over many of the cell’s functions. The ___________ instructs the cell to produce the virus’s proteins and genetic material. The ________ and ___________ continue to multiply into new viruses virusHost cell genetic material proteinsgenetic material

6 Active Viruses ___________ - enter cells and immediately begin to multiply leading to the quick death of the invaded cells. _____________ - “hide” for a while before becoming active inside of the host cell. The hidden virus hides inside of the host cells ___________ before it becomes active. Active Viruses Hidden Virus Genetic material

7 Viruses and Diseases ________ cause ________ Viral diseases are spread through ________, _________, _____________, and ___________. _________ - a substance introduced into the body to stimulate the production of chemicals that destroy specific disease causing viruses and organisms – a ___________ measure. Virusesdiseases contact bites Drops of moisture Body fluids Vaccine preventative

8 Bacteria ________________ - discovered bacteria in the late 1600’s. __________ - single celled organisms with no nucleus. __________ - the genetic material is not contained in the nucleus. Bacteria cells have _______ and __________ Anton van Leeuwenhoek bacteria prokaryotes Cell wallCell membrane

9 Bacteria – Structure

10 Bacteria - Size

11 Obtaining Food and Energy Bacteria must have : 1._____________ 2.______________ Some Bacteria are __________ - self feeders Bacteria make their food in 2 ways: 1.______________ 2._______________________________________ Some bacteria are __________ - other feeders that feed on other organisms or the food that other organisms make. Source of food Energy supply autotrophs Suns energy Energy from chemical substances in the environment heterotrophs

12 Respiration _________ comes from breaking down food in the process of __________. Some bacteria need ________ for respiration Others do not need ________ - these bacteria are called __________ and will die in the presence of oxygen. energy respiration oxygen anaerobic

13 Reproduction Bacteria need the following for reproduction: 1.___________ 2.___________ 3._______________ ________________ - reproductive process that requires only one parent. - ___________ - one cell divides to form two identical cells – each cell gets its own complete copy of the parents cell’s genetic material, ribosomes and cytoplasm food temperature Suitable conditions Asexual Reproduction Binary fission

14 Reproduction Continued ______________ - two parents combine their genetic material to produce a new organisms. – _________ - one bacterium transfers some genetic material to another and then the cells separate. – Bacteria can survive harsh conditions by forming __________ - a small, round, thick-walled, resting cell that forms inside a bacterial cell. - endospores can resist _________, _______, and ______ - they can survive for many years Sexual reproduction conjugation endospores freezingheating drying

15 Bacteria in Nature Bacteria are involved in: – ______________________ – ___________________________ – _________________ Scientists believe that _________________ were responsible for adding oxygen to the Earth’s atmosphere. Bacteria keep oxygen levels in the air ________. Oxygen and food production Environmental recycling and cleanup Health maintenance Medicine Production Autotrophic bacteria stable

16 Food Production / Environmental Recycling __________- named after Louis Pasteur, is a process where beverages such as milk and juices are heated to a temperature high enough to kill harmful bacteria without destroying the taste. ___________ - are “nature’s recyclers” – return basic chemicals such as ______ to the environment for other living things to use. Pasteurization Decomposers nitrogen

17 Recycling and Nitrogen-Fixing ________________ break down chemicals in leaves and branches that drop to the ground. Once these materials are broken down, they mix with soil and can be absorbed from _______ of nearby plants. ________________ live in soils and convert nitrogen gas from the air to nitrogen products that plants need to grow. Nitrogen-fixing bacteria roots Decomposing bacteria

18 Health and Medicine Bacteria _______________ Bacteria ____________ Good bacteria can help harmful bacteria from making your sick. ________________ - purified and made into medicine for people that cannot make their own. Help to digest food Make vitamins Insulin-making bacteria

19 Protists ___________ - eukaryotes that cannot be classifies as animals, plants, or fungi All protists live in _____ surroundings. Animal-like protists - ________ are __________ - other feeders. Protozoans are __________ - one celled Protozoans are classified into 4 groups based on the way they ________ and ________ Protists moist heterotrophs protozoans unicellular movelive

20 Protozoans with Pseudopods ________ - sarcodines that live in either water or soil. __________ - move and feed by forming pseudopods. Pseudopod means “__________” – temporary bulges in the cell Pseuodopds move when the _______ flows in one direction and the rest of the organism follows amoeba Sarcodines False foot cytoplasm


22 Pseudopds Sarcodines use pseudopds to __________. The pseudopds are extended on both sides of the food particle until the pseudopods join together and the particle is trapped. _______________ - a structure that collects extra water that is taken into the cells of protozoans that live in fresh water such as _______ - the water is then expelled so that the amoeba will not burst. Trap food Contractile vacuole amoeba

23 Protozoans with Cilia ____ - hair like projections from cells that move in a wavelike motion. _______ use cilia to _____ and obtain _____. __________ - ciliates that are complex – two _____________ and more than one _______ Paramecium reproduce __________ by ___________or ___________ cilia ciliates movefood paramecium Contractile vacuolesnucleus asexually Binary fissionconjugation


25 Protozoans with Flagella Protists that use long, whip-like structures to move - _______ Some _________ live inside of the bodies of other organisms. The relationship where one organism is helped is called ________. (ex. Flagellate that lives inside of the intestine of termites) The relationship where both organisms are benefited is called ________ - a type of _________ flagella protozoans symbiosis mutualism symbiosis

26 Protozoans that are Parasites

27 Plantlike Protists Plantlike protists are called _____. Algea are __________. Algea are _________ and / or ____________ _______ are groups of unicellular organisms that live together – some cells in the colony are specialized for certain functions such as ____________ Some algea are also __________ algae autotrophs Food sourcesOxygen producers colonies multicellular reproduction

28 Diatoms ________ are unicellular protists with glasslike cell walls. Diatoms are a _________ for ___________organisms in waters – diatoms either float or attach to objects in shallow waters. Diatoms move by oozing chemicals from their cell walls and then gliding in the slime. Diatoms Food source heterotrophic

29 Dinoflagellates _____________ - unicellular algea surrounded by stiff plates Dinoflagellates have two _______ that are held in between their plates. Dinoflagellates whirl through the water with their flagella and some are ______________. Found on the surface of _______ waters dinoflagellates flagella Glow in the dark ocean

30 Euglenoids ________ are green unicellular algea that are found in fresh water. Euglenoids have one animal-like characteristic – they can be ___________ when sunlight is not available. ________- a common euglenoid that has a long whip-like flagellum that helps it to move.. _______ - helps the euglena to find light sources – valuable for autotrophs. Euglenoids heterotrophic euglena eyespot

31 Red Algae Almost all red algae are __________ Red _________ absorbs small amounts of light that is able to reach deep below the oceans surface. Red algae is used by humans in products such as _________, _________, and other nutrient rich foods in Asia. multicellular pigment Ice creamconditioner

32 Green Algae Green algae contain ____________ and are very diverse. Green algae can be _________, form _________, or be multicellular. Live in either ____________ or __________. Green algae and plants share the same type of ___________ There is a debate over whether green algae belongs in the ______ kingdom. Green pigment unicellular colonies Fresh waterSalt water chlorophyll plant

33 Brown Algae ____________ are brown algae. Brown algae contain ________, ________, _________, and _______ pigments. Cool, rocky waters Brown algae can form underwater _____ and provide valuable habitat for underwater creatures. Some humans eat brown algae and use it in products such as thickeners in foods. Sea weeds browngreen yellow orange forests

34 Fungi-like Protists Third group of protists (animal-like and plant-like protists) Fungus-like protists are _________, __________, and _________________. Three types of fungus-like protists include: _________ - forest floors, moist shady places __________ - decomposers of dead aquatic organisms, parasites of fish and other animals ___________ - parasites of many food crops heterotrophshave cell walls Use spores to reproduce Slime molds Water molds Downy mildews

35 Fungi Characteristics of fungi: – _________ - organism whose cell contains a nucleii – ____________ - other feeder – _____________ – ________________ – _________________________ eukaryotes heterotrophs Absorb their food Reproduce by spores Need moist, warm places to grow

36 Cell structure Fungi can be either _________ or ___________ The cells of all fungi are surrounded by a _______ All fungi, except for yeast, have _____ - branching thread-like tubes Hyphae are useful in the process of ____________ unicellularmulticellular Cell wall hyphae Food absorption

37 Obtaining Food First the fungi grow the _______ into the food source – ex. Fungi on dead trees Next, the hyphae release a chemical into the food source to help break the food down Then the hyphae ______ the food that has been broken down by the digestive chemicals that were released hyphae absorb

38 Reproduction Fungi reproduce by _____ - asexual and sexual Fungi make spores _______ - cells at the tips of the _______reproduce to form _______ Yeast is an exception – yeast cells reproduce through _______ - similar to a bud growing on a tree branch – no spores are formed. _____________ - the hyphae of two fungi grow together and the genetic material is exchanged. spores asexually hyphaespores budding Sexual reproduction

39 Role of Fungi in Nature 1. _____________ 2. _________________ - decomposers 3.________________ - penicillan 4. _______________ - parasites on plants, Dutch elm disease, corn smut, wheat rust, athlete’s foot, ringworm ______ - fungal and bacterial relationship – “pioneer” organisms. Foods for people Environmental Recycling Disease fighting fungi Disease Causing Fungus Lichens


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