Microbes

Question 1

Microbes

Answer 1

Living organisms and nonliving entities, microscopic size, ubiquitous (found everywhere)

Question 2

Roles of Microbes

Answer 2

Affect human health e.g more microbes live in out body than there are cells
Essential for life on this planet e.g produce oxygen via photosynthesis
Decomposition of dead organisms and their waste products (Saprophytes)
Antibiotic production (natural)
Food production e.g yoghurt
Genetic engineering e.g compounds like insulin

Question 3

Categories of microbes

Answer 3

Acellular

Cellular

Question 4

Types of cellular microbes

Answer 4

Prokaryotes

Question 5

Types of acellular microbes

Answer 5

Viruses

Prions

Question 6

Types of prokayotes

Answer 6

Bacteria

Archea

Question 7

Types of Eukaryotes

Answer 7

Fungi
Yeast
Protozoa

Question 8

Pathogens and percentage of organisms that are pathogens

Answer 8

Disease causing micro-organisms

3% of microbes

Question 9

Non pathogens

Answer 9

Microbes that do not cause disease

Question 10

Opportunistic pathogens

Answer 10

Microbes that usually harmless but can cause disease if they colonise the wrong part of the body or when we are vulnerable to infection e.g Candida Albicans (thrush)

Question 11

Infectious disease

Answer 11

Disease caused by pathogenic microorganisms (e.g bacteria, viruses, parasites or fungi)
Spread directly or indirectly from one person to another

Question 12

Acellular microbes

Answer 12

Microbes that need to invade other cells to replicate or perform physiological functions
(energy generation or protein synthesis)
Not considered to be alive

Question 13

Virus

Answer 13

Made of a genome of either DNA or RNA and a protein coat called a capsid made of proteins called capsomeres

Question 14

Properties of Viruses

Answer 14

Can not replicate on their own (need host cell)
Have either DNA or RNA not both
Do not divide by binary fission, mitosis or meiosis
Can not produce their own energy
Can not produce their own proteins

Question 15

Classifying Viruses

Answer 15

Type of genetic material
Shape of capsid
Number of Capsomeres
Presence or absence of an envelope
Type of host it infects
Types of disease it produces
Its target cell
Its antigenic properties

Question 16

Bacteriophages

Answer 16

Viruses that infect bacteria

Question 17

Animal Viruses

Answer 17

Viruses taht infect animals

Question 18

Viroids

Answer 18

Infectious particles that consist of short pieces of RNA that interfere with the function of plant cells

Question 19

Prions

Answer 19

Infectious particles that consists of small proteins that can cause neurological conditions in humans and animals

Question 20

Prokaryotes features

Answer 20

Free floating DNA in cytoplasm
Have a complex cell wall consisting of peptidoglycan
No internal membranes
Ribosomes smaller and less dense then eukaryotic cells
Single celled

Question 21

Components of Prokaryotes

Answer 21

Plasma membrane
Chromosome
Plasmid
Cytoplasm
Cell wall

Question 22

Plasma membrane

Answer 22

Encloses all the contents of the cell

Composed of phospholipids and proteins

Question 23

Chromosomes

Answer 23

Single, long, circular DNA molecule
Highly coiled around itself
In cell nucleus

Question 24

Plasmid

Answer 24

Small circular pieces of DNA that are not part of the main chromosome
Can have none, one or many plasmids
Exchange of plasmids from one bacterium to another can result in development of multi-drug resistant strains of bacteria

Question 25

Cytoplasm

Answer 25

A semi liquid substance that contains water ,salts, enzymes, nutrients, proteins, carbohydrates and lipids

Question 26

Cell wall

Answer 26

Rigid structure on the outside of the plasma membrane Provides rigidity, strength and protection for the cell Major component is a complex molecule (peptidoglycan) which is only found in bacteria

Question 27

Gram positive bacteria

Answer 27

Think layer of peptidoglycan on the outside of the surface of the cell wall

Question 28

Gram negative bacteria

Answer 28

Have a thinner layer of peptidoglycan but it is sandwiched between layers of other complex molecules

Question 29

Glycocalyx

Answer 29

Layer of slimy, gelatinous material excreted on the outside of the cell wall

Question 30

Types of glycocalyx in bacteria

Answer 30

Capsules | Slime layer

Question 31

Capsule

Answer 31

A highly organised layer, firmly attached to the outside of the cell wall Helps prevent bacteria from being phagocytised by the cells of you immune system (live longer)

Question 32

Slime layer

Answer 32

A not highly organised layer and it is not firmly attached t the cell wall Helps bacteria move along surfaces

Question 33

External structures of bacteria

Answer 33

Glycocalyx Flagella Fimbriae (pili)

Question 34

Flagella

Answer 34

Threadlike appendages that function to move bacteria around | Possess flagella = motile

Question 35

Fimbriae (pili)

Answer 35

Hair like structures that are observed on the outside surface of bacteria

Question 36

Roles of different types of Fimbriae (pili)

Answer 36

Allow attachment of bacteria to surfaces | Allows transfer of genetic material

Question 37

Endospores

Answer 37

Thick walled structures that contain a copy of the chromosomes and some of the cytoplasm Allows bacteria to survive in adverse conditions When endospores land in a suitable environment it germinates to produces new bacteria

Question 38

Binary Fission

Answer 38

Prokaryotic cells way of reproducing whereby a parent cell splits into 2 halves producing 2 new cells

Question 39

Features of Eukaryotes

Answer 39

DNA contained in Nucleus Eukaryotes of animals do not possess a cell wall Eukaryotes of plants have simple cell wall consisting of cellulose Have organelles Ribosomes are larger and denser than prokaryotes Single celled of multicellular

Question 40

Types of Eukaryotes

Answer 40

Fungi - Yeasts, moulds and mushrooms Algae Kingdom protista (protozoa, lichens, slime mounds)

Question 41

Fungi and two subgroups of fungi

Answer 41

Includes yeasts, mould and mushrooms Found almost everywhere Saprophytic fungi - Lives on organic matter in water and soil Parasitic fungi - lives on/in animals and plants

Question 42

Algae

Answer 42

Photosynthetic | Range in size from small, unicellular microscopic organisms through to large multicellular organisms

Question 43

Kingdom protista eukaryotes

Answer 43

Protozoa Lichens Slime moulds

Question 44

Protozoa

Answer 44

Most are unicellular Found in soil and water More like animal cells than plant cells

Question 45

Life cycle of protozoa

Answer 45

Trophozoite stage - the motile, feeding, dividing stage | Cyst stage - non motile, dormant, survival stage

Question 46

Groups of protozoa

Answer 46

Amoebas Ciliates Flagellates Non-motile protozoa (Sporozoites)

Question 47

Amoebas

Answer 47

Move by extending portion of their cell membrane and cytoplasm in structure (Pseudopodia)

Question 48

Ciliates

Answer 48

Move using a large number of hair like cilia on the outside surface of the cell

Question 49

Flagellates

Answer 49

Move using a whip like flagella

Question 50

Non motile protozoa (Sporozoites)

Answer 50

Do not contain pseudopodia, cilia or flagella