Unit 1 Bio
What are viruses?
- non living organisim lives as a parasite to another living organisim
- nither prokaryotic or eukaryotic
- they affect other living things
- Not every virus is considerd a disease
Ex : cold virus affects the respirtory system, ravies infects the nervous
Characteristics of Viruses
- cannot live independantly
- need a living host to reproduce, if not they are dormat
- dont contrain any cytoplasm or membrane bound organelles
- dont undergo indepedant movement, dont metabolize
- contain DNA
Virus Classification
- Can be classified by size and shape of the capsid
- can be grouped according to the types of disease they cause
- largest and most complex viruses are the ones that attack bacteria
Viral Reporduction
- cannot reproduce on their own
- remain dormant until they enter and hijack the reproductive machinery of lving cells
- they can reporduce by either going lytic or lysogenetic cycle
Lytic Cycle
1. (Attachment and entry) : protien on the surface of the virus bind to protien receptors on the surface of the host cells membrane
2. (Systhesis) : The host cell makes more virral DNA or RNA and protiens
3. (Assembly) : New virsusess are assembled
4. (Lysis) : the host cell breaks open and releases new viral protiens
Lysogentic Cycle
1. Virus genetic material enters the cell and becomes partt of the host cells chromosome
2. referred to as a provirus, can invade a cell but not infect it, as the cell divides so does the virus
3. Provirus wont activate till later, and when it does the lytic cycle continues
Vaccines and Antibodies
- antibodies build up to fight off viruses that infect someone
- either the antibodies kill off the virus or the virus takes over and kills the host
- vaccine are antibodies that are injected, to prepare your body so its ready to fight off a certain type of virus
Cornaviruse
- An RNA virus that has a round protien coat around it that looks like a crown
- can cause mild repitory illnesses like colds, pneumonias and brochitis
- incubation period is abt 14 days
What are Prions
- Prion : a infection particle that causes damange to nerve cell in the brain and appeart to consist of protien, yet lack DNA and RNA
- Affect mammals in the brain or other neural tissue and currrectly no treatments are fatal.
- Ex: (CJD), (BSE)
Common characteristics of Archaebacteria, and Eubacteria
- These are all types of bacteria
- unicellular and prokaryotic
- smallest organisim on earth
- no memrame bound organelles
- contain a single chromosome
- reproduce asexually by binary fusion
Comparing Morphology
- Spherical (cocci)
- Rod Shaped (baccili)
- Sirral (spirilla)
Eubacteria
- found in regular environments
- the ones that can cause illness in humans
- make foods and products
Shapes of Bacteria
Cocci : can occur in singles, doubles and chairs, (streptococcus, strepylococcus)
Bacilli : found in singles, doubles, or chains (E.coli)
Spirilla : (pallidum - casuses STDs)
Archaebacteria
- Primitive live in environments where other organisim cannot survive
- most produce methane gas
- most live in anerobic conditions
Three major groups of archaebacteria
Extreme Acidophiles : (very acidic conditions)
Extreme Thermophile : (very hot conditions, valocones)
Extreme halophiles : (very salty conditions, like deep oceans)
Reproduction and Growth
- all bacteria reproduce asexually by binary fusion
- single strand of bacteria replicated, resulting in identical genetic material being transferred to each new cell
- then bacteria produces a septum and spits into 2 identical cells
- when conditions are not ideal some bacteria will reporduce sexually by conjugation
- 2 bacteria cells connecty to eachother by a pilus, DNA is transferred from donor to recipient
- Recombination of DNA occurs in recipient, altering its set of chromosomes
Endospores
- resting or domant bacterial cells when conditions become extreamly unflavouirble
- thickhend walls forms around genetic material cyctyoplasm,therefore DNA styas intact even if cell disintergrates
- when flavourable conditions return, the wall breaks down and bacteria emerges
Beneficial effects of bacteria
- act as decomposers for plants and animals
- produce foods like togurt, cheese, kimchi
- sysnthesis of vitamins un humans
- produce latic acid
Harmful causes of bacteria
- many cause disease
- sheer numbers of bacteria place tremendous burned on hosts tissue
- some bacteria destroy cells and tisstues
- some produce deadly toxins
bacterial diseases treament
- Bodys own immune system
- Sterilization
- Antiseptics
- Extermination of animals
- Antibiotics
What are the 3 kingdoms we are studying
Plantae, Protista, Fungi
Kingdom Protista:
- Found in many places
- some are terrestrial
- mostly aquatic
- contain chloroplasts
- most are single celled
- some are muilticellular
- some are both autotrophs or heterotrophs, or both
- reproduce sexually and A-sexually
Kingdom Fungi:
- Similar to plants, cant preform photosynthesis
- heterotrophs
- muilticellular
- many nuclei per cell
- no roots, no seeds
- cell walls made of cellulose
- reproduce sexually and a-sexually
- symbiotic relationships with certain plants
Ex: yeast, moulds, muchrooms
Importance of Fungi:
- Act as decomposes in ecosys
- Used in foods; bread
- Used in Antibiotics
Kingdom Plantae:
- Cell walls contain cellulose
- All are muilticellular
- All are autotrophs
- Most reproduce both ways
- Have chloroplats
Ex: Mosses, Ferns, seed plants.
Classification of the Animal Kingdom
- All animals belong to the domain Eukarya and Animilia with a total of 35 phyla
Ex: homo sapien
What is a phylum Chordata
- have a notochord and a veterbrate (internal skeleton of bone or cartilidge)
Characteristics of Kingdom Animilia:
- Heterotrophic
- have the power of motion or locomotion by means of muscle fibres
- Muiliticellular, have specelized cells that form tissues and organs, cells dont have cell walls
- Have a life cycle in which the adult is diploid
- Reproduce sexually
Characteristics used to classify Animals
- if it has a backbone or not
- numbers of body layers
- symetry and body planes
Invertebrates:
Animals with no backbone (95%)
Vertebrates:
Animals with a backbone (5%)
Levels of Organization
- Classified on their structures, tissues and organ systems
- All animals have different oragan systems
Number of Body Layers
- All animals other than sponges and those within Phylum Cnidaria have 3 layers
What are the 3 layers
- Ectoderm : Outer Layer
- Mesoderm : Middle layer
- Endoerm : Inner layer
Symmetry and the Body Plans
- Diff animals have different arangement of their organ system
- Some animals have irregular body plan and are asymmetrical
Radial Symmetry
- body plan that can be divided along any plane and be symmetrical
Bilateral Symmetry
- Body plan that can only be divided along just one plane,
- Equal halves.
Body Cavities
- Animals have their organ system suspended in a fluid body
Coelmates:
include worms, molluse, insects
Acoelmates
include corals, jelly fish, flatworms
Segmentation:
division of muilticellular bodies into series of reptetive parts
Movement
- Many animals developed nerve muslce tissues which allowed them the ability to move from place to place - locomotion
- Others are sessile
Reproduction
- Most animals repoduce sexually, using genetic reproduction
External Fertilization:
the gametes join outside of the body
Ex: Fish
Internal Fertilization
gametes join inside the body
Ex: mammals, birds