Bio Exam 2

Characteristics of life

organization, energy processing, responsiveness, evolve, growth, reproduction

Viruses do not grow or reproduce their own ________

cells

all of an organism's genetic material

Genome

Does a virus have a genome?

Yes

A Virus can be _________, single stranded _______, or double stranded __________

-DNA

-RNA

-RNA

Smallest viruses are _______mm in diameter and are smaller than __________

-20mm

-ribosomes

A virus can only reproduce within what kind of cell?

a host cell

Viruses are infectious particles, they are not ________

cells

Viruses sometimes have a __________ envelope

membranous

Outer protein coat of a virus

Capsid

protein subunits that make up capsids

capsomeres

protein to bind to host

recognition spike

The severity of a disease or poison.

The ability to damage the host.

Virulence

Virus that infects bacterium

Bacteriophage

Once bacterium is infected, it undergoes one of two life cycles:

Lytic and lysogenic cycle

Every bacteriophage can undergo the ________ cycle

Lytic

Reproductive cycle that ends in death of the host cell

lytic cycle

A phage that reproduces only by a lytic cycle.

virulent phage

replicates phage genome, doesn't kill cell.

lysogenic cycle

viral DNA copied in host cell

Prophage

dsDNA

double stranded DNA

ssDNA

single stranded DNA

ssRNA, some serve as mRNA

single stranded RNA

dsRNA

double stranded RNA

some ssRNA serves as a template for

RNA and DNA synthesis

A virus that causes infections in humans, such as herpes, adenovirus, papillomavirus, smallpox, and cowpox.

-dsDNA

Herpesvirus

-ssDNA

-fifth disease

-slapped cheek disease

Parvovirus

-dsDNA

-Colorado Tick Fever Virus

rotavirus

-Single Strand RNA

-No cure

-79% vax rate

Poliovirus

Who developed the first successful polio vaccine?

Jonas Salk, he did not patent it

created the oral polio vaccine

Albert Sagan

Who created the live polio vaccine, rabies, and was blamed for AIDS but then cleared of it

Hilary Koprowski

RNA genome is converted to DNA prior to viral reproduction

Retrovirsus

-ssRNA template for DNA synthesis

-HIV, AIDs, and RNA tumor viruses

Retrovirus

How do new viruses emerge?

mutation, interspecies contact, spread from isolated areas

What is a prion?

-an infectious protein that is incurable.

-Mad Cow disease, Creutzfeldt Jakob disease

-Kuru (disease caused by cannibalism)

What are small, circular RNA molecules?

-Viroid which is a disease in plants.

-They do not encode proteins, but can replicate by using host enzymes.

Consists of the skin, mucous membranes, hair, and nail

integumentary system

Plasma, red blood cells, white blood cells, platelets.

Blood system

Composed of a network of vessels, ducts, nodes, and organs. Provides defense against infection.

lymphatic system

_________ __________ are your first line of defense against infections.

External barriers

What are the external barriers?

Skin, hair, mucous membranes, and gastric juice

produced in red bone marrow and lymphatic tissue that fight foreign substances

white blood cells

ingest and destroy foreign substances

phagocytic cells

What are the two types of white blood cells?

innate cells and lymphocytes

________ cells are premade and ready to attach

innate

_____________ are produced after contact with a specific invader.

Lymphocytes

A type of white blood cell that are the first to respond to infection but die quickly

Neutrophils

-Developed from monocytes

-leave blood and enter tissues

-can ingest more than neutrophils

-protects lymph

Macrophages

made in red bone marrow

- leave blood and enter infected tissues

- can release histamine

Basophils

-produced in red bone marrow

-release chemicals to reduce inflammation

Eosinophils

-Develop into B & T cells

-Produce immune response

Lymphocytes

•Almost immediately after damage, __________ form a sticky plug that can seal a minor break.

platelets

•Molecules of ________ cross-link to form a clot which, if on your skin ,is called a scab.

fibrin

•involves chemical and cells due to injury

•signaled by presence of foreign substance

•stimulates release of chemical mediators

inflammatory response

The inflammatory response is a __________ ___________ against tissue damage

nonspecific defense

•The cells of a damaged tissue release chemicals that trigger the _________ _________

inflammatory response.

•White blood cells called __________ engulf and destroy bacteria.

phagocytes

If an invader enters the body, the ______________ system can provide protection

complement

•Proteins of the ____________ system assemble on the ___________ of an invading bacterial cell, forming a hole.

-This causes the cell to swell and burst.

-complement

-surface

•Immediate, rapid response

•Physical barriers or inflammation

•Generalized response, nonspecific

Innate defense

•Slower response (a few days)

•Invader recognition

•Repeated exposure to molecules will cause increased responses

Adaptive defense

•Exposure to an ____________, a molecule that elicits an immune response, starts your adaptive defenses.

-antigen

a lymphocyte able to bind to certain tumor cells and virus-infected cells without the stimulation of antigens, and kill them by the insertion of granules containing perforin.

natural killer cells

B cell activation

Antigens bind to lymphocytes, then produces antibodies.

Once an antigen activates a particular lymphocyte, it multiplies creating army of cells when needed.

Clonal selection

lymphocytes that stimulate production of other immune cells

helper T-cells

•After a primary immune response, your body produces _______ cells.

memory

If the same invader is encountered again, memory cells instigate a __________ ________ __________ that neutralizes the invader before it causes illness

secondary immune response

Does stress reduce immune responses?

Yes

•Problems can arise when the immune response is _______ ______

too strong

e.g. allergies, autoimmune diseases, and organ rejection

•Harmless substance enters the body and B cells make _________ to it

B cells

B cells and T cells

2 types of lymphocytes

T cells

cell-mediated immunity

B cells

produce antibodies

Cells that release chemicals (such as histamine) that promote inflammation.

mast cells

Both limbs of lymphocyte system are missing or defective; no adaptive immune response

Severe Combined Immunodeficiency (SCID)

immunodeficiency diseases

a condition that weakens the immune system

Small, open-ended lymph vessels that act like drain pipes which picks up lymph at tissues throughout the body

Lymphatic capillaries

large vessels with valves, which collect and carry lymph to lymph nodes

lymphatic vessels

receives lymph from the right upper part of the body

right lymphatic duct

masses of lymphatic tissue in the back of the oropharynx

tonsils

small oval clumps of lymphatic tissue located at grouped intervals along lymphatic vessels

lymph nodes

spleen

Organ near the stomach that produces, stores, and eliminates blood cells

located in the mediastinal cavity anterior to and above the heart; secretes thymosin

thymus gland

disease that can be passed between animals and humans

zoonotic disease

Zoonoses have reservoirs, what does this mean?

Reservoirs are a natural disease agent. Zoonoses' can exist in other species, we cannot eradicate a disease without killing the whole species.

___________ can evolve in a host species reservoir or in other infected species

Zoonoses

Disease reservoir

A natural source of disease agent.

causes of zoonoses

•Contamination (water or food)

•Insect vectors

•Wildlife, pets, animal attacks

•Farming, animal husbandry

•Bushmeat

•Deforestation and habitat degradation

•Climate change

•Secondary transmission

a physical or biological factor that alters the structure and species composition of the community. When this happens, diseases may be spread to humans.

ecological disturbance

human to human disease spread

contagion

Can humans and animals transfer zoonoses between each other?

Yes

Virus overcomes several barriers to become feasible in another species

Spillover

an epidemic that is geographically widespread

Pandemic

a rare emerging zoonotic disease that causes severe and often fatal disease in both infected horses and humans

Hendra virus

-fungus

can spread in environment easily

-animal to person

person to person

directly from environment

Ringworm

-breakbone fever

-ssRNA virus

Dengue

-SARS-COV2

-very common

-unknown initial reservoir

-rapid spread though respiratory droplets

Covid-19

-virus with mutated genetic sequence

-few or many mutations

-expect new variants to rise in prevalence when vaccines effective

covid variants