L.38- Fungi

_ commonly inhabit soil or dead plant matter

fungi

large number of fungi are _ pathogens

plant

fungi are primary agents and major contributors in global _ cycle and bio-degradation of dead plants, animals, and wood debris

carbon

without _, earth would be buried in several feet of debris and life on this planet would disappear

fungi

degradation processes by fungi are _

slow

2 forms of fungi related to disease: _ (normally grow as single cells) or _ (form branching filaments that intertwine to form visible masses)

yeast, mold

fungi in disease have a 2-phase life cycle: _ and _ phase

growth, reproductive

fungi reproduce _ or _

asexually, sexually

3 overall mechanisms of fungal disease

inappropriate immune responses, toxin production, mycoses

most common and most dangerous type of fungal disease

mycoses

fungal infections can be especially serious in individuals with impaired _ system

immune

systemic fungal infections have emerged as important causes of morbidity and mortality in _ patients

immunocompromised

genital and intestinal candidiasis also associated with use of _

antibiotics

qualitative and quantitative aspects of candidiasis is dependent on _ status of the individual and route of _

immune, transmission

fungi grow easily in _ and _ of houses where fungi emit toxic gases and cause mold allergies

basements, bathrooms

_ species are thermally dimorphic fungi that grow as brownish mycleium externally and as yeast at 37 degrees C

histoplasma

superficial and subcutaneous mycoses treatable with _ antifungal agents

topical

molecular and cellular biology of fungi are similar to that of _ hosts

mammalian

immunologically intact mammals are highly resistant to fungal diseases such that human systemic fungi are considered _

opportunistic

mammals are remarkably _ to fungal diseases

resistant

resistance of mammals to mycotic diseases is a combination of vertebrate _ and _

immune system, elevated body temperatures

endothermy and homeothermy contribute to mammalian resistance to mycosis by creating _ that inhibits fungal species

thermal exclusionary zone

experimental evidence for synergy of _ and _ in mammalian resistance to mycotic diseases

temperature, immunity

resistance of mammals to fungal diseases is a sharp contrast to _ of vertebrates like amphibians (ectotherms)

vulnerability

reptiles (ectotherms) require _ of daily mammalian energy needs

1/2

repitilian development is _ than mammals' and requires _ parental involvement

faster, less

_ replaced reptiles as dominant land forms after catastrophe known as the K-T boundary

mammals

proof of _ was layer of reddish clay between 2 layers of limestone, each representing cretaceous and tertiary periods

K-T boundary

hypothesis for demise of dinosaurs is that asteroid impact 65 million years ago contributed to disrupting cretaceous _

ecosystem

ecological changes contributed to end of the "age of reptiles" by introducing new stressors to _ including fungi "selected" by lower temperatures that followed asteroid strike

immune systems

asteroid strike of K-T event likely drove massive _

deforestation

altered _ after K-T event disrupted food sources and changed climate (significant cooling of Earth caused by dust clouds)

ecosystem

cooling of earth following K-T event led to massive _ as earth became "global compost" for destroyed organic matter

fungal bloom

likelihood that pathogenic fungi existed at K-T boundary is enhanced by finding that potential for _ arose independently several times in evolution

pathogenicity

dark skies and cool temperatures after K-T event reduced ability of _ creatuers to induce fevers by insolation (necessary activity for protection against fungal diseases in reptiles)

ectothermic

_ unable to induce behavioral fevers and in weakened immune states due to environmental stress were at severe disadvantage relative to mammals with innate exclusionary zones for fungal growth

ectotherms

higher global temperatures could select for more thermally _ fungi

tolerant

systemic _ are deep-seated, potentially life-threatening diseases caused by fungi that are difficult to treat

mycoses

majority of fungi are _ to humans

harmless

fungi grow in nature as _ on dead organic matter and are therefore important for _ cycle

saphrocytes, carbon

fungi are medically important as agents of _ and producing new _

disease, therapeutics

many pathogenic fungi are _ and can exist as single cell yeast or in filamentous form regulated by environmental factors like _ and _ levels

dimorphic, temperature, moisture

re-exposure to same fungi may cause _ reactions

allergic

large and diverse group of fungal exotoxins

mycotoxins

_ grow and get transmitted from improperly stored dry foods and can be toxic and carcinogenic

alfatoxins

treatment of _ mycoses is difficult because of issues with host toxicity with existing drugs

systemic

common superficial pathogenic fungi that becomes more invasive near end of life

candida albicans

common source of inhalational diseases in Midwestern region of the U.S.

histoplasmas

fungi are among the _ and _ living organisms on earth

largest, longest

aftermath of K-T event selected for _ mammals over _ animals like reptiles

endothermic, ectothermic

_ hypothesis states that K-T event selected for animals resistant to fungi that proliferated in lower temperatures of earth after K-T event

fungal filter

fungi related to disease generally have a 2-phase life cycle, consisting of growth and reproductive phases. Which is most true concerning the 2 phases?

during growth phase, molds develop hyphae

what is the most likely reason that a drug to treat athlete's foot is toxic to humans is not approved by FDA for widespread use?

drug targets essential signal transduction pathway that is present in humans as well as fungal species in question

_ mycoses are where fungi only infect the superficial layer of skin, hair, or nails

superficial

_ mycoses are infections of deeper layers of the skin

subcutaneous

_ mycoses are caused by pathogenic fungi that infect and grow in internal organs of the body

systemic

HIV patients often suffer from fungal infections because they are highly _ through the gradual loss of CD4 cells

immunosuppressed

the use of _ shifts the microbiome of the HIV patient resulting in increased opportunities for fungal pathogens to colonize and disseminate

antibiotics