7.1 paratism and pathogens

Question 1

what is symbiosis?

Answer 1

the intimate and protracted association between two or more organisms of different species
-this does not specify whether the relationship is positive, negative or benign
-coevolution is evident in these interactions

Question 2

what is parasitism?

Answer 2

a close association between two species is beneficial to one (the parasite) and harmful to the other (the host)
-parasites increased their fitness by exploiting host organisms for food, habitat and dispersal
-parasites generally do not kill their hosts, but the host may suffer reduced fitness

Question 3

what are common traits shared by parasites?

Answer 3

1. much smaller than their hosts
2. reproduce more quickly and in greater numbers
3. highly specialized for their way of life

Question 4

what are the two types of parasites?

Answer 4

-microparasites= characterized by small size and short generation time (viruses, bacteria and protozoans)
-macroparasites= relatively large with a comparatively long generation time and usually involve intermediate hosts and carriers (invertebrates like flat worm, ticks and lice and fungi like rusts and smuts)

Question 5

what are microparasites?

Answer 5

-microparasites and their disease are often transmitted directly (influenza, smallpox, covid) or acquired from the environment (cholera, malaria)
-like bacteria, viruses, protozoans

Question 6

what is the equation for the change in number of infectious individuals in the population?

Answer 6

Question 7

what is the graph of the contagiousness and lethality of airborne viruses?

Question 8

what is the big graph of the microbe-scope?

Answer 8

Question 9

what are the symptoms of measles?

Answer 9

Question 10

Question 11

Question 12

what is the Ro of ancestorial strains and delta?

Answer 12

Question 13

what is the mortality risk for covid 19?

Answer 13

Question 14

what are examples of macroparasites?

Answer 14

-female roundworm lay eggs in the host’s gut which are expelled with the feces
-feces are dispersed to the surrounding environment, and if they are swallowed by the host of the correct species, the eggs hatch

Question 15

what is the graph of parasitism?

Answer 15

Question 16

what is the life cycle of large strongyle in horses?

Answer 16

Question 17

Question 18

what is the fecal egg counts and body condition on sable island?

Answer 18

Question 19

what are macroparasites?

Answer 19

hosts are the habitats for parasites
-ectoparasites are those that live on the host’s skin within the protective cover of feathers and hair
-endoparasites live within the host (eg; beneath the skin, bloodstream, gills of fish, mouth parts)
-plant parasites live various places in and on a plant (in and on roots, leaves, fruits, etc)

Question 20

what are parasitic plants?

Answer 20

derive some of all of their nutrition from another plant
-the modified root (haustorium) penetrates the host plant

Question 21

what are special forms of parasitism?

Answer 21

-kleptoparasitism occurs when one animal (parasite) steals the food gathered by another (host)
-brood parasitism: parasitic female birds lay eggs in the nest of a host

Question 22

how are parasites and pathogens agents of selection?

Answer 22

-parasites and pathogens can decrease reproduction and increase mortality of the host
-parasites nay function as density-dependent regulators on host populations
-selective agents of mortality