Chapter 43

Question 1

Pathogens

Answer 1

Organisms that cause disease

Question 2

Parasites

Answer 2

Feed on hosts and benefit at their expense

Question 3

Animal Responses to Preventing Pathogens and Parasites

Answer 3

1. Innate Immunity (all animals)

2. Adaptive Immunity (vertebrates only)

Question 4

Innate Immunity

Answer 4

Shared traits recognized by few receptors (*rapid)

1. Barrier defenses:
   * skin
   * mucous membranes
   * secretions
2. Internal defenses
   * phagocytic and natural killer cells
   * antimicrobial proteins
   * inflammatory responses

Question 5

Adaptive Immunity

Answer 5

Recognizes specific traits using many receptors (*slower)

1. Humoral response:
   * antibodies defend body fluids
2. Cell-mediated response:
   * cytotoxic cells defend body cells

Question 6

Land Plant Responses (2)

Answer 6

1. Hypersensitive response

2. Systemic Acquired Resistence

Question 7

Systemic Acquired Resistance (6)

Answer 7

1. Triggered by the presence of a pathogen (or herbivore)
2. Can prevent spread of infection
3. Dutch elm disease: ‘wilt’ disease
4. Fungus spread by beetle vector
5. Innate defenses overwhelmed, no antimicrobial defenses or evolutionary history with pathogen
6. Plant blocks xylem to prevent spread of fungi
   * rapidly fatal

Question 8

Preventing Predation (3)

Answer 8

1. Behavioural Defences
2. Chemical Defences
3. Physical Defences

Question 9

Behavioral Defenses (4)

Answer 9

1. herds/schools
2. hiding
3. fleeing
4. self-defence (rare)

Question 10

Chemical Defences

Answer 10

toxins, scents, etc.

Question 11

Physical Defences (3)

Answer 11

1. Quills, trichocysts, etc.
2. Colouration
3. Mimicry

Question 12

Coloration

Answer 12

1. Cryptic: hide from predators

2. Aposematic: toxins present

Question 13

Mimicry

Answer 13

1. Batesian: harmless but pretends otherwise

2. Mullerian: unpalatable and resemble eachother

Question 14

Protecting Relatives (4)

Answer 14

1. Some animals serve and protect others (altruistic)
2. Advantages = ‘inclusive fitness’
   - fitness achieved by helping close relatives
3. 3 Determinates:
   - benefit to recipient (B)
   - cost to provider (C)
   - relatedness of individuals (r)
4. Hamilton’s Rule

Question 15

Hamilton’s Rule

Answer 15

If rB>C, natural selection favours altruism

Question 16

Defend Resources (3)

Answer 16

1. Protect habitat, mates, food, etc.
2. Interspecific (between) and intraspecific (within)
3. Animals often defend territory or home-range from con-specifics to ensure access to mates and prey