Lec 10- heterotrophs

Question 1

heterotrophy diversity

Answer 1

found across all organismal groups

Question 2

herbivores

Answer 2

eats plants

Question 3

carnivores

Answer 3

eats animals

Question 4

detritivores

Answer 4

eat nonliving (dead) organic matter

Question 5

What is food economics

Answer 5

the balance between ease of getting food and the quality of food

Question 6

Ecological stoich

Answer 6

elements relationships in food
- relative abundance of C and N varies
- dictates what and how each type of heterotroph eats

Question 7

plant stoich

Answer 7

high C:N ratio
- C used to build up structure and for photosynthesis
C>N

Question 8

animals, fungi and bacteria stoich

Answer 8

low C:N ratio
less C needed
N>C

Question 9

what 5 elements make 93-97% of biomass of plants, animals, etc?

Answer 9

C
O
N
P
H

Question 10

carbon fxn

Answer 10

structure

Question 11

oxygen fxn

Answer 11

part of water molecules

Question 12

hydrogen fxn

Answer 12

part of water molecules

Question 13

nitrogen fxn

Answer 13

part of amino and nucleic acids

Question 14

phosphorus fxn

Answer 14

essential for cellular processes- ATP energy transfer

Question 15

herbivory- food stoich

Answer 15

easy to get food- abundant
low quality food- rich in C but poor in N- difficult to digest

Question 16

herbivory food

Answer 16

substantial nutritional chem challenges
- low N, high C
- cellulose and lignin strenthen tissue but increase C:N ratio = difficult to ingest and digest
- overcome plant physical and chemical defenses
physical: spines/thorns
chemical: toxins/digesting reducing compounds
- plants are poor food and animals must generally consume large amounts of food

Question 17

koala diet

Answer 17

eucalyptus
- long digesting organs
- gut microbes
- long sleep

Question 18

elephants diet

Answer 18

large amounts of food
10% of food to obtain nutrients

Question 19

porcupines

Answer 19

defense strategies against predators (quills)

Question 20

carnivory stoich

Answer 20

hard to get food but high quality of food
- nutritionally rich prey
- little variation in C:N ratio: prey available and have varied diet
- selection on nutritional requirements less strong, selection stronger on ability and efficiency of capturing and consuming diff preys
- adaptions to hunt effectively

Question 21

detritivory stoich

Answer 21

easy to access but high and low quality

Question 22

difference between detritivory and decomposition

Answer 22

both contribute to decomp and nutrient recycling
- detritivores = ingest and digest dead matter via internal processes (sea cucs)
- decomposers = directly absorb nutrients through chemical and bio processes (fungi)

Question 23

detritivory

Answer 23

feed on nonliving organic matter
dominant food source is dead plant matter
dead plants rich in C and energy but poor in N
- N limiting to living plants
Nitrogen Use Efficiency in plants to reabsorb N before dropping leaves
- fresh detritus may have physical and chemical defenses present
- not limited by food
- abiotic and chemical composition more direct impacts (soil moisture)

Question 24

mixotrophy

Answer 24

exploit more than one C source

Question 25

omnivores

Answer 25

gain energy from plants and animals

Question 26

mixotrophs

Answer 26

gain energy from photosynthesis (inorganic) and from consuming organic material

Question 27

saprophytes

Answer 27

feed on dead matter
pinesap

Question 28

parasites

Answer 28

feed on living plant host
dodder

Question 29

epiphytes

Answer 29

grow on other plants
- DOES NOT parasitize on them
epiphytic fern

Question 30

insectivorous plants

Answer 30

additional nutrients from trapped insects
- venus fly trap

Question 31

functional response

Answer 31

relationship b/w food availability and feeding rate
- relationship b/w food density and food intake levels off

Question 32

what influences feeding rate?

Answer 32

1. animals can only eat so much in mouth
2. time to digest (make room for more)
3. time to find food (easier for herb)
4. time to handle/process food (herb needs more time)
5. safer to hide than eat

Question 33

functional response curve (1)

Answer 33

feeding rate increases linearly up to incipient limiting concentration
- due to quick processing
ILC- feeding rate levels off abruptly, max feeding rate. prey density at which food intake levels off into aymptote
- zooplankton
- rare kind of curve

Question 34

functional response curve (2)

Answer 34

feeding rate increases linearly at low concentrate at slow rate at moderate concentrations then levels off at high concentrations
- limited by search and low densities
- at hgiher densities then food is widely available
- more common
- large animals (moose)

Question 35

functional response curve (3)

Answer 35

s-shaped
low at low food densities
increases at intermediate food densities and then levels off at high food densities
- juveniles

Question 36

optimal foraging theory

Answer 36

max or min some factors to optimize feeding process
- what
- where
- when
- costs vs benefits
- allocated energy
- approach to understand behavior

Question 37

marginal value theorem

Answer 37

where and when to eat
how long should animal forage in food patch b/f moving to a new location?
- graph
slope = energy gain per unit time
red line = total energy gained by organism as it forages in a patch
- optimal time to spend in a patch is one that maximizes energy gain per unit time across a landscape of patches

Question 38

diet composition - what to eat

Answer 38

rate of energy intake or predator feeding on ONE prey

E/T = Ne1E1- Cs/ 1 + Ne1H1
Ne1 = # of prey per unit time
Cs = energy expended searching
H1 = handling time

Question 39

energy predictions

Answer 39

if 1 prey was not enough they add a second prey so 2 prey E/T&raquo_space; 1 E/T

if 1 pray enough then 1 prey E/T > 2 prey E/T

Question 40

Bluegill sunfish

Answer 40

support the optimal foraging theory
- size distribution of prey in natural habitat
- predicted intake of prey by size (big prey = more food per unit effort)
- actual intake of prey by size, measured in natural habitat