Unit 04: Animal Nutrition

Question 1

What is nutrition?

Answer 1

The balance between nutrient intake and the needs of the body.

Question 2

What must diet provide?

Answer 2

1 - Chemical energy

2 - Organic molecules

Question 3

Why do we need chemical energy from diet?

Answer 3

Food stores chemical energy which is then broken down, generating ATP which fuels cellular processes.

Question 4

What are organic molecules and why do we need them?

Answer 4

“Raw” material like carbon or nitrogen which allows for biosynthesis of macromolecules (proteins, carbs lipids).

Question 5

What are essential nutrients?

Answer 5

Nutrients that animals cannot make, must be obtained from diet.

Question 6

What are the 4 classes of essential nutrients?

Answer 6

• Amino acids (complete vs incomplete proteins)
• Fatty acids ex. omega 3, 6, 9
• Vitamins (organic molecules) ex. B, C, D
• Minerals (inorganic molecules) ex. B C D

Question 7

How many amino acids can we not synthesize?

Answer 7

8/20

Question 8

What are some examples of complete and incomplete proteins?

Answer 8

Complete - meat, cheese

Incomplete - plants (variety is needed)

Question 9

What are the four stages of food processing?

Answer 9

1. Ingestion
2. Digestion
3. Absorption
4. Elimination

Question 10

What is the difference between elimination and excretion?

Answer 10

Elimination = pooping
Excretion = peeing

Question 11

What are the four feeding mechanisms used by animals?

Answer 11

• Suspension/filter feeding
• Substrate feeding
• Fluid feeding
• Bulk feeding

Question 12

Describe suspension feeding and list some animals that use this method of ingestion.

Answer 12

Sifting small food from water

Clams, baleen whales

Question 13

Describe substrate feeding and list some animals that use this method of ingestion.

Answer 13

Living in/on food source

Maggots, caterpillars

Question 14

Describe fluid feeding and list some animals that use this method of ingestion.

Answer 14

Sucking nutrient rich fluid from living host.

Mosquitos, bees, aphids

Question 15

Describe bulk feeding and list some animals that use this method of ingestion.

Answer 15

Eating large chunks.

2 types:

Whole (swallow whole, modified jaws) - rock python

Pieces (tear food w claws, teeth, pincers, etc.) - humans

Question 16

What is mechanical digestion?

Answer 16

Breaking food into smaller pieces, increasing surface area, allowing for a higher rate of digestion.

Question 17

What is an adaptation in mammals allowing for more effective mechanical digestion?

Answer 17

Teeth.

Question 18

What are the 4 types of teeth and what are they used for?

Answer 18

Incisors (front) - thin and flat for biting and cutting
Canines (fangs) - sharp and pointy to kill
Premolars - sharp to shred
Molars - flat surface for grinding

Question 19

Describe the distribution of each tooth type in different diets.

Answer 19

Omnivore - equal distribution

Carnivore - large incisors and canines, many premolars, reduced molars

Herbivore - Reduced incisor and canines, premolars and molars used for grinding

Question 20

Define chemical digestion.

Answer 20

Enzymes splitting food into smaller molecules for absorption.

Question 21

What are the 2 types of chemical digestion? Define them.

Answer 21

Intracellular (atypical) - cells engulf food particles which are broken down by enzymes in vacuole

Extracellular (typical) - food broken down by enzymes inside of cells in chambers continuous with outside of body (alimentary canal)

Question 22

What is a digestive cavity and which animals have them?

Answer 22

A digestive tract with one opening, mouth and anus are the same hole, so food moves one way then back. Able to digest and distribute nutrients.

In simple body plans, platyhelminths, cnidarians

Question 23

What is a digestive canal and which animals have them?

Answer 23

Digestive tube with 2 openings (mouth AND anus).

Food moves in one direction with ordered, specialized regions for digestion and absorption.

Found in more complex body plans.

Question 24

What are the 2 main components of a mammalian digestive system?

Answer 24

An alimentary canal and accessory glands that secrete digestive juices through ducts.

Question 25

What are the mammalian digestive accessory glands?

Answer 25

Salivary gland, pancreas, liver, gall bladder.

Question 26

What enzyme breaks down carbohydrates and in what part of the digestive tract is it found?

Answer 26

Amylase - found in mouth, pancreas, small intestine

Question 27

What enzyme breaks down protein and in what part of the digestive tract is it found?

Answer 27

Proteases (mix of pepsin and acids) - found in stomach, pancreas and small intestine.

Question 28

What enzyme breaks down lipids and in what part of the digestive tract is it found?

Answer 28

Lipases (in bile) - found in pancreas, which release enzyme into small intestine

Question 29

How many bacterial species are there in the human digestive tract?

Answer 29

>400

Question 30

Describe an adaptation in the human digestive system which has increased surface area, allowing for higher absorption efficiency.

Answer 30

Small intestine! Small intestine is 6 feet long, projections of folds called villi on small intestine increase SA x 10. On the villi there are epithelial cells which have microvilli on them increasing SA x 50

Question 31

What is the approximate surface area of the human small intestine?

Answer 31

300m^2

Question 32

What is mutualistic symbiosis?

Answer 32

Mutually beneficial interaction between species

Question 33

What do animals have a hard time digesting (think plants)

Answer 33

Cellulose (plant tissue)

Question 34

How do animals digest cellulose?

Answer 34

Fermentation chambers which allow for food storage and digestion of cellulose by bacteria and protists.

Question 35

What is the fermentation chamber to break down cellulose in bids called and where is it located?

Answer 35

Crop - located right before stomach

Question 36

What is the fermentation chamber to break down cellulose in mammals called and where is it located?

Answer 36

Cecum - at the base of the ascending part of the colon (start of the colon, right beside appendix)

Question 37

Describe the correlation between digestive tract length and diet for herbivores.

Answer 37

Plant tissue is harder to digest, herbivores eat smaller amounts at a time, so stomach is smaller Large intestine is longer with higher SA and larger cecum.

Question 38

Describe the correlation between digestive tract length and diet for carnivores.

Answer 38

Animal tissue easier to digest, so carnivores eat larger meals, therefore stomach is larger and able to expand. Large intestine is shorter and smaller cecum.

Question 39

Explain how ruminants eat food.

Answer 39

1. Chew food which goes into stomach chambers 1 and 2 where cellulose is digested by microorganisms. 2. Cud regurgitated and chewed 3. Cud is swallowed going into chamber 3 where water is absorbed. 4. further digestion in chamber 4

Question 40

What morphological trait do all ruminants have in common.

Answer 40

4-chambered stomach

Question 41

What animals are ruminants.

Answer 41

Deer, cow, sheep

Question 42

What is coprophagy and name an animal that does it.

Answer 42

When animals eat feces to recover unabsorbed nutrients. Rabbits

Question 43

What harmful byproduct of digestion is specifically due to protein breakdown.

Answer 43

Ammonia

Question 44

What are the different forms of ammonia that an animal may excrete and which animals excrete it.

Answer 44

1. Ammonia - most toxic, high water loss, little energy required. Aquatic species. 2. Urea - medium toxicity, medium water loss, medium energy loss. Land species. 3. Uric acid - low toxicity and water loss, higher energy costs. Land reptiles, birds.

Question 45

Describe the first step in the process of excretion and where it occurs.

Answer 45

Filtration. Excretory tubule collects a filtrate (small molecules like water, NH3, salts) from blood. Passive

Question 46

Describe the second step in the process of excretion and where it occurs.

Answer 46

Reabsorption. Transport epithelium selectively reclaims valuable solutes (water, sugar, a^2) and returns to bodily fluids.

Question 47

Describe the third step in the process of excretion and where it occurs.

Answer 47

Secretion. Toxins and non-essential solutes are added to filtrate from blood.

Question 48

Describe the fourth step in the process of excretion and where it occurs.

Answer 48

Excretion. Filtrate (urine) leaves body.

Question 49

Describe a simple system network of tubules.

Answer 49

Network of dead-end tubules found in connected to external openings (ex. flatworms)

Question 50

Describe a complex system network of tubules.

Answer 50

Open ended tubules that collect fluid from coelom and produce urine. There is a pair/segment. Ex. annelids

Question 51

Describe the second most complex system network of tubules.

Answer 51

Malpighian tubules (tubules w dead end tips) that collect molecules from hemolymph which then go to digestive tract where solutes are reabsorbed. This produced a dry paste in the hindgut (uric acid) Ex. insects (grasshoppers)

Question 52

Describe the most complex system network of tubules.

Answer 52

Nephrons - long tubules that are very close in proximity to capillaries that span inner and outer kidney. Carry and process filtrate produced by blood entering kidney.