11 Ag Science

Question 1

True or False? .001, H+, pH 3

Answer 1

True - .001 ___1___
10x10x10
10 to the power of -3 = pH3 H+ ions

Question 2

Ethylene

Answer 2

Ripening of fruit, release of dormancy, stimulate shoot root growth, stimulate leaf abscission

Question 3

Cytokinin’s

Answer 3

controls major growth periods of the plant, linked to ethylene to control abscission of flowers, leaves and fruits

Question 4

Stigma

Answer 4

Female part of flower, top of pollen receptacle, becomes style, leads to ovary

Question 5

Pistil

Answer 5

Female collective parts of flower

Question 6

Anther/Filament

Answer 6

Pollen producers stamen

Question 7

Photosynthesis

Answer 7

6 CO2 + 6H2O –> C6H12O6 + 6O2

Question 8

Structure Soil

Answer 8

Percentage of Sand, Silt, Clay

Question 9

Nitrogen

Answer 9

Macro - involved in cell function division, protein synthesis, photosynthesis transfer of energy

Question 10

Epigeal Germination

Answer 10

cotyledons pushed above soil line until provide energy until photosynthesis takes over

Question 11

Heritability

Answer 11

P = G + E
30% Genetics
70% Environment

Question 12

Sperm morphology

Answer 12

Motility
LDR
Misshapen
Numbers

Question 13

Environment/Management

Answer 13

Can influence phenotype e.g. supplementary feeding, shade, temperature control, vaccination, irrigation, windbreak

Question 14

Protein

Answer 14

Crude Protein
NPN (non protein nitrogen)

Question 15

‘Trumpeter’

Answer 15

Gonadotrophin release, controlled by Hypothalamus

Question 16

Name the key player in ruminant protein digestion

Answer 16

Rumen microbes are the key player in protein digestion as they serve a key role in breaking down proteins and other nutrients in the rumen.

Question 17

Explain the differences in the anatomy of a monogastric animal compared to a ruminant

Answer 17

Monogastric - one stomach
Ruminant - four compartments and one true stomach - ABOMASUM

Question 18

The rumen is a fermentation tank. Explain the design/operation of this tank

Answer 18

The rumen is the main fermentation chamber in ruminant animals, where microbes break down fibrous plant material into VFA’s. It operates under anaerobic conditions, aided by saliva’s buffering capacity to maintain pH balance. VFAs are absorbed through the rumen wall and serve as a major energy source. Rumen contractions mix contents for efficient fermentation. This process not only provides energy but also synthesizes microbial protein and essential nutrients, crucial for the animal’s nutrition and health.

Question 19

NaHCO3

Answer 19

Sodium Bicarbonate
- Buffering: It can serve as a buffering agent in irrigation water to prevent large fluctuations in pH that could harm crops.
- Livestock Feed: It is sometimes used as a feed additive for livestock to help maintain proper pH balance in the digestive system.

Question 20

The ‘Bomb Calorimeter’ what does this measure

Answer 20

Measures the calorific value or heat of combustion of a substance. Specifically, it determines the amount of heat released when a substance is completely burned in an oxygen-rich environment.

Question 21

Calories/Kilojoules

Answer 21

Calories (kcal) measure energy in nutrition, while kilojoules (kJ) are the SI unit of energy used in scientific contexts. One kilocalorie (kcal) equals approximately 4.184 kilojoules (kJ). Both units are crucial for understanding food energy and are commonly used in food labelling and dietary recommendations.

Question 22

Protein Digestion

Answer 22

When protein is digested it is broken down into peptides (short chains amino acids) which then becomes NH4+ and NH3-

Question 23

Two types of protein

Answer 23

Non protein nitrogen
Crude protein

Question 24

Crude protein

Answer 24

Protein that needs to be broken down to a usable form

Question 25

NPN

Answer 25

Non Protein nitrogen

Question 26

Rumen Microbes

Answer 26

Major source of protein in a bovines diet. Breaks down CP and NPN to NH4+ and NH3-

Question 27

Microbes role

Answer 27

Break down protein
Continually flushes from the rumen to OMASUM to ABOMASUM
Are then absorbed

Question 28

If energy is limited?
poor quality feed
low microbe numbers

Answer 28

Microbes become less efficient at using NH3- instead of being converted to microbial protein they are absorbed across rumen wall into bloodstream (liver) converted to urea and excreted as urine