Nutrients

Question 1

Food chain and levels

Answer 1

food chain is the circular system of nutrients acquisition of organisms

primary, secondary, tertiary and quaternary trophic levels

each organisms occupies a specific level based on their place in the food chain

Question 2

autotrophs

Answer 2

those who make their own food/photosynthesis

chemoautotrophs- transform energy from chemicals. Occurs in places with high conc. of specific inorganic compounds (H, S)

photoautotrophs- transform light energy

plants and some bacteria

Question 3

heterotrophs

Answer 3

those who cannot produce their own food

therefore they must get energy from autotrophs

herbivores but also carnivores and omnivores

Question 4

detritivores

Answer 4

also known as decomposers. They consume already dead organisms, and can exist on any trophic level and play a critical role in recycling in the ecosystem

Question 5

chemosynthesis in depth

Answer 5

occurs in ecosystems that lack sunlight and have high conc. of inorganic compounds such as H or S

can be symbionts with heterotrophs

There are many different pathways
Below is a pathway that bacteria and archaea use in hydrothermal vents

H2S and CO2 and O2 –> glucose, water and S

major pathways include: Calvin benson cycle, and reductive carboxylic acid cycle

Question 6

What are the nutrients that plants need

Answer 6

17 overall

C, H, O, P, N, K, Ca, Mg, S, Cl, Fe, Mn, Bo, Cu, Mo, Zn, Ni

some are required in large quantities, and others in smaller amounts

Question 7

How to plants get nutrients, what are their issues?

Answer 7

• Some nutrients must be taken up through the soil
• Plants often require the assistance of other organisms to take up these soil-bound nutrients
• Plants can generally reuse waste compounds or metabolic by-products, however, imbalances do occur, especially with regard to excess water
• Plants have developed a number of ways to ensure they do not retain excess water in their tissues

Question 8

Nitrogen fixation

Answer 8

○ Soil-dwelling bacteria convert atmospheric nitrogen (triple bonded and hard for plants to break up), into ammonia (NH3), which is then converted into ammonium (NH4) or nitrate (NO3), which can be taken up by the plant
○ Requires large amounts of ATP which bacteria get from plant-derived carbs
○ Nitrification (2 step process that converts N2 into ammonia)
○ Provides plants with a form of nitrogen that they can use to synthesis proteins and nucleic acids

Question 9

N fixation in Legumes

Answer 9

○ In legumes, nitrogen fixation occurs at nodules
○ This includes rhizobacteria
§ They do nitrogen fixation
§ Also protect by producing antibacterial agents
§ And through other ways

Question 10

Fungal Mycorrhizae and other fungi

Answer 10

○ Important to plant nutrition, function in water acquisition, growth factor signalling and plant protection
○ Can help collect phosphate, copper and zinc
○ Produce antibiotics and protect against other pathogens

- Ectomycorrhizae 
	○ Covers roots and helps absorb water and minerals
- Arbuscular mycorrhizae 
	○ Embedded within root tissue, increasing contact between the plant cells and the branching filaments of fungus, called hyphae

Question 11

How do plants mainly excrete (2 main categories)

Answer 11

• These metabolic processes often produce by-products that are toxic to the organism and therefore need to be removed
  
  • Control of excess water and gasses occurs primarily in the leaves and roots

Question 12

Transpiration

Answer 12

• Transpiration controls water homeostasis, and facilitates the diffusion of excess oxygen out of the plants via the stomata
  
  • Evaporation of water vapour from open stomata generates pressure in the leaves which draws water up the plant’s stem via the xylem and facilitates the absorption of water via the roots
  • This is dynamic and reversible and responsive to a number of environmental and intrinsic signals
  • Some plants permanently open pores on the stem
  • Lenticels provide another avenue for unwanted water and gasses to exit

Question 13

Urea

Answer 13

• Plants therefore generate urea (nitrogenous waste product) that needs to be removed
  
  • Often converted and reused for protein synthesis
  • Plants can store unwanted metabolic by products in vacuoles
  • The waste then builds up in time in the tissues, which are then discarded as the tissue ages (e.g. fruit, leaves and bark)

Question 14

Guttation

Answer 14

• During the day, stomata can open and close, however, in the night excess water accumulates as the stomata’s are closed and the roots still absorb water due to root pressure
  
  • Therefore some plants undergo guttation in order to excrete this excess water
  • Water can also be eliminated through guttation
    ○ Exudation of xylem sap in the form of water droplets through structures called hydathodes
  • It occurs when root pressure exceeds transpiration and forces the xylem sap through the secretory cells in the leaf epidermic called hydathodes

Question 15

How do fungi feed?

Answer 15

• Fungi feed by growing into their food source.
• Fungal cells exude digestive enzymes into the surrounding substrate or tissue which breakdown large macromolecules that are then absorbed across the cell wall.

Question 16

How does digestion and nutrient transport in animals work?

Answer 16

• Digestion & nutrient transport in animals occurs via two main systems- the digestive system and the circulatory system.

Question 17

what is the purpose of heterotropic fungi

Answer 17

unlock essential nutrients, returning them to the soil or directly into plants

therefore, facilitating plant growth and nutrient cycling

Question 18

what is the purpose of nutrient transport?

Answer 18

After the digestive system breaks down a molecules, essential nutrients are transported across the body of an organism via the circulatory system through nutrient transport

Question 19

How does simply digestion work?

Answer 19

simplest digestive systems are found in the simplest animals (like sponges) and consist of water flowign in and ou tof the body in water channels, where individual cells capture food particles

Simple cuts are found in other organisms, where there is a single opening to the gut/gastrovascular cavity. The cavity is lined with many different cell types which produce digestive enzymes and absorb nutrients

Question 20

what are the 3 main sections of the digestive tract?

Answer 20

foregut
midgut
hindgut

Question 21

foregut purpose

Answer 21

intake and storage of food
initial stages of chemical and mechanical digestion

Question 22

midgut and hindgut

Answer 22

primarily important for chemical digestion and absorption of nutrients prior to defecation
the length and structure differ based on the food consumed by each animal

Question 23

herbivores digestive system

Answer 23

eat plant matter which is hard and slow to break down into a food source
uses grinding, rasping, cutting and shredding of their food, therefore a different mouthpart evolved (lots of molars, no canines, strong jaw (therefore wide cheek bone to attach to))
convergent evolution in many herbivores
very muscular stomach
foregut contains acids and digestive enzymes

Question 24

Ruminants what are they and their digestive system parts

Answer 24

herbivores that have specialised extensions in their stomach to prologn the digestive process (mixing enzymes and acids in the food in teh stomach due to muscle contractions), in order to properly break down food

4 compartments in their stomach
1. rumen
2. reticulum
3. omasum
4. abomasum

Question 25

What is rumination?

Answer 25

food is consumed and fermented in either the foregut or hindgut then the food is regurgitated from the rumen into their mouth for mechanical digestion (rumination)

Question 26

what are foregut fermenters?

Answer 26

food is passed throgh the different stomach region, where plant matter is fermented by the assistance of an array of microbes also known as foregut fermenters the food can then undergo rumination

Question 27

What are hindgut fermenters

Answer 27

fairly simple stomach. Rely on strong hindguts where the caecum is the specialised region that possesses an array of microbes for fermentation of plant food the food can then undergo rumination

Question 28

carnivores digestive system

Answer 28

flesh can be easily chemically broken down, therefore teeth are mainly there to capture prey and shearing through their flesh rely more on chemical digestion, with salivary enzymes and the stomach and foregut are highly acidic proteins=stomach/foregut digestion lipids=midgut digestion the digestive system is shorter and less complex because it is easier to digest, and large SA:V due to folding of vili and microvili

Question 29

Nitrogenous wastes, what are they?

Answer 29

nitrogen is released when proteins and nucleic acids are broken down for energy or conversion into carbs or fats proteins --> amino acids nucleic acids --> nitrogenous bases both are converted into nitrogenous wastes, of which there are 3 types 1. ammonia 2. urea 3. uric acid