Density dependent
Factors that affect a population's growth rate based on size and density, such as competition for resources, predation, and disease.
Density independent
Environmental factors that affect the population size of a species regardless of the population density, such as natural disasters, climate change, and habitat destruction.
Transducer
Converts one form of energy into another eg. a chloroplast in photosynthesis.
Cyclic Phosphorylation
Returns to photosystem two again
Molecules in the calvin cycle
RuBP, GP and TP
Role of nitrogen in plant metabolism
The production of chlorophyll, Without sufficient nitrogen, plants may exhibit stunted growth, yellowing of leaves, and reduced yield.
Role of magnesium in plant metabolism
It is also involved in the synthesis of chlorophyll, the green pigment that gives plants their colour and helps them absorb light. It is required for the activation of many enzymes. Plants will appear wilted with brown or black spots.
Role of phosphorous in plant metabolism
It helps in the formation of DNA and RNA, and the activation of enzymes. A deficiency of phosphorous can lead to stunted growth and brown edges on the leaves.
Role of calcium in plant metabolism
It helps in the formation of cell walls and the transport of other nutrients within the plant. Calcium deficiency can lead to stunted growth, poor fruit quality, and increased susceptibility to diseases. The leaves will be very small and even dark green in colour.
What is the energy budget of glucose?
This refers to the amount of energy produced when glucose is broken down into pyruvate.
How are lipids used in respiration?
Lipids are broken down into fatty acids and glycerol, which are then converted into acetyl-CoA. Acetyl-CoA enters the Krebs cycle, producing ATP through oxidative phosphorylation. Lipids are a major source of energy during prolonged exercise or fasting. However glucose is a quicker substrate.
How are amino acids used in respiration?
Amino acids can be converted into pyruvate, acetyl-CoA, or other intermediates of the citric acid cycle to be used as a source of energy in respiration.
What is viable cell count?
Viable cell count is a method used to determine the number of live cells in a given sample.
What is simple quantative treatment in populations?
Simple quantitative treatment in populations refers to the use of basic statistical methods to analyze and interpret data related to a population, such as calculating measures of central tendency and variability, conducting hypothesis tests, and estimating confidence intervals.
What is a trophic level of a population?
A trophic level is a position in the food chain of an ecosystem, occupied by a group of organisms that have a similar feeding mode.
What is net production in a food chain?
Net production in a food chain is the amount of energy that is available to the next trophic level after the energy lost due to respiration and other metabolic processes.
What is a pyramid of biomass?
A pyramid of biomass is a graphical representation of the total amount of living matter at each trophic level in an ecosystem.
What is sere in succession?
Sere is the stage of ecological succession where the community of plants and animals has reached a stable state and is no longer changing significantly over time.
What is carrying capacity of a population?
Carrying capacity is the maximum number of individuals that a particular environment can sustainably support over a long period of time.
What is a climax community in a population?
A climax community is a stable and self-sustaining community of plants and animals that has reached a state of equilibrium with its environment. It is the final stage of ecological succession and is characterized by a diverse range of species that are well adapted to the prevailing environmental conditions.
What are the different stages of the carbon cycle?
The different stages of the carbon cycle are photosynthesis, respiration, decomposition, combustion, and sedimentation.
Where is the dorsal root found?
The sensory neurone.
Where is the ventral root found?
The motor neurone.
What type of nervous system does a cnidaria have?
A nerve net.
Adaptations of the PCT in the kidney for absorption.
Cuboidal epithelial cells with a brush border (microvilli) to increase surface area. (brush border). Tight junctions allow high capacity fluid reabsorption. Basal channels increase surface area. Many mitochondria for ATP production for active transport. Capillaries in close contact. Large amount of RER and golgi bodies for protein production.
Steps involved in the crystal violet staining method.
Heat fix a smear of bacteria
Stain using crystal violet stain
Fix the stain with iodine
Decolourise with alcohol
Counterstain with safranin.
Describe cotransport
In the gut, glucose and sodium are transported together. Glucose is diffused and sodium is actively transported however they arrive at the cotransport protein embedded in the membrane together.
Seral stage
Describes an individual stage in succession.
Which limb of loop of henle is thicker and why?
Ascending due to the increased pressure required to push upwards. It is also impermeable to water.
What factors affect the speed of an impulse? (3)
Temperature, if it is myelinated or not and the diameter of the axon.
Where do lipids enter respiration?
Fatty acids into the Krebs cycle as they are converted into acetyl-coenzyme A. Glycerol into glycolysis as one of the intermediates.
Where do amino acids enter respiration?
Amino acids can enter in glycolysis. they can be deaminated and be converted to pyruvate or they can be converted into one of the intermediates in the Krebs cycle.
Locations of ATP synthesis
Mitochondria= Inner membrane and matrix.
Chloroplasts= Thylakoid membrane and stroma.
What are planetary boundaries?
A framework to describe limits to the impacts of human activities on Earth. Beyond these the earth may not be able to self regulate anymore. The earth would leave holocene.
The planetary boundaries (9)
Climate Change 2) Ocean acidification 3) Ozone depletion 4) C02 emissions 5) Global freshwater use 6) Land system change eg. ice-caps melting 7) Erosion of biosphere integrity eg. species extinction 8) chemical pollution 9) atmospheric aerosol loading
Nitrogen fixing bacterium
Rhizobium + Azotobacter
Nitrifying bacterium
Nitrosomonas + Nitrobacter
Denitrifying bacteria
Pseudomonas + Thiobacillus
Abiotic Factor
Non-living part of an ecosystem eg. light, water, temperature and ocean currents.
Biotic factor
A living thing that shapes its environment or other living things eg. predation, competition, pollination.
Adaptations of the glomerulus for its function.
Afferent arteriole is wider than the efferent creating pressure. Podocytes form a filtration barrier and support the structure of the glomerulus. They have projections which form the barrier. Filtration slits in the capillaries. A basement membrane doesn’t allow proteins in.
1 reduced NAD makes…
3 ATP
1 reduced FAD makes…
2 ATP
1 glucose in respiration produces…
38 ATP
What makes ions considered organic?
If the contain carbon
Benefits of ATP
Releases energy in small amounts so none is wasted.
Small, soluble and easily transported.
Only 1 bond broken to release energy so this is immediate.
Can transfer energy to other molecules through phosphate groups.
Cannot pass out of cell, so supply of energy is always there.
the Bohr effect
To do with the affinity for oxygen and which species have their haemoglobin adapted to have a higher affinity based on environment. Higher affinity is on the LEFT of the graph.
What does PCB stand for (human impact topic)
PolyChloriated Biphenyls
Reasons a species can become extinct to do with human activity.
Deforestation, removing hedges, chemical pollution, Alien species (outcompete, disease), monoculture, building houses/factories and unsustainable farming eg. overfishing/farming
Ways to achieve conservation
SSSI’s, CITES (restriction of ivory trade by the government), banning whaling and poaching, legislation to prevent overfishing, breeding programmes in zoos, sperm banks and seed stores, pollution control and species reintroduction programmes.
Why is genetic diversity essential?
To ensure a species can survive any changes to its environment by adapting. Some alleles may be useful to humans eg. plants having medicinal uses and captive breeding programmes have a responsibility to maintain genetic diversity.
Eutrophication
Caused by fertilisers running into waterways.
Define desertification
A process where soil becomes infertile and unable to support any life, generally accompanied by soil impaction and drying.
What is environmental monitoring?
It describes physical and biological measurements that are made over a period of time
What are physical measures?
Physical measurements might include pH, drainage or water flow.
GPP
General primary productivity. The amount of energy that is in one trophic level
NPP
Net primary productivity. The GPP-R to find out how much energy is transferred to the next trophic level.
Where does glycolysis occur?
Cytoplasm (cytosol)
Where does the link reaction occur?
mitochondrial matrix
Where does the krebs cycle occur?
Mitochondrial matrix
Where does oxidative phosphorylation (ECT) occur?
Mitochondrial inner membrane (cristae)
Is oxygen required for glycolysis?
No. It can happen aerobically and anaerobically
What is sedimentation (carbon cycle)?
The same thing as fossilisation. Forming rocks from small pieces of sand or stone which have been left behind by water, wind or ice. This is how fossil fuels are created.