Diagram of Biology ccea as2 everything | Quizlet

What is biodiversity?

Variety of life

What is monoculture?

The growing of only one crop species in a particular area

What are the disadvantaged of monoculture?

- Reduced biodiversity

- Loss of certain minerals in the soil

- Pests/diseases specific to the crop can establish themselves in large numbers

What can increased dependence on artificial fertilisers lead to?

- Loss of soil crumb structure

- Increased risk of eutrophication

- Reduced biodiversity

Why does increased dependence on artificial fertilisers lead to loss of soil crumb structure?

Artificial fertilisers consist of soluble chemicals but no organic materials to improve soil crumb structure

Why does increased dependence on artificial fertilisers lead to increased risk of eutrophication?

The chemicals in the fertiliser are soluble so if it rains they will run-off or leach into waterways

Why does increased dependence on artificial fertilisers lead to reduced biodiversity?

The fertiliser encourages the fast growth of the target crop, allowing it to out compete and eliminate slower growing plant species

What are the benefits of hedgerows?

- Provide habitats for birds and insects

- Uncultivated margins provide habitats

- Act as wildlife corridors

How can loss of hedgerows occur?

- Hedgerows being cut too frequently or at the wrong time of year

- Overgrazing

- Failing to replant lost hedgerows

How can loss of hedgerows cause a reduction in biodiversity?

The natural habitats are destroyed and replaced by agricultural ecosystem, reducing the number of plant species present as well as the variety of niches and food types available for animals.

What is a pest?

A species that damages a valuable commercial crop

What is a pesticide?

A poisonous chemical used to kill pests

What is used to kill insect pests?

Insecticides

What is used to kill weeds competing with a crop?

Herbicides

How do pesticides decrease biodiversity?

Pesticide do not only kill their target species, they may also kill other species If natural predators are killed pest resurgence can happen.

What is polyculture?

Planting a variety of crops

What is intercropping?

Growing a range of crops at the same time

What is crop rotation?

Growing different crop species in a particular field over a number of years

Why is crop rotation beneficial to soil?

Each crop species will have different mineral requirements and therefore the soil is less likely to become depleted of one particular ion

How does crop rotation reduce problems with pests?

Changing the crop each year can help prevent the completion of the pest life cycle, making it harder for large pest populations to become established

Why does the use of organic fertiliser improve soil crumb structure?

The humus in the fertiliser holds the crumb structure together

Why does organic fertiliser have a reduced risk of eutrophication?

It releases minerals at a slower rate

How does biodiversity-friendly hedgerow trimming help increase biodiversity?

- Allowing hedgerow trees to reach maturity at intervals in the hedge, creating a variety of niches

- Only trimming on a 2 or 3 year rotation, allowing shrubs to flower and produce berries and maintaining nesting sites in at least part of the hedgerow each year

- Trimming during the winter to avoid destruction of birds nests and allowing berries to develop

- Maintaining a range of hedge heights and widths

- Protecting young hedgerow trees from grazing

How are biological control agents used to decrease pest populations?

Biological control means using specific predators/parasites of a pest in order to reduced its population. Natural predators can also be encouraged by the use of predator strips

How can the introduction of sterile males to a pest population help reduce the population size?

The males will see out and mate with the females of the species but no offspring will be produced

How does organic pollution of water occur?

When organic materials enter waterways the provide a rich supply of food for saprobiotic bacteria. This leads to a population explosion of bacteria who will use up much of the dissolved oxygen in the water. Other aquatic life cannot obtain enough oxygen and will therefore asphyxiate

What is eutrophication?

Mineral enrichment of waterways

How does eutrophication occur?

1. Nitrates and phosphates are added to the water by runoff or leaching

2. High mineral ion concentration leads to increased growth of algae etc.

3. The algae layer at the surface prevents light reaching other plants, causing them to die

4. The dead plants and algae are decomposed by saprobiotic bacteria, using up all the oxygen in the process

5. The shortage of oxygen results in the death of many species of fish and invertebrates - a loss of biodiversity

What are some of the risks associated with eutrophication?

- Loss of fisheries

- Health risks from drinking contaminated water

- High nitrate concentrations in drinking water can be harmful to young babies

How can organic pollution be decreased in waterways?

- Testing the ion concentration of the soil before applying organic fertilisers so the correct balance is added

- Only applying fertilisers during crop growth

- Not apply fertilisers when heavy rain is forecast

- Not apply fertilisers to land close to water ways

- Having adequate storage facilities to prevent spills

What are areas of special scientific interest?

Ecologically important areas with high conservation value

What are special areas of conservation?

Areas given special protected status under the EU habitats directive to conserve threatened habitats

What are the two main reasons for increased carbon dioxide in the atmosphere?

- Increased combustion of fossil fuels

- Deforestation

What is the greenhouse effect?

The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

When is methane produced?

When organic matter decomposes in an environment lacking oxygen

What are some of the predicted consequences of global warming?

- Melting of the polar ice caps leading to rising sea levels

- Climate changed

- Alteration of habitats

- Failure of crops

What factors does the Simpson's biodiversity index take into account?

The number of different species in the area and the number of individuals of each species present in the area

What is a habitat?

Place where an organism lives

What is an environment?

All the conditions that surround a living organism

What is an ecosystem?

The interaction of the community of organisms and the environment

What is a population?

A group of organisms of the same species living in a particular geographic area at a particular time

What is a community?

All the organisms of all species living in a particular area at a particular time

What is a niche?

How an organism fits into its environment

What is interspecific variation?

Variation between species

What is intraspecific variation?

Variation within a species

What is an allele?

A different form of a gene

What is genetic diversity?

The total number of different alleles in a species or population

Why does a greater genetic diversity mean a greater chance of long term survival?

The greater the range of alleles the greater the range of characteristics, meaning that there is a greater chance of individuals having characteristics that would suit them to changed environmental conditions

What factors may influence genetic variability?

- How long a species has existed

- What degree of directional selection has occurred

- If a species has become adapted to survive a wide range of environments

- The rate of mutation of DNA of a species

What is classification?

Organising living organisms into groups

What is a species?

A group of organisms which are so biologically similar that they can breed together and produce fertile offspring

What is taxonomy?

The scientific study of how living things are classified

What are the seven taxonomic ranks?

- Kingdom

- Phylum

- Class

- Order

- Family

- Genus

- Species

What is phylogenetic taxonomy?

The process of classifying organisms into groups according to the evolutionary relationship between organisms.

What is morphology?

The external features of an organism

What is anatomy?

The internal features of an organism

How can DNA base sequence help show how closely related species are?

The more similar the base sequences, the more closely related the species are and the more likely they had a common ancestor

What are the five kingdoms?

- Prokaryotae

- Protoctista

- Fungi

- Plantae

- Animalia

What is the kingdom Prokaryotae?

The kingdom containing bacteria and blue-green algae. They are all single cells with the cell structure prokaryotic

What is the kingdom Fungi?

The kingdom including moulds, yeast, mushrooms and toadstools. They can be unicellular or multicellular and have a eukaryotic cell structure. Their cell walls are made of chitin and they store glycogen as their storage carbohydrate. The have a lysotrophic mode of nutrition, meaning the feed on decomposing material in dead organisms

What is the kingdom Plantae?

The kingdom which includes mosses, ferns, conifers and flowering plants. They are multicellular and have a eukaryotic cell structure. The have autotrophic nutrition meaning the can make their own complex organic molecules from simple inorganic molecules by photosynthesis. Their cell walls are made of cellulose and some of their cells contain chlorophyll in chloroplasts. They store carbohydrates as starch and store lipids has oils

What is the kingdom Animalia?

The kingdom which includes flatworms, insects and chlorates. They are all multicellular and have a eukaryotic cell structure with no cell wall. The have heterophobic nutrition meaning they have to consume ready-made organic molecules, by eating a plant of another animal. They store carbohydrates as glycogen and story lipids as fats and are capable of locomotion.

What is the kingdom Protoctista?

The kingdom which includes algae and seaweeds. Sometimes referred to as a taxonomical dumping ground as the main characteristic of organisms in this kingdom is the inability to fit into any other kingdoms. They may be unicellular or multicellular but all have a eukaryotic cell structure. Some are autotrophic and able to photosynthesis and some are heterotrophic.

What are the three domains?

- Bacteria

- Archaea

- Eukarya

What types of factor may influence the distribution of organisms?

- Climatic factors

- Edaphic factors

- Biotic factors

What climatic factors can influence the distribution of organisms?

- Temperature range

- Water availability

- Light intensity

- Light quality

- Day length

How can temperature range affect the distribution of organisms?

Each species has an optimum temperature range in which it is best able to survive. For plants and ectothermic animals the further their environmental temperature is form their optimum temperature their less like they are to be able to survive in that habitat. Very low temperatures would decrease their chance of survival as their enzymes inside the organisms cells would have very little kinetic energy and would therefore work slowly. Very high temperatures could cause the enzymes to become denatured which would slow down the metabolic reactions. Endothermic animals can maintain a constant internal temperature despite changes in their environmental temperature, however environmental temperature can still affect their chance of survival as the further from their optimum temperature it gets the more energy they must expend on keeping their body temperature constant

How can water availability affect the distribution of organisms?

In habitats where water is scares communities consist of only a few species which are well adapted to living in dry conditions. Other plants are well adapted to living in or on water. Mammals have waterproof skin and internal gas exchange surfaces, allowing them to reduce water loss by evaporation.

How can light intensity affect the distribution of organisms?

Light is essential for photosynthesis so all plants, and ultimately all food chains, are dependant on it. As light intensity increases the rate of photosynthesis increases, leading to faster plant growth.

How can light quality affect the distribution of organisms?

Plants can only use certain wavelengths of lights for photosynthesis

How can day length affect the distribution of organisms?

A longer day length means more light will be available for photosynthesis and plants will tend to grow better. There may also be a correlation between day length and temperature.

What edaphic factors can influence the distribution of organisms?

- Soil pH

- Availability of mineral ions

- Water content of the soil

- Aeration of the soil

How can soil pH affect the distribution of organisms?

Changes in soil pH can affect the availability of certain mineral ions as well as leading to enzymes and other proteins becoming denatured

How can availability of mineral ions affect the distribution of organisms?

Plants need macronutrients in large amounts for healthy growth (e.g. - nitrates for proteins and calcium for cell walls). They require micronutrients in smaller amounts.

What factors may influence the availability of mineral ions in the soil?

- The type of rock the soil formed from

- Soil pH

- Addition of fertilisers

How can water content of the soil affect the distribution of organisms?

Most plant species grow well in moist but well-drained soil. Few species grow well in waterlogged soil as it will have low oxygen concentration and the root cells cannot get enough oxygen for aerobic respiration.

How can aeration of soil affect the distribution of organisms?

Most soil contains air spaces between the soil crumbs. The oxygen in the air spaces is used for respiration in root cells and by aerobic decay bacteria. Soil which is waterlogged or very compacted does not contain these spaces. Peat bogs are formed from the dead plant material which is only partially decomposed as the decay bacteria cannot get enough oxygen in waterlogged soil.

What biotic factors can influence the distribution of organisms?

- Competition

- Predation

- Accumulation of waste

What is intraspecific competition?

Competition between members of the same species

What is interspecific competition?

Competition between members of different species

What is an ecological niche?

An organisms role in its ecosystem

How can competition affect the distribution of organisms?

When populations of two different species occupy the same ecological niche one will generally have a competitive advantage over the other and will out-compete it, causing the dominant species population to increase in size while the other species population decreases in size

What is the competitive exclusion principle?

No two species can occupy the same niche if resources are limiting

What is predator?

an organism that feeds on another organisms

How can predation affect the distribution of organisms?

A predator will hunt prey, decreasing it's population size

How can accumulation of waste affect the distribution of organisms?

This is commonly seen in the growth of microorganisms. As a population of bacteria increases the bacteria will produce increasing amounts of waste products. The accumulation of waste chemicals may restrict growth of further microorganisms.

What are the two types of sampling?

Systematic and random

How is a line transect used?

A tape measure is laid down as a transect line and, either continuously or at intervals, every individual that is touching the line is recorded

How is a belt transect used?

Quadrats are placed continuously alongside a transect line so that a whole belt of land is samples

How is an interrupted belt transect used?

Sampling is carried out at intervals along the transect line, usually due to the distance being sampled

When is percentage cover recorded?

When the species is particularly abundant or hard to count

When is number of organisms recorded?

When the species is not particularly mobile

What is plasma?

The fluid matrix of blood

What does plasma transport?

Blood cells, glucose, amino acids, mineral ions, carbon dioxide, urea, plasma proteins (e.g. prothrombin, fibrinogen, clotting factors), heat etc

What are platelets?

Cell fragments

How are platelets formed?

Cell fragmentation of large cells in in bone marrow, called megakaryocytes

Why is blood clotting important?

It reduces blood loss at a wound and prevents the entry of pathogens through a wound

What is the process of blood clotting?

1. Damage to tissue/blood vessel

2. Platelets activate and released clotting factors such as thromboplastin

3. Prothrombin catalyses to thrombin in the presence of Calcium ions, vitamin K and clotting factor VIIII

4. Fibrinogen catalyses to fibrin which then forms a mesh that traps blood cells and forms a clot

Where are red blood cells made?

Bone marrow

Why does a small size make red blood cells efficient for absorbing and transporting oxygen?

There is a decreased distance for diffusion of oxygen and it allows them to fit through capillaries