General ecology/ecosystems and classification stuff

Question 1

Habitat biodiversity -

Answer 1

The number of different habitats found within an area.

Question 2

Species biodiversity is defined by the use species richness and evenness -

Answer 2

Richness - the number of different species living in a particular area
Evenness - a comparison of the number of individuals of species living in a community.

Question 3

Genetic biodiversity -

Answer 3

Refers to the variety of genes that make up a species

Question 4

Calculating Simpsons index of diversity

Answer 4

D = 1- sum off (n divided by N) squared
N = total number of organisms of all species
n = the total number of organisms of a particular species

Question 5

Factors affecting biodiversity -

Answer 5

Genetic bottleneck, natural selection, the founder effect, genetic drift - due to the random nature of alleles being passed on from parents to their offspring, the frequency of that allele will vary. Genetic drift described populations with a low genetic diversity.

Question 6

Methods of maintaining biodiversity

Answer 6

Conservation is the name given to preservation and careful management and resource, conserving the natural habitat gives a greater survival chance of organisms and allow them to reproduce.

Question 7

In situ conservation -

Answer 7

Within the natural habitat, wildlife reserves allow the maintenance and genetic diversity. Evolutionary adaptations too.

Question 8

Ex situ conservation -

Answer 8

Out of the natural habitat. Seed banks or captive breeding programmes, where they produce offspring in a human controlled environment.

Question 9

Classification and why do they do this? -

Answer 9

Name given to the process by which living organisms are sorted into groups.
To identify species , predict characteristics and to find evolutionary links

Question 10

How are organisms classified -

Answer 10

Into 3 domains - Archaea, Bacteria and Eukarya

Question 11

5 kingdoms -

Answer 11

Prokaryotae, protoctista, fungi, plantae and animalia

Question 12

Phylogeny -

Answer 12

Name given to the evolutionary relationship between organisms, revealing which group of organism you are related to and how closely related they are.

Question 13

Phylogenetic tree -

Answer 13

Used to represent the evolutionary relationships between organisms, branched diagrams and show how such species have evolved from a common ancestor.

Question 14

Evidence for evolution -

Answer 14

Palaeontology - study of fossils
Comparative anatomy - study of comparisons of organisms anatomy
Comparative biochemistry - Comparison of the chemical makeup of organisms.

Question 15

Causes of variation -

Answer 15

An organisms genetic material so genetic variation. The environment.

Question 16

Genetic causes of variation -

Answer 16

Alleles, mutations and meiosis (independent assortment and crossing over)

Question 17

Adaptations -

Answer 17

Certain characteristics that increase an organisms chance of survival and reproduction in its environment.

Question 18

Types of adaptations -

Answer 18

Anatomical - physical features (internal and external)
Behavioural - the way the organism acts, can be inherited
Physiological - Processes that take place inside an organism.

Question 19

Anatomical adaptations (physical) -

Answer 19

Body covering - may help organisms fly or stay warm
Camouflage - Help blend in to the environment, making it harder for predators to spot them.

Question 20

Behavioural adaptations -

Answer 20

Survival behaviours - Opossum plays dead and rabits freeze
Courtship - many animals exhibit courtship to attract a mate.

Can even be seasonal behaviours through migration

Question 21

Physiological adaptations -

Answer 21

Poison production - many reptiles produce venom to kill
Antibiotic production - some bacteria produce antibiotics to kill other species of bacteria in the surrounding area.

Question 22

Selection pressures -

Answer 22

Factors which affect the chances of survival where organisms best adapted to their environment are more likely to thrive.

Question 23

Modern examples of evolution =

Answer 23

Peppered moths - where black moths became more suitable to survive as during the industrial revolution trees became darker allowing these moths to blend in whereas, white moths had now become more vulnerable.
Antibiotic resistant bacteria - MRSA has developed resistance to many antibiotics. Bacteria reproduce rapidly. When they replicate their DNA can be altered however a mutation arose and provided them with resistance.

Question 24

Ecosystem -

Answer 24

An ecosystem is made up of all living organisms that interact with one another in a defined area

Question 25

Trophic levels -

Answer 25

First trophic levels are always producers, where they convert light energy into chemical energy by photosynthesis. Subsequent trophic level are always consumers organisms that obtain their energy by feeding on other organisms.

Question 26

Measuring biomass -

Answer 26

Biomass is the living material present in a particular place or in organisms. Important in understanding tropic levels, however water content must be discounted. To calculate biomass at each trophic level you multiply the biomass in each organism by the total number of organisms in that trophic level.

Question 27

Efficiency of biomass between trophic levels -

Answer 27

The biomass in each trophic level is always less than half than the trophic level below.

Question 28

Decomposition -

Answer 28

Chemical process in which compounds are broken down into smaller molecules or its constituent elements. A decomposer is an organism that feeds on and breaks down dead plant or animal matter and absorb these inorganic compounds.

Question 29

Detritivores -

Answer 29

They help speed up the decay process by feeding on a dead and decaying material.

Question 30

Nitrogen fixation -

Answer 30

Enzyme nitrogenase in some bacteria causes nitrogen fixation of atmospheric nitrogen and hydrogen to produce ammonia which is absorbed by plants.

Question 31

Nitrification is an oxidation reaction and so only occurs in well aerated soil due to nitrate soils -

Answer 31

Nitrate ions are highly soluble and therefore the form in which most nitrogen

Question 32

Denitrification -

Answer 32

In the absence of oxygen, denitrifying bacteria convert nitrates in the soil back into nitrogen gas happens under anaerobic conditions.

Question 33

Ammonification -

Answer 33

Name given to which decomposers convert nitrogen-containing molecules in dead organisms into ammonium compounds.

Question 34

Succession -

Answer 34

Ecosystems changing over time two types, primary and secondary succession.

Question 35

Primary succession -

Answer 35

Occurs on an area of land that has been newly formed or exposed as bare rock, there is no or organic material.

Question 36

Secondary succession -

Answer 36

On areas of land where there is soil present, but no plants or animal species

Question 37

Stages of succession -

Answer 37

Each step is knows as a seral stage, at each stage key species can be identified that change the abiotic factors, especially the soil, to make it more suitable.

Question 38

Pioneer community -

Answer 38

Primary succession begins by the inhospitable environment, by organisms known as pioneer species. These species arrive by spores or seeds carried by wind from nearby landmasses, these may have some useful adaptations of high germination and the ability to produce large quantities of seeds or spores.

Question 39

Intermediate community -

Answer 39

When some of the pioneer species die and decompose small organic products are released into the soil the soil become able to support the growth of new species, known as secondary colonisers, as the conditions continue to improve, new species of plant arrive.

Question 40

The final seral stage is climax community -

Answer 40

Defined to be in a stable state, will very little future change, elimination may occur of some species due to more dominant ones. Human activities can result in deflected succession of an ecosystem and stop it from reaching a climax community, this is known as plagioclimax.

Question 41

Plagioclimax -

Answer 41

Where human activities result the halt of naturally flowing mechanisms in succession. v