Investigating populations and succesion

Question 1

Biodiversity

5

Answer 1

The number of species and the number of individuals of each of the different species within one community

Question 2

Species Richness

Answer 2

The number of different species within a community

Question 3

Community

Answer 3

All the individuals of all the species living together in the same area at the same time

Question 4

Species

Answer 4

Group of similar organism with the same genes that reproduce to produce fertile offspring

Question 5

Genetic Diversity

Answer 5

Difference in DNA

Question 6

Niche

Answer 6

Describes where an organism lives and what it does, including what it feeds on and how it interacts with other organisms and the environment.

Question 7

Habitat

Answer 7

Place where organisms live in an ecosystem

Question 8

What information is required to calculate an index of diversity for a particular community

Answer 8

Number of species, number of individuals in each species

Question 9

the number of species present is one way to measure biodiversity. Explain why an index of diversity may be a more useful way to measure

Answer 9

also measures number of individuals of each species. some species may be present in low and high numbers.

Question 10

2 advantages of using an index of biodiversity rather than an indicator species

Answer 10

you don’t need to identify each species, index considers the number of organisms of each species.

Question 11

economic argument for maintaining biodiversity

Answer 11

medical/pharmaceutical use, commercial products, tourism, agriculture, saving local forest communities.

Question 12

farming

Answer 12

Decrease in the variety of plants- fewer plant species. Fewer habitats, decrease in variety of food sources, clearing forest through machinery or pesticides.

Question 13

Clearing a tropic forest for crops- why does this cause diversity of insects to decrease

Answer 13

lower diversity of plants, few food sources, few habitatas, fewer species of herbivore so few species of carnivores, kills insects

Question 14

Taxonomy

Answer 14

Theory and practice of classification
Binomial naming system- first word= genus. second word= species name.
classification system:Domain, kingdom, phylum, class, order, family, genus, species
Phylogenetics- all share a common ancestor

Question 15

courtship

Answer 15

display this behaviour to attract a mate of the same species of opposite sex. Important to ensure reproductive success.
1. Attracts same species of the opposite sex, indication of sexual maturity, stimulates release of gametes. form bond pair

Question 16

modern classification methods

Answer 16

frequency of measurable or observable characteristics, the base sequence of DNA, base sequence of mRNA, amino acid sequence of proteins encoded by DNA and mRNA

Question 17

Genetic comparisons and DNA

Answer 17

genetic- made by examination of their DNA, mRNA or of the proteins coded for by this DNA, classified within their genome.
DNA- the more closely related the species the more similar their DNA base sequence.

Question 18

Comparing the base sequence of a gene provides more information than comparing the amino acid sequence for which the gene codes. Explain why

Answer 18

Longer base sequence than amino acid sequence. Introns, same amino acid may be coded for and a DNA code may be degenerate

Question 19

Comparing base sequence provides more evolutionary information. Explain why

Answer 19

More bases than amino acids, introns, degenerate code

Question 20

Population

Answer 20

All the individuals of a given species living together in the same area at the same time

Question 21

carrying capacity

Answer 21

carrying capacity is the maximum, equilibrium number of organisms of a particular species that can be supported in a stable environment. birth rates and death rates are in equilibrium.

Question 22

ecosystem

Answer 22

a community made up of living organisms and their interactions with non-living components such as water and mineral soil

Question 23

why do two species not have exactly the same niche?

Answer 23

different roles within the ecosystem . they would outcompete and one would be more successful.

Question 24

what happens when niches overlap

Answer 24

species have adaptations that outcompete

Question 25

method of quadrating

Answer 25

map the area using two tape measures. use a random number generator, place a quadrat at each intersection. can only measure stationary and slow moving populations

Question 26

why is it incorrect to say that organisms live in the same niche

Answer 26

different organisms may operate the same ecological niche whilst competing until one is eliminated.

Question 27

how to know when to stop quadrating

Answer 27

calculate running mean, stop sampling when there is little change, enough to carry out a statistical test, a large number to make sure it is reliable, need to make sure it can be completed in the time available.

Question 28

what rules are there for calculating an estimated population

not biased and random
all data is reliable and representable

Answer 28

not biased and random
all data is reliable and representable

Question 29

quadrating

Answer 29

density- actual account of all individuals present- limitations- often time consuming, difficult to count
most accurate
percentage cover- the area of the quadrat covered by one species is recorded as a percentage of the total area. used when there are too many individuals to count. overlaying species may occur, total percentage may be over 100%
frequency- proportion of quadrat that contains a particular species. least accurate

Question 30

factors affecting distribution

Answer 30

Biotic- competition, invasive species, human impact, algae
abiotic- climatic factors, physical factors such as soil and ater PH, aspect (NESW), turbidity and salinity of water.

Question 31

systemic sampling

Answer 31

transect- recording what species are touching the line at each sampling point
belt transect- placing two parallel lines across, a meter apart and recording what species are found between the two lines
interrupted belt transects- using one line and placing a quadrat down at equally spaced sampling points and recording abundance in each quadrat.

Question 32

sere

Answer 32

complete succession from pioneer community to climax community- has its own distinctive community of organisms.

Question 33

mark release recapture

Answer 33

animals are ethically collected, animals are then marked, animals are released and left to redistribute into their population, recapture.
calculation: Number caught the first time x caught the second time/ number caught the second time that were previously marked.

Question 34

pioneer species

Answer 34

the organisms that first colonise an area

Question 35

climax community

Answer 35

final stage in an ecological succession- most stable, formed depending on abiotic factors

Question 36

diversity

Answer 36

the relationship between the number of individual organisms and the number of species within a community.

Question 37

stages of succession

Answer 37

colonization by named pioneer species, change in environment, enables other named species to colonise, change in diversity, stability increases, climac community represented by named species.
secondary succession occurs after forest fire or clearance of agricultural land.
deflected succession- when climax community is prevented from being established. community maintained under such conditions is known as a plagioclimax.