CAP 1 revision

Question 1

Biodiversity

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

ATP

Answer 20

Adenosine Triphosphate- useful because it releases energy in small, manageable amounts, it’s broken down in one-step, immediate energy compound, phosphorylase’s, released instantaneously, rapidly re-synthesised.

Question 21

Chloroplast

Answer 21

key structures of a chloroplast- lamellae joins thylakoid membranes together, stroma is where chemical reactions occur for photosynthesis, granum, thylakoid membrane, thylakoid space.

Question 22

Light dependent reaction

Answer 22

Takes place in the grana and thylakoid membrane and results in the formation of NADPH and ATP
Chlorophyll absorbs light energy, chlorophyll becomes oxidised. Excited electrons move to a higher energy level- energy released helps activate the proton pump. Electrons move down ETC through a series of redox reactions. This pumps H+ ions, forming a proton gradient which moves through ATP synthase to combine ADP + Pi to form ATP. High energy electrons from the next chlorophyll reduces NADP to form NADPH. Photolysis- energy from light catalyses the breakdown of water forming 2H2O—> 4 protons, 4 electrons and O2. protons are used to help activate proton carrier and form a proton gradient. Electrons replace electrons lost from chlorophyll and reduce NADP.

Question 23

Chemiosmotic theory

Answer 23

The movement of ions across a ,membrane down an electrochemical gradient. This gradient is usually established through REDOX reactions and activation of proton pump.

Question 24

The light independent reaction

Answer 24

CO2 combines with RuBP, produces two GP molecules, 2GP reduced to 2 x Triose Phosphate, using reduced NADP and energy from ATP. Triose phosphate converted to glucose. RuBP reformed.
Fixation: RuBP is a CO2 acceptor, reaction is catalysed by rubisco.
reduction- gp is reduced to Triose phosphate, requires NADPH and ATP
Regeneration; Triose phosphate used to regenerate RuBP.

Question 25

Factors affecting photosynthesis

Answer 25

Temperature, CO2 concentration, light intensity and wavelength. Something else becomes the limiting factor for photosynthesis

Question 26

Concs of CO2 in the air at different heights above the ground in forest changes over a period of 24 hours. Explain why.

Answer 26

High conc of CO2 linked with darkness, no photosynthesis in the dark/ light dependent reaction, in dark plants respire, in light the rate of photosynthesis is greater than the rate of aerobic respiration. decrease in CO2 with height. At ground level there are fewer leaves.

Question 27

Commercial glasshouses

Answer 27

Enhance temperature, carbon dioxide concentration and light intensity. Manipulation of these factors increase productivity and produced high yields.

Question 28

Nucleus

Answer 28

Structure- nuclear envelope- double membrane and pores. chromosomes, nucleolus Function- site of DNA replication, production of mRNA, tRNA and rRNA. Stores genetic information for polypeptide production.

Question 29

Mitochondria

Answer 29

Double membrane, inner membrane highly folded to form cristae, matrix containing mitochondrial DNA, ribosomes, proteins and lipids Function- site of ATP production by aerobic respiration

Question 30

RER

Answer 30

Structure- highly folded membrane with 80s ribosomes, membrane folds to form flattened sacks called cisternae, joined to nucleus Function- synthesis and transport of proteins throughout the cell

Question 31

SER

Answer 31

Structure- highly folded membrane forming cisternae Function- recombines gylcerol and fatty acids to make triglycerides- site of lipid synthesis

Question 32

Cytoplasmic ribosome

Answer 32

Made up o 2 sub-units that are made of long strands of rRNA and ribosomal proteins Contains 80s cytoplasmic ribosomes in eukaryotes Function- sight of protein synthesis from amino acids

Question 33

Golgi

Answer 33

structure- flattened sacs of membrane filled with fluid, Golgi vesicles pinch off from the main membrane Function- sorts, modifies and packages proteins into vesicles, may be used to form ribosomes.

Question 34

Lysosomes

Answer 34

Structure- membrane bound organelle that stores and releases many hydrolytic enzymes Function- contains hydrolytic enzymes

Question 35

CSM

Answer 35

Made up of phospholipids Function- controls what enters and leaves the cell

Question 36

Centrioles

Answer 36

Structure- microtubules Function- form a network of spindle fibres onto which chromosomes attach

Question 37

Granum

Answer 37

Stacks of thylakoid membrane

Question 38

Thylakoid membrane

Answer 38

Contains chlorophyll for photosynthesis and ATP synthase enzyme to produce ATP

Question 39

Stroma

Answer 39

Fluid filled part, some of the photosynthesis reactions occur here

Question 40

Starch grains

Answer 40

Energy storing molecule

Question 41

Prokaryote

Answer 41

mesosome- highly folded section of the membrane. Plasmid, cell wall, cell membrane, capsule, flagellum.

Question 42

Centrifugation

Answer 42

Ice cold- reduce the action of enzymes that would digest or h=gazelles Isotonic- prevent osmosis of water in and out of organelles, so organelles don’t burst. Buffered- stop ph changes which could denature.

Question 43

Population

Answer 43

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

Question 44

carrying capacity

Answer 44

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 45

ecosystem

Answer 45

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

Question 46

why do two species not have exactly the same niche?

Answer 46

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

Question 47

what happens when niches overlap

Answer 47

species have adaptations that outcompete

Question 47

method of quadrating

Answer 47

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 47

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

Answer 47

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

Question 48

how to know when to stop quadrating

Answer 48

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 48

what rules are there for calculating an estimated population

Answer 48

not biased and random all data is reliable and representable

Question 48

quadrating

Answer 48

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 48

factors affecting distribution

Answer 48

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 49

systemic sampling

Answer 49

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 49

sere

Answer 49

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

Question 49

mark release recapture

Answer 49

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 49

pioneer species

Answer 49

the organisms that first colonise an area

Question 50

climax community

Answer 50

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

Question 51

diversity

Answer 51

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

Question 52

stages of succession

Answer 52

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 climac community is prevented from being established. community maintained under such conditions is known as a plagioclimax.