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AS Biology > Biodiversity and Natural Resources > Flashcards

Biodiversity and Natural Resources Flashcards

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1
Q

3 types of adaptation

A

behavioural
anatomical
physiological

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2
Q

define behavioural adaptation

A

actions by organism

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3
Q

define anatomical adaptation

A

observed structures of organism

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4
Q

define physiological adaptation

A

internal workings of organism

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5
Q

define allele frequency

A

number between 0-1 showing proportion of an allele within a population

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6
Q

define evolution

A

change in allele frequency over time

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7
Q

define natural selection

A

process by which evolution happens

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8
Q

1st step of natural selection

A

genetic variation due to random mutations (creates new alleles)

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9
Q

2nd step of natural selection

A

sexual reproduction creates new allele combinations

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10
Q

3rd step of natural selection

A

environmental change creates a selection pressure giving advantageous phenotype a competitive advantage

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11
Q

4th step of natural selection

A

individuals with advantageous phenotype are more likely to survive and reproduce passing on advantageous alleles
(alters allele frequency)

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12
Q

factors for rate of change in allele frequency

A

strength of selection pressure
size of gene pool
organisms’ reproductive rate

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13
Q

importance of variation

A

population is more resistant to environmental condition changes

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14
Q

ways allele frequency can cgange

A

natural selection- caused by selection pressure
sexual selection- caused by mating preferences
gene flow- caused by migration
genetic drift- caused by chance

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15
Q

rules for the Hardy-Weinberg principle

A

no selection pressure
no migration
no mutations
random mating
large population

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16
Q

what does the Hardy-Weinberg principle apply to

A

genes with 2 alleles- 1 dominant and 1 recessive

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17
Q

Hardy-Weinberg principle equations

A

p + q = 1
p^2 + 2pq + q^2 = 1

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18
Q

what does p^2 represent

A

homozygous dominant frequency

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19
Q

what does q^2 represent

A

homozygous recessive frequency

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20
Q

what does 2pq represent

A

heterozygous frequency

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21
Q

5 kingdoms

A

animals
plants
fungi
protists
prokaryotes

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22
Q

3 domains

A

eukaryotes
archaea
bacteria

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23
Q

classification order

A

kingdom
phylum
class
order
genus
species

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24
Q

define molecular phylogeny

A

study of the similarities and differences in DNA/RNA base sequences and/or amino acid sequences in proteins to determine evolutionary relationships between organisms

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25
how did molecular phylogeny provide evidence for the 3 domains
showed the 4 eukaryote are closer evolutionary than types of prokaryotes
26
plant adaptations
support- xylem and sclerenchyma chemical defence seed production
27
human uses of plants
fibres eg: fabrics medicines cosmetics food
28
structure and function of cell wall
made from cellulose contains pits and middle lamella strength and support
29
what are pits
thin sections of the cell wall
30
vacuole
filled with water ions and sugars single membrane (tonoplast) keeps cell turgid
31
structure and function of chloroplasts
double membrane contain fluid contain circular DNA photosynthesis
32
name of chloroplast internal membrane
thykaloid
33
name of chloroplast fluid
stroma
34
structure and function of amyloplasts
double membrane store amylopectin
35
difference between plasma membrane in animals and plants
continuous in plant cells (plasmodesmata)
36
structure of cellulose
unbranched, straight chains of beta glucose (microfibrils) lattice structure due to hydrogen bonds between chains
37
properties of cellulose
insoluble strong hard to digest high tensile strength (hard to stretch)
38
define microfibrils
bundles of beta glucose chains
39
why is cellulose strong
microfibrils laid parallel or at different angles pectin and hemicelluloses (short-chained polysaccharides) embedded in fibres
40
Structure of xylem
Lignified (waterproof) Pits (allow water leak) Hollow tubes Open ends Dead tissue
41
Function of xylem
Water and mineral transport (transpiration)
42
Structure of sclerenchyma
Lignified Small lumen Thick walls Closed ends (no transport) Elongated dead cells
43
Function of sclerenchyma
Support and protection
44
Structure of cambium cells
Undifferentiated Between xylem and phloem
45
Function of cambium
Able to specialise as plants grow
46
Function of parenchyma cells
Act as packing between other cells (pith)
47
Define transpiration
Loss of water from leaves
48
Factors of transpiration
Temperature Light level Wind speed Humidity
49
How does temperature affect transportation
Higher temperature, higher transpiration rate Water evaporates faster
50
How does light level affect transportation
Higher light intensity, higher transpiration rate More open stomata letting water out
51
How does wind speed affect transportation
Higher wind speed, faster transpiration rate Removes water Vapor from leaves faster
52
How does humidity affect transportation
Higher humidity, slower transpiration rate Decreased concentration gradient
53
What makes water a good transport molecule
Liquid at room temperature High SHC (strong intermolecular forces) Effective solvent (polar)
54
3 pathways for transpiration
Apoplast (cell walls) Symplastic (osmosis through cytoplasm) Transmembrane (mix of both)
55
56
What’s the casparian strip
Waxy material preventing in useful substances entering xylem Forces symplastic route
57
Define xerophytes
Plants adapted to reduce transpiration rates
58
Describe the cohesion tension theory
Water molecules arrange so opposite poles are adjacent Causing theme to cohere
59
First step of transpiration
Water moves across a leave down diffusion gradient causing Water drawn into root hair cells via osmosis
60
Second step of transpiration
Evaporations of water lowers hydrostatic pressure of water in leaf
61
Third step of transpiration
Water moves from an area of more free water molecule across semi permisible membrane into area of fewer free water molecules
62
Fourth step of transpiration
Water evaporates from stomata down diffusion gradient
63
Fifth step of transpiration
Water molecules move across root cells down water diffusion gradient
64
Sixth step of transpiration
Water moves up xylem due to water evaporation of leaf surface aided by cohesion and adhesion
65
Seventh step of transpiration
Water enters xylem (transpiration system)
66
Adorations in environments with little water
Thick waxy cuticle (minimise water loss) Few stomata (prevent photosynthesis)
67
Impacts of nítrate deficiency
Stunted growth (makes DNA) Yellow leaves (makes chlorophyll)
68
Impacts of magnesium oil deficiency
Yellow leaves (makes chlorophyll and activates enzymes)
69
Impacts of calcium ion deficiency
Stunted growth (calcium percate holds plant cells together)
70
How is species diversity measured
Species richness Species evenness
71
Formula for diversity index
N(N-1) / sun of n(n-1) N- total no. Organisms if all species n- total no. Organisms of a particular species
72
Define dormancy
Mechanism to delay germination
73
Define germination
First root and shoot sprout from a seed
74
Define viable
Able to germinate in the correct conditions
75
How are seeds collected for seed banks and why
Collected from many different plants Maintains genetic diversity
76
What happens to seeds at a seed bank
Checked for contamination with pests X-rayed to check for formed embryos Dried to stop enzymes working (no germination)
77
What conditions are seeds stored in seed banks
Coke and dry
78
Describe germination trials
Check for seed viability (decreases over time) When germination % is too low the seeds are regrown to produce new seeds to store
79
Define inbreeding depression
Breeding closely related animals increasing the chance of a homozygous recessive genotype
80
Impacts of inbreeding depression
homozygous genotype often harmful and cause genetic diseases
81
How do captive breeding programs reduce inbreeding depression
Stud books (control partner choice) Transfer animals/ speeds to other zoos Avoid close leg related animals breeding
82
Factors of successful reintroduction
Intact native habitat with sufficient resources Individuals have the necessary skills to survive in the wild Successful captive breeding to increase population numbers
83

AS Biology (4 decks)

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