Topic 4: Biodiversity and Natural Resources Part 1 Flashcards

Question

explain speciation

Answer 1

- occurs when populations of a species are split by an isolation mechanism - there are now 2 reproductively isolated populations of one species - so there is no genetic change between them - sufficient selection pressures acting to change the gene pools and allele frequencies within both populations will allow the 2 populations to eventually diverge and form different species - a change in alleles and gene pools influences phenotype which will cause them to differ physiologically, behaviourally and anatomically over time

Answer 2

the evolution of new species as a result of geographical isolation, features like mountains, rivers and lakes can separate populations and the feature acts as a barrier to gene flow in the population

Answer 3

evolution that occurs while the populations inhabit the same geographical location as a result of reproductive isolation because of mutations changing certain characteristics

Answer 4

1. seasonal changes; individuals from the same population can develop different flowering/mating seasons or may become sexually active at different times of year 2. mechanical changes; changes in genitalia prevent successful mating 3. behavioural changes; a group of individuals develop courtship rituals that aren't attractive to the main population

Answer 5

the science of classification, organisms are named and put into groups based on similarities and differences, making it easier for scientists to identify and study them

Answer 6

the first name is the Genus of the organism; it's the general one the second name is the Species of the organism; its the specific name I allows scientists to agree universally on the names of organisms the genus depicts more similarity than the species

Answer 7

kingdom phylum class order family genus species

Answer 8

a series of nested groups/taxa in which the members all share 1 or more common features, or homologies it is based on phenotype (king prawn curry)

Answer 9

organisms can superficially look similar and not be closely related, they only look similar because they've adapted to similar conditions

Answer 10

a newer classification system based on molecular phylogeny; it included **archaea, bacteria and eukarya** molecular phylogeny relies on similarities/differences of DNA and amino acid sequences between groups of organisms to determine how closely they're related the more similar the molecules, the more closely they are related it provides more evolutionary evidence by analysing common genome amino acid sequences

Answer 11

prokaryotae protoctista fungi plantae animalia

Answer 12

eg. bacteria they are prokaryotes and are unicellular with no nucleus usually <5μm

Answer 13

eg. algae, protozoa eukaryotic cells that don't fit in the other kingdoms so there's variation usually in water, can be single celled/simple multicellular organisms

Answer 14

eg. moulds, yeasts, mushrooms eukaryotic, chitin cell wall, saptrotrophic (absorb substances from dead/decaying organisms)

Answer 15

eg. mosses, ferns, flowering plants eukaryotic, multicellular, cellulose cell wall, able to photosynthesise, contain chlorophyll, autotrophic (produce their own food)

Answer 16

eg. nematodes, molluscs, insects, fish, reptiles, birds, mammals eukaryotes, multicellular, no cell walls, heterotrophic (consume plants and animals)

Answer 17

in situ is ideal, it protects ecosystems and maintains fragile habitats ex situ is when vulnerable populations in the wild are supported through the work of zoos and seedbanks

Answer 18

**carry out scientific research** - it can be in the zoo or on expeditions to an animals natural habitat to help inform conservation **captive breeding programmes** - they aim to increase the no. of individuals in the species if numbers are low, maintain genetic diversity in the captive population and reintroduce animals into the wild if possible zoos share animals and use IVF to prevent small gene pools (keep studbooks to log info) **reintroduction programmes** **education programmes** - promote endangered species, raise conservation funds, change human behaviours, share expertise **studbooks** log which zoo animals are at and who they are related to to prevent inbreeding and maintain/increase the genetic pool

Answer 19

store seeds from various endangered plants to help conserve biodiversity in case of extinction store a range of seeds from different seeds bc they have different alleles stored in cold and dry conditions, seeds have to be tested for viability (their ability to grow into a plant), seeds are planted and grown and new seeds are harvested to put back into storage

Answer 20

+ storing seeds is cheaper than fully grown plants + more can be stored than plants + less labour used than with plants + can be stored anywhere cool and dry, plants would need their original habitat + seeds are less likely to be damaged by disease, natural disaster or vandalism -- can be expensive and time consuming to test for viability -- it would be too expensive to store all types of seed and test them for viability regularly -- some plants may grow in remote places, making seed collection difficult

Answer 21

1. ensure protection of the embryo 2. aid dispersal 3. provide nutrition for the new plant

Answer 22

the seed takes in water through a small pore in the seed coat absorbing water triggers a metabolic change in the seed and enzymes that mobilise stored food reserves are produced maltase and amylase break starch down to glucose which is converted to sucrose for transport to the radicle (young root) and plumule (young shoot) proteases break protein down to amino acids lipases break stored lipids down into glycerol and fatty acids

Answer 23

thickening - heating starch granules in water makes them suddenly swell, absorb water and thicken the liquid; this is gelatinisation and is used in custard and wallpaper paste stiffening fabrics - sizing is the stiffening of cloth/paper, its used very often and done by applying a starch mixture to the surface which is gelatinised and cooled, allowing bonds to form between the starch molecules. adding water reverses the stiffening (plasticisation) and this allows the shape to be changed super-absorbents - chemically cross linking starch before gelatinisation forms particles which can be dried and rehydrated so that they can take up large amounts of water and can be found in nappies starch foam - the more water in the starch mix, the lower the gelatinisation temperature will be; raising the pressure at the same time makes the starch form a plastic mass and then releasing the pressure suddenly will form steam and make the starch puff into an expanded structure; this technique is used to make foam packaging

Answer 24

its a rigid structure that surrounds plant cells, it is mainly made of the carbohydrate cellulose it supports plant cells

Answer 25

it is the outermost cell layer it acts as an adhesive and sticks adjacent plant cells together, giving the plant stability

Answer 26

they are channels in cell walls that link adjacent cells together a cytoplasmic connection between cells they allow communication and transport of substances between cells

Answer 27

regions of the cell wall where it is very thin, they're arranged in pairs meaning that the pit in one cell is lined up with the adjacent cell's pit allows substabc transport between cells

Answer 28

it is a small, flattened structure that is surrounded by a double membrane and thylakoid membranes are stacked to form grana, these are linked together by lamellae which are thin, flat pieces of thylakoid membrane the many layers increase surface area to absorb light they contain chlorophyll to absorb light they have electron carrier molecules in the thylakoid molecules for ATP production it is the site of photosynthesis, some of it occurs in the grana and some occurs in the stroma, which is a thick fluid found in chloroplasts

Answer 29

it is a small organelle enclosed by a membrane, they contain starch granules stores starch grain and converts starch back into glucose for release when requires by the plant

Answer 30

the vacuole is a compartment surrounded by a membrane called the tonoplast vacuole contains: the cell sap (which is made of water), enzymes, minerals and waste products vacuoles keep the cell turgid, preventing the wilting of plants and are involved in the breakdown and isolation of unwanted chemicals in the cell the tonoplast controls what enters and leaves the vacuole

Answer 31

it is the main energy storage molecule in plants; excess glucose is stored as starch in chloroplasts and amyloplasts starch is made of2 a-glucose polysaccharides: amylose + amylopectin amylose - long, unbranched chain, 1-4 glycosidic bonds angle give it a coiled structure, making it compact and good for storage amylopectin - a long, branched a-glucose chain, 1-4 and 1-6 glycosidic bonds leave a branched molecule so many terminal glucose molecules that can be easily hydrolysed for respiration and added to for storage

Answer 32

ABBA alpha below, beta above in reference to the CH2OH side chain | add pic?

Answer 33

it is a polysaccharide and the main component of plant cell walls it is made of long, unbranched, ß-glucose chains that are joined by 1-4 glycosidic bonds (each ß-glucose is inverted 180˚to allow these bonds to form; the bonds are straight so the cellulose chains are straight 50-80 cellulose chains are linked together with hydrogen bonds between cellulose chains, to form strong threads known as microfibrils, these allow cellulose to provide structural support for cells

Answer 34

- both are glucose - one is a beta-glucose polysaccharide and the other is alpha-glucose - starch is an energy storage molecule and cellulose is a structural molecule of plant cell walls - starch has alpha-1,4 and alpha-1,6 glycosidic bonds, cellulose has ß-1,4 glycosidic bonds - starch is made of branched and unbranched glucose, cellulose is made of only unbranched glucose - cellulose is stronger than starch

Answer 35

1. make up 3 nutrient broths, each with a different concentration of calcium ions; high, medium and low 2. split 9 test tubes into 3 groups and fill the tubes of each group with one of the broths 3. take 9 seedlings of the same plant and measure and record the mass of each. place into the top of a test tube so that the root is suspended in the nutrient broth, support the. seedling using cotton wool in the tube's opening 4. cover the outside of each test tube in aluminium foil so that light can't get to the broth and cause the growth of other organisms like algae 5. place them all near the same light source, a windowsill and leave for the same amount of time, 2 weeks. top up the nutrient broths when necessary to keep the roots suspended 6. remove each plant gently and blot dry, measure and record the new mass and calculate the mean change in mass for each nutrient broth; also note down visual differences between groups

Answer 36

they help indicate uncertainty and how precise a measurement is a short error bar means the values are concentrated and a long one means that they are more spread out and are less reliable skewed data will make the bars inequal; they won't be the same length above and below an overlap in error bars means that the difference is significant they can represent standard deviation PCITURE

Answer 37

choose seeds from various plants in a species to provide genetic variation X-ray the seeds to check for viable embryos

Answer 38

transpiration is the water loss from leaves by evaporation 1. water moves up the xylem bc of a hydrostatic pressure difference (lower at top), this lowers hydrostatic pressure in the root, so water constantly diffuses from the root tissues and the soil 2. movement of water from soil to plant = transpiration stream 3. the column of water being pulled up the xylem is prevented by falling from gravity because of upward pull + adhesion forces between lignin and water 4. the pull plus adhesion to wall puts water columns in the xylem under tensions so they’re stretched; cohesion-tension theory of water transport 5. water potential of cells in the leaf is lowered by water leaving, so a gradient of water potential is created that draws water from the xylem in the leaf veins (cohesion??) water can diffuse from cell to cell, via the plasmodesmata or in the cell walls 6. water vapour diffuses through air spaces in the leaf and out of the stomata, down the diffusion gradient (transpiration) 7. leaf absorbs heat energy from sun and water evaporates constantly from leaf cell’s cell walls

Answer 39

apoplastic route - moves within porous cell walls - water moves passively and freely through the cellulose walls of cells as a result of the cohesion tension that transpiration creates; cohesive forces between water molecules ensure that water is drawn from across adjacent cell walls symplastic route - through the plasmodesmata and cytoplasm - water diffuses along water potential gradient through the cytoplasm of adjacent cells and plasmodesmata

Answer 40

**function** transport water and mineral ions up the plant, provide support **structure** - very long, tube-like structures formed from dead cells joined end to end, found together in bundles - longer than width with a hollow lumen, no cytoplasm and no end walls; forms an uninterrupted tube - walls are thickened with lignin, which helps to support the plant - the walls have pits where there’s no lignin water and mineral ions move in and out of the vessels here pictyre

Answer 41

function - provide support made of bundles of dead cells, running vertically up the cell cells are longer than wide, have a hollow lumen and have end walls cells are thickened with lignin with No pits, they have more cellulose than other plant cells pciyre

Answer 42

function - transporting organic solutes from where the plant makes them to where they’re needed; translocation it is purely a transport tissue (not involved in support) contains sieve tube elements and companion cells (different cell types) sieve tube elements - living cells joined end to end to form sieve tubes they are the end walls, the solute can pass through the many holes - unlike most living cells; sieve tube elements have no nucleus, a very thin cytoplasm layer and few organelles - this means they can’t survive alone, so there is a companion cell for every sieve tube element - the cytoplasm of adjacent cells is connected through sieve plate holes companion cells - carry out living functions in sieve and themselves, eg. provide energy for solute active transport

Answer 43

translocation moves dissolved substances like sucrose and amino acids from where the substance is made (the source) in the plant to where it is needed (the sink) it occurs in the phloem and is an active process that requires energy

Answer 44

* waxy cuticle is impermeable to water loss * stomata are on the underside of the leaf where it’s cooler * thick leaves reduce water loss * spines/hair increases the boundary layer (undisturbed air layer) * stomata close at certain times of day * stomata may be sunken and found in pits`

Answer 45

tensile strength = force/cross-sectional area measure diameter using callipers 1. attach the fibre to a clamp stand and hang a weight on the other end 2. keep adding weights in regular intervals until the fibre breaks 3. record the mass needed to break the fibre - the higher the mass, the higher the tensile strength 4. repeat with different samples of the same fibre to calculate the mean and reduce random error 5. calculate tensile strength controls: length of fibre temperature humidity safety: wear goggles for eye protection don't stand where toes will get squashed by weights

Answer 46

p + q = 1 (frequency of all alleles) p^2 + 2pq + q^2 = 1 (frequency of all genotypes) p = dominant, q = recessive you generally have to use the genotype equation first

Answer 47

cold and dry

Answer 48

a change to a DNA base sequence that may result in a change in the amino acid sequence and thus, different alleles forming

Answer 49

DEFINE!!!!

Answer 50

- compare DNA sequences - compare amino acid sequences - compare mRNA sequences - see if they breed to form fertile offspring

Answer 51

1. mutations result in new alleles forming 2. selection pressures can make the alleles advantageous 3. more individuals with advantageous alleles survive and reproduce 4. over time the population would no longer be able to reproduce with the other population to form fertile offspring

Answer 52

xylem: inner side of vascular bundle phloem: middle of vascular bundle schlerenchyma: outer side of vascular bundle

Answer 53

measure biodiversity using a diversity index, higher index means greater biodiversity assess species richness assess genetic diversity of the species present assess whether any endemic/rare species are present

Answer 54

by active transport through carrier proteins, requiring ATP

Answer 55

A CHANGE In THE SEQUENCE OF BASES IN DNA —> CHANGE IN AMINO ACID SEQUENCE —> different r groups and diff bonds and folding

Answer 56

that species is extinct! the loss of them will significantly reduce biodiversity

Answer 57

reproductive isolation due to: physio anatomical beh. etc

Topic 4: Biodiversity and Natural Resources Part 1 Flashcards

(86 cards)