SEARCH
You are in browse mode. You must login to use MEMORY

   Log in to start

level: Resources from Plants

Questions and Answers List

level questions: Resources from Plants

QuestionAnswer
ultrastructure of plant cellscell wall chloroplasts amyloplasts vacuole tonoplasts plasmodesmata pits middle lamellae nucleus
cell wall in plant cellsmade of cellulose made up of middle lamellae which is made of calcium pectate provides structure, support and shape to the plant cell
chloroplastssite of photosynthesis contain stacks of thylakoid called grana which contain chlorophyll
amyloplastsorganelles surrounded by a double membrane which contain amylopectin stores starch
vacuolecontains cell sap surrounded by a tonoplast (single membrane) provides structure and support to the cell also helps maintain water balance
tonoplastscytoplasmic membrane that surrounds the vacuole regulates the movement of substances around the cell isolates harmful material
plasmodesmataextension of the cytoplasm between adjacent cell walls it is involved in the transport of substances between cells
pitsdepressions (holes) in the cell wall act as channels for water and mineral transport between adjacent cells
middle lamellaelayer that cements two neighbouring plant cells together made up of calcium and magnesium pectates
how does the structure of starch relate to its function?insoluble - no osmotic effect branched - can be easily broken down compact - so can be stored in large amounts
features and function of cellulosemain structural component of plant cell walls high tensile strength made up of beta glucose only contains 1-4 glycosidic bonds forms microfibrils which are joined by hydrogen bonds (occurs between OH groups) alternating pattern of inverted glucose molecules straight and unbranched
why are plant fibres useful to humans?sustainable renewable resource biodegradable they are very strong - make ropes and fabrics cheaper than oil-based products starch can be used to make bioplastics and bioethanol
sclerenchyma fibreslignified made of dead cells has a hollow lumen and end walls provides structural support to the plant
xylem vesselstransport water and minerals provide structural support to the plant lignified made of dead tissue
phloem vesselstransport nutrients and food substances involved in translocation made of living cells made up of sieve tube elements and companion cells
importance of nitrate ions in plantsmakes up amino acids which make proteins also make up DNA and RNA nucleotides
importance of calcium ions in plantsmake up the plant cell wall form calcium pectate
importance of magnesium ions in plantsinvolved in chlorophyll production activate some plant enzymes
importance of water in plantsimportant for photosynthesis maintains plant structure transports substances thermoregulation
investigate plant mineral deficienciesplant seedlings - same age, same source nutrient broths each lacking a mineral cover test tube with foil to prevent light entering experiment occurs over a week so some change is observed same temperature, same light intensity, same volume of nutrient broth used
lack of nitrate ionsstunted growth, yellow leaves, dead leaves
lack of calcium ionsstunted growth, yellow crinkly leaves, dead leaves
lack of magnesium ionsslowed growth, yellow leaves
determine the tensile strength of plant fibressource of fibre should be soaked to allow easy extraction of the fibres attach fibre to clamp and hook to other end of fibre add weights to the hook gradually until fibre breaks record weight fibre broke at repeat this for different fibres obtained many times to find the mean averages
describe William Withering's drug testpotential substance identified but not as a single active ingredient trial on small group of patients with the disease large group of patients trial also with the disease dosage refined and method of extraction improved general use
differences between modern drug testing and Withering's testingpreclinical trials use of animals placebo used double blind trial more ethical proper approval of use of drug healthy volunteers used
investigate the antimicrobial properties of plants including aseptic techniquesgrind some garlic or mint in a mortat and pestle squeeze out the juice with muslin soak small paper disk into the garlic/mint solution for 20 mins heat forceps on a bunsen burner to get rid of excess bacteria use forceps to place a garlic/mint disk into agar plate of e.coli use disk soaked in distilled water for control incubate e.coli at 25 degrees for a few days measure the diameter of each clear zone repeat to calculate mean
conservationpreventing the extinction of critically endangered organisms
genetic diversitythe total number of genetic characteristics in the genetic makeup of a species
role of zoosconservation research education
methods used for conservationstudbooks captive breeding programme seedbanks reintroduction into the wild
captive breeding programmeendangered animals are captured and taken into zoos zoos encourage breeding between species of captured animals to increase the population once the population is sufficient animals are reintroduced back into the wild risk of genetic drift
genetic driftwhen in a small population allele frequency changes due to a chance event
why is genetic drift bad?reduces genetic diversity weaker organism so more likely to die population reduces as a result
seed banksseeds placed in low temp, dry conditions to stop growth periodically tested for viability conserves genetic diverstiy