As YEAR 1 Biology Flashcards
State three differences between optical and electron microscopy
Optical uses light, electron uses electrons
Optical can look at living Samples, dead same
Optical has low resolution and magnification
What two stages are needed to prepare a large tissue specimen for light microscopy
Sectioning and staining
Many cells are colourless so details can not be see unless Stained
Name two pieces of equipment used to measure a cell under a light microscope and describe why one needs to be calibrated
Eyepiece graticule and stage micrometer
Objective lenses can have different levels of magnification
What is the difference between magnification and resoloution
Magnification increases how big an object seems whereas resoloutiom is how clear an image is
Define both rough ER and smooth
RER- thin,flattened sacs coated in ribosomes, synthesises and transports protein
SER-thin flattened sacs with many vesicles,synthesise,stores and transport lipids and carbohydrates
Define both lysosome and Golgi apparatus
Lysosome - small vesicles - secrete harmful enzymes out of the cell
Golgi apparatus - flattened sacs that bud into vesicles - modifies and packages proteins, sorts substances for secretion
Define ribosome and chloroplast
Ribosome - 2 subunits of RNA and small protein-protein synthesis
Chloroplast - double membrane, free DNA and thylakoid membrane - chlorophyll for photosynthesis
Name the organelle involved in
Cell division
Rapid movement of whole cell
Movement of contents outside of cell
Centrioles
Flagella
Cilia
What is a cytoskeleton
Give 2 uses of the cytoskeleton
Network of protein fibres, actin filaments and microtubules within the cytoplasm
Keeps cell shape stable
Provides mechanical strength
Describe the roles of organelles and structure in protein production and secretion
DNA from the nucleus codes for protein production on the ribosomes attached to the rough ER
Then transported in a vesicle to GA
Modifies and packages proteins
Another vesicle to cell membrane,fuses and released
Describe 2 properties of lipid in terms of energy release
Release more energy then carbohydrate
Used for long term energy storage
Describe three functions of lipids, especially important in cold water sea bird such as penguins
Buoyancy
Thermal insulation
Water proofing of feathers
Explain why some triglycerides do not form at room temperature
R groups with single bond between C atoms - saturated
R groups with double bonds between C atoms - unsaturated
Double bonds causes R groups to bend making them less compact, no solidify
How does the structure of cholesterol aid it’s function in cell membrane
Cholesterol have hydrophilic and hydrophilic ends that interact with phospholipid
Makes more rigid
What advantage does cholesterol based give these hormones
Can pass directly through the cell and reach their targets faster
Give a disadvantage of having excess cholesterol
Narrows blood vessels
What is an inorganic ion
Give example of an inorganic canion and anion
Inorganic Does not contain carbon
Ion - gained or lost an electron
Cation - hydrogen
Anion - chloride
What is a monomer
Small single unit
What is the different between the two polysaccharide of glycogen and cellulose
G- storage of glucose C- structurally in cell walls
G- alpha glucose C- beta glucose
Heavily branched
Long fibres
Name 3 parts of nucleotide
Pentose sugar
Inorganic phosphate group
Nitrogenous bass
What is the bond between pentose sugar and inorganic phosphate group
Phosphodiester bond
What nitrogenous base are purines and pyrimidines
Purines include adenine and guanine
Pyrimidines thymine,ucrail and cytosine
What are the 3 types of RNA
Messenger RNA
Transfer RNA
Ribosomal DNA
Describe the process of semi conservative replication
DNA helicase unwinds DNA strand,breaks hydrogen bonds
Free nucleotide,complementary base pair
DNA polymerase innate condensation reaction
State 4 different types of pathogen and give an example of each in humans
Fungi - athletes foot
Virus - HIV
Bacterium - Tuberculoses
Protoctist- Malaria
Define direct and indirect transmission and their modes
D- pathogen is transferred directly from one affected organism to another - contact and ingestion
ID-pathogen travels from one infected individual to another through the means of an unaffected object or organism.
Vectors and contaminated food and water sharing
State both structural and chemical defence in plant
Structural - callose deposition,bark,waxy cuticle, tough cell walls
Chemical - cell suicide,toxic substances,pathogen degrading enzymes
Why is it important to research plant response to disease
Better protect using chemicals and genetically engineer plants
That are important crops and sources for medicine
What statistical test is used do find whether the means are significantly different
Student T test
Describe how T lymphocytes and the two types of B lymphocytes provide a primary and secondary response to infection
T helper cells activate specific B cells which undergoes mitosis
B plasma cells release antibodies AAC
Pathogen immobilised for phagocytes to destroy
B memory cells remain in tissue to provide a rapid response
How do cytokines and opsonins differ
Cytokines is released by WBC to regulate overall immune response whereas opsonins is a signal molecule which binds on to pathogen to accelerate phagocytosis
What is an antibody
Cell membrane protein
Complementary shape to a specific antigen
What is agglutination
Antibodies bind onto pathogens , forming a structure that is too large to enter a cell
Describe the structured insects have to allow gas exchange
Spiracles - pores
Tracheae - tubes
TrachEOLES - small tubes
How do insects ventilate
Movement of thorax and abdomen
Changes body volume and forces gases in and out
Explain how aerobic respiration can be maintained in increasingly anaerobic conditions
Anaerobic conditions- increases lactic acid in muscle cells
Tracheal fluid in the ends of trachEOLES, contains water which enter muscle cells by osmosis because of concentration gradient lactic acid
Decrease in tracheal fluid more air into trachea
How do fish ventilate
Increase volume of buccal cavity to draw in waged, open and closes operculum over gills, maintains constant flow of water
What’s on a fish fill
LAMELLAE
Filaments
What is the name of process of gas exchange and why does it allow more oxygen to enter blood
Counter current flow
Blood and water flow in opposite directions
HOW HOB
What are enzymes
Globular proteins, biological catalyst
Lowers activation energy of metabolic reactions in living organisms
Give examples of both an intracellular and extra cellular enzyme
Extra - Amylase/lipase
Intra- DNA polymerase
What is activation energy
Energy required to trigger a chemical reaction
Describe what temperature coefficient(Q10) means
How the rate of reaction changes
With an increase of temperature by 10
Describe the use of co enzymes in enzymes mediated reactions
Small,non protein molecules
Bind to an enzyme at the same time as the substrate to facilitate the reaction
Describe the similarities and differences between co factors and prosthetic groups
Both bind to an enzyme to make the enzyme substrate complex easier.
Prosthetic binds permanently
Co factor- can move or attach to other substrate
What co factor is necessary for amylase functioning
What is the prosthetic group in carbonic anhydrase
Chloride ions
Zinc ions
What is the difference between a competitive and non competitive inhibitor
Competitive inhibitors binds on to the enzymes active site whereas non competitive binds elsewhere on to the enzymes but alters the structure, so enzyme active site no longer complementary
Briefly outline how an irreversible inhibitor affects the structure and function of
an enzyme.
Causes a permanent change to the enzyme’s active site so the enzyme is inactivated / cannot function
What are the properties of molecules that can freely diffuse through the cell membrane
Small
Uncharged
Lipid soluble
What is the difference between simple and facilitated diffusion
Facilitated diffusion require carrier or channel proteins because the molecules are too big
Simple diffusion does not need any membrane proteins
What kind of transport are endocytosis and exocytosis used for
Bulk transport
Describe the 3 different levels of biodiversity
Habitat- diversity of habitat
Species - richness and evenness
Genetic - diversity between individuals within the same species
Describe 2 ways farmers could help conserve wildlife
Decrease the use of artificial chemicals
Provide alternative habitats
Give an example of a conservation agreement that protects wildlife
Countryside stewardship scheme
Suggest three ways in which students could improve validity of their sampling method
Same tree
Size leaves
Systematic sampling
What processes occur during translocation
Hydrogen ions out of companion cell - AT
Sucrose into companion cell - FD
Sucrose out of companion cell - diffusion
Describe the structures of sieve tubes and companion cells
Sieve tubes - elongated cells that line up to form tubes with a thin cytoplasm, they form phloem and allow the flow of sap
Companion cells - contain many mitochondria to produce ATP
Describe the theory involved in water transport of the xylem
Cohesion tension theory
Dependent on the transpiration in the leaves
Water evaporate out of stomata to more negative water potential
Water molecules held by hydrogen bonds, stream of water molecule pull upwards
Describe the pathway of water from absorption by the roots to entering the xylem
AT of minerals to roots, lower WP, so water moves via osmosis
Travels to endodermis till meets casparian strip, force for take symplast pathway
What is the difference between the the apoplast and symplast pathway
A- between the cells and cell walls
Symplast - cytoplasm and plasmodesmata
What are xerophytes
3 adaptation
Planes adapted to live in dry conditions
Small SA
stomata cells closes when there is low water availability
Hair on surface to trap moisture
Explain why the type of nuclear division on zygotes is mitosis and meiosis
Mitosis is the stage of growth and production of 2 genetically identical daughter cells
Explain the role of embryonic stem cells in the development of the embryo
Unspecialised cells ready to be differentiate into any cell type
explain why the cells of the inner cell mass are not totipotent stem cells
Can not form whole organism
Describe and explain why collagen is a fibrous protein
Long chain
Insoluble because it has many non polar amino acid
Play a structural role
Long polypeptide chains with many hydrogen bonds between polypeptide
Describe the structure of the rough endoplasmic reticulum
And the role of the membrane
Molecules form a phospholipid bilayer, flattened sacs and covered in ribosomes
Hold the ribosomes in place
Barrier between organelle between cytoplasm for specific metabolic reaction
Explain how the nucleotides in a DNA molecule are arranged as two polynucleotide strands
nucleotides joined by phosphodiester bonds
2 hydrogen bonds between, complementary / named bases
Explain why the type of nuclear division on zygotes in mitosis and not meiosis
Mitosis is the stage of growth and production of 2 genetically identical daughter cells
Explain the role of embryonic stem cells in the development of the embryo
Unspecialised cells ready to be differentiate into any cell type
Explain why the cells of the inner cell mass are not totipotent stem cells
Can not form the whole organism
Describe the structure of RER
And role of membrane
Molecules form a phospholipid bi layer
