exam Q's Flashcards
describe how cytokine molecules can stimulate specific groups of B lymphocytes to divide?
-cytokine has specific shape
-binds to the receptor
-receptor on cell surface membrane of b lymphocyte
-receptor has complimentary shape
-activates clonal expansion
describe the role of memory cells when the influenza virus enters the body
-recognise virus/antigen
-clonal expansion
-can change to form plasma cells
-make antibodies
-responsible for secondary response
plasmodium is described as a parasite
define the term parasite
lives , in / on , host ;
gains nutrition / feeds , from (host) ;
at the expense of / harms (host) ;
ACCEPT causes disease
the symptoms of malaria are caused by a single celled organism belonging to the genus Plasmodium
explain why the human body primary defences do not prevent plasmodium from entering the body
mosquito / vector / Anopheles , feeds on blood ;
breaks skin / skin cannot act as barrier / mosquito pierces
skin / mosquito bites skin ;
In patients with IDA anemmia is caused by destruction of red blood cells by phagocytosis
suggest why red blood cells that contain plasmodium are more likely to be destroyed than healthy red blood cells
chemicals that attract phagocytes (released from
infected erythrocytes) ;
ACCEPT cytokines / histamine / interleukin , released
describe how the structure of antibodies allow them to perform their function
variable region allows , binding / attachment , to
antigen ;
two variable regions allow binding of more than
one (of the same) antigen ;
variable region on different antibodies allows specificity
to different antigens ;
constant region allows , recognition by / attachment to /
binding to , (named) phagocytes ;
hinge (region) allows flexibility ;
disulfide , bonds / bridges , hold , polypeptides / light
and heavy chains , together ;
explain neutralisation by antibodies
cover / block , binding site / antigen / receptor site (on
pathogen) ;
bind to toxins ;
prevent , binding / entry , to (host) cell ;
why is this statement incorrect; bacteria can evolve quickly and many are now immune to antibiotics
immunity involves / bacteria do not have , lymphocytes /
white blood cells / antibodies / memory cells /
plasma cells / an immune system ;
(correct term is) resistant ;
bacteria are unicellular / only multicellular organisms
(can) have an immune response;
outline a valid plan that could be used to investigate the effect of temperature on callose production in plants
-range of temperatures (0, 10, 20, 30, 40 degrees)
-suitable sample size and taking repeats e.g. 50 plants
-baseline measure of callose levels before the experiment
-using clones of plants as a control variable = genetically identical
-control same pH, nutrient level
-observe callose using a microscope, take tissue samples, standardize the size and location of tissue samples
-use a stain e.g aniline blue
suggest two ways aromatic resin frankincense which can harden to cover a wound, contributes to defending the tree from a pathogen
-aromatic compound is antibacterial
-prevents pathogen from entering the wound
state the role of cytokines in phagocytosis
-attracts phagocytes
explain why toxins produced by different strains are described as being immunologically distinct and how they will be dealt with by the immune system
-toxins produced by each strain will be slightly different
-each toxin will have different 3D shape/ amino acid sequence
-toxin acts as antigen = immune response determined by the shape of the antigen
-APCs ingest antigen and display antigen on their surfaces
-interactions between APCs and t-helper cells causes production of of interleukins
–b cells activated by T helper cells = clonal selection and expansion
-plasma cells differentiate into plasma cell
-by protein synthesis antibodies bind to and neutralise toxins
using examples, explain how both genes and environment can cause animals to vary in their specific immune response
genes:
-inherit genes that code for immune cells/ antibodies from parents e.g B/T lymphocytes, macrophages,
-different alleles code for many different versions of immune cells/ antibodies
-alleles code for different variable regions
-autoimmune diseases such as arthiritis
environmental
-exposure to different pathogens determines immune response e.g measels= memory cells
-vaccination produce primary immune responses
-poor diet can weaken immune system e.g low levels of protein= reducing antibodies
explain how memory cells cause different responses
-memory cells remain in blood after primary response
-so faster clonal selection
-memory cells not active in primary response
