Cellular Defence Flashcards
What is the role of phagocytes
To flow around foreign particles and engulf them in a vacuole
What do phagocytes contain and what is their job
Lysosomes and they digest foreign particles
What do lymphocytes do
They produce antibodies that are specific To antigens and the antibodies combine with the antigens to render it harmless
What does resin do
It produces a barrier which prevents entry to pathogens and viruses Such as a coat of resin which seals the intruder
What are some toxic chemicals plants may produce in response to intruders
Tannins, cyanide and nicotine
At the end of meiosis what is each set of chromosomes said to be
Haploid
What are 2 ways of increasing variation within a species
Independent assortment and crossing at the chiasma
What are the stages of viral replication
Attachment, penetration, viral nucleic acid is injected and replicates, virus components are produced, assembly and release
Give an example of a mutagenic agent
Mustard gas, UV light, radiation from x-Rays
What is non-disjunction
Where the homologous pair of chromosomes are seperated at either sides of the cell and where there is a loss of a chromosome or an extra chromosome added on e.g Down’s syndrome (21 chromosomes)
What is polyploidy
Where homologous chromosomes seperate during first division in meiosis and produce gametes or 2 full sets of chromosomes
What is the advantages of polyploidy in plants
Increased vigour, meaning increased crop yeilds and increase resistance to disease
When a chromosome breaks in 2 places and rejoins with a section missed out it is called
Deletion
When a chromosome breaks in 2 and rejoins with a section the wrong way about this is
Inversion
When a chromosome is broken and seperated section is joined to another chromosome this is
Translocation
