topic 4B - diversity, classification and variation Flashcards
(18 cards)
what is a mutation?
a change in the sequence of bases in a gene/chromosome, or a change in the structure of the chromosome (which changes the arrangement of genes)
when do mutations occur?
randomly or mutagens e.g. tar in the lungs, UV radiation and mustard gas.
what are types of mutations?
1) a silent mutations - occurs when substitution of a base still codes for the same amino acid as the original base due to possible denature of the genetic code. this would have no effect on the final production of the final polypeptide.
2) a mis-sense mutation - occurs when a change in base leads to a different amino acid being coded for. the polypeptide will have a single amino acid that is different
what is courtship behavior?
act carried out by an organism to attract a mate of the right species and opposite sex
what are types of courtship behavior?
1) pheromones - releasing chemical signals e.g. male bumble bee
2) sounds - e.g. male red deer roars to attract females
3) visual displays - e.g. male peacock display tail feathers
what does courtship behavior allow animals to do and why is it important?
1) recognize their own species
2) approach each other
3) choose a strong and healthy mate
4) form a pair bond and synchronize breeding behavior
its important because:
- species recognition (e.g. sight, sound or smell)
- avoiding aggression
how does courtship affect classification?
what is classification?
the organization of living things into groups according to their genetic similarities
what is species?
a group of organisms that are similar to each other, and breed to produce fertile offspring. that occupy the same ecological niche and that belong to the same gene pull.
what is the lannaen system?
two names
1) (upper case) the generic name (genus) like a surname so closely related species share this (first name)
2) (lower case) specific name (the species) like a first name (not shared by any other species) (second name)
what is taxonomy?
classifying organisms into groups
what is hierarchy?
groups within groups, with no over lap
where do mutations happen and what happens to them?
happen at the gametes and somatic cells (body cells).
faulty DNA can be repaired by specific enzymes.
unrepaired mutations will affect the new proteins being synthesized
define truncated
short protein
what’s a nonsense mutation?
A nonsense mutation occurs in DNA when a sequence change gives rise to a stop codon rather than a codon specifying an amino acid.
why can random mutations forming new alleles be harmful and beneficial?
harmful: mutated gene quickly dies out
beneficial: these usually increase the chances of an organism surviving
what are 3 types of adaptions?
1) behavioral - how organisms acts
2) physiological - processes inside an organism body
3) anatomical - structural features
what is phylogeny?
this is the evolutionary relationship between organisms
the phylogeny reflects the evolutionary branch that led to the organisms
usually shown like a tree diagram, a phylogenic tree
