Biology 2 Flashcards
Mutation what is it?
A permanent change in DNA
Types of mutation
Insertion
Substitution
Deletion
Substitution
Hunting tons disease
Insertion
Sickle cell anaemia
Deletion
Digeorge syndrome
Independent assortment
During meiosis pairs of chromosomes can line up in different ways at equator
Crossing over
A section of one chromosome crosses over another chromosome then breaks and rejoins = different recombination of features in gametes
Genetic variation causes
Mutation
Independent assortment
Crossing over
adaptation
species evolves characteristics which enable it to survive and reproduce in a particular habit
3 types of adaptation
structural
behavioural
functional
structural
physical structure change
structural example
fish - fins (gills to breathe)
behavioural example
nocturnal
hibernation
functional example
camoflauging
kangaroo pausing pregnancy
biodiversity
number of different species present in a particular area and genetic diversity of genes
evolution
creation of biodiversity
variation
diversity within a species
two types of variation
genetic and environmental
5 steps of natural selection
Variation Environment Selection Survival Reproduction
isolation
separation in environment results in reproduction of two species
what happens during isolation
mutation and natural selection
types of isolation
geographical
temporal
behavioural
geographical isolation
two pop of same species seperate due to sine typeof physical barrier
geographical isolation example
oceans
rivers
mountain ranges
temporal isolation
different types of season coming out at different times
example of temporal isolation
toad species come out in summer and winter
behavioural isolation
mating ritual differs
evidence of evolution
fossils
comparative anatomy
dna and protein structure
embryology
fossils
preserved evidence of a previously living organism
conditions of fossilisation
rapid burial
lack of oxygen
stagnant swamps
types of fossils
original fossils
replacement fossils
indirect fossils
indirect fossils
not parts of organisms but traces of it
moulds
imprint showing outside of organism
cast
organism covered by mud
best types of environment for preserving organism
amber
permafrost
peat
amber
solid plant sap or gum
permafrost
frozen land
peat
decomposed plants like moss
what type of rock are fossils found in
sedimentary
what are index fossils used for
used to identify geological periods
index fossil characteristics
abundant
large geographical range
highly distinctive
short time
stratigraphy
comparing layers
transitional fossils
fossils of organisms that show features of 2 different groups
tetrapods
animals with four legs
homologous tetrapod limbs
one long bone attached to two other long bones
4 bones in tetrapod
ulna
radius
humerus
cmp
homology
similar structures from a common ancestor
pentadactyl limbs
same base with 5 digits
comparative embryology
early embryos of all vertebrates same structure
embryology characteristics
notochord (spinal cord) gill slits (neck)
comparitive dna
heat up DNA which seperate into 2 different strands
two strands hybridise i
what are proteins made of
amino acids
number of cysosome c in different species derernubes
how close human dna is to other animals
4 observations of Charles Darwin
Produce more than can survive
Variations are passed on and inherited
Show variation in characteristics
Population is constant
