variation Flashcards
what is variation
differences that exist between individuals
what are the two types of variation
1 instaspecific- variation within a species
2 interspecific- variation between different species
Variation can be _____ or ______
continuous - variation within a range but not any distinct categories
discontinuous- variation with two or more distinct categories each individual falls into only one there’s no intermediate
Variations can be caused by two things
genetic factors or genetic factors or both…
how does genetic factors influence variation
- individuals in same species have same genes but diff alleles
- genes and alleles make up its genotype
- differences in genotype result in variation in phenotype
- you inherit genes so the genetic facors are inherited
how do environmental factors influence variation
variation occurs at different environments, climate food and lifestyle
environmental characteristics can change over the period of an organisms life eg. accents
in some cases both environmental and genetic factors cause variation
genetic factors determine the characteristics an organisms born with but environmental factors can influence how some characteristics develop
eg. height - genes determine how tall an organisms can grow but nutrition availability affect how tall it actually grows
flagellum- genes determine if if a microorganism can grow but it might only grow in certain environments
what would a normal distribution with a symmetrical bell curve look like with a large vs small standard variation
draw
what does standard deviation measure
tells you how much the values in the sample vary. the spread either side of the mean
recite the standard deviation formula
/—————————-
s=\/sum of (x- mean x)^2
—————————-
n-1
what are the three types of adaptations
behavioural physiological anatomical
adaptations develop due to
evolution by natural selection
define adaptations
means an organism has features that increase its chances of survival and reproduction and also chances of its offspring reproducing successfully
behavioral adaptations
the way an organism acts that increases its chances of survival
physiological adaptations
processes inside an organisms body that increase its chance of survival
anatomical (structural) adaptations
structural features of an organisms body that increase its chance of survival
organisms from different taxonomic groups may have similar features even though they’re not closely related
this is because they have evolved in similar environments and to fill similar ecological niches (en is the role of an organism in its habitat where it eats what it eats when)
Convergent evolution:
when two species evolve similar characteristics independently of one another
marsupial mole and placental mole look alike but aren’t closely related
very similar anatomical features because of evolving in similar environments however evolved independently on different continents
both live in underground tunnels and burrow for food supply their adaptations include
small or no eyes
no ears - streamline
powerful paws for digging
claws for digging
tube shaped body with come head
