3.1 2 What is a species?

Question 1

why are species important

Answer 1

measure biodiversity ,help monitor the effect of natural environment changes and changes from human activity

Question 2

morphological species concept

Answer 2

Linnaeus solely on appearnce
outer and inner morphology of organisms
difference and similarities

Question 3

morphological limitations

Answer 3

huge amount of variation in closely related organisms

sexual dimorphism

Question 4

reproductive/biological species concept

Answer 4

group of organisms with similar characteristics that inbreed to produce fertile offspring

Question 5

reproductive limitations

Answer 5

if organisms do not live in the same area are able to breed but because of geography do not-may not interbreed because they are in different areas
genes must be able to combine or flow from parents to offspring
good for most animals however classifying plants interbreed with similar species frequently to produce fertile offspring

Question 6

full reproductive model species definition

Answer 6

a group of organisms with similar characteristics that are all potentially capable of breeding to produce fertile offspring
a group of organisms in which genes can flow between individuals

Question 7

ecological species model

Answer 7

based on ecological niche occupied by the organism.not robust niche def vary species occupy more than one niche

Question 8

Mate-recognition model

Answer 8

based on unique fertiliastion systems including mating behaviour. diffculty as many species will mate with or cross pollinate with other species and may produce fertile offspring

Question 9

Genetic species model

Answer 9

based on DNA evidence people still have to decide how much genetic differnece makes two organisms memembers of different species.

Question 10

Evolutionary species model

Answer 10

based on shared evolutionary relationshisp between species .memeber of a species have shared evolution and are evolving together.there is not always a clear evolutionary pathway fo a particular organism

Question 11

Limitations of species models

Answer 11

1. finding evidence many living species have never been observed mating.breeding programme time consuming,expensive and may prove nothing
2. plants -hybrids
3. many organisms do not reproduce sexually-any defintion concerning reproductive behaviour is irrelevant for bacteria protists and fungi (some)
4. fossils organisms cannot reporduce and may not have accessible DNA but still need to be classified

Question 12

sexual dimorphism

Answer 12

great deal of diffrence between the male and female of a species

Question 13

molecular phylogeny

Answer 13

analysis of genetic material in organisms to establish their evolutionary relationships