Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Classification and Evolution > Flashcards

Classification and Evolution Flashcards

(55 cards)

Start Studying
1
Q

define species

A

group of similar organisms capable of producing fertile and living offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Darwins theory of evolution is based on what observations

A

variation exists between members of the same species
these variations are inherited from parents
organisms tend to overproduce
populations remain stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

from darwins observations, what did he conclude

A

survival is a struggle
those with more advantageous characteristics survive to pass them onto their offspring
over many generations small changes can lead to changes and speciation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the modern theory of evolution is called

A

Neo-Darwinism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

causes of variation in a phenotype

A

environmental and genetic factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the causes of genetic variation

A

mutations- primary source
meiosis
random fertilisation of gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how do mutations cause genetic variation

A

changes to genes and chromosomes may or may not be passed onto next generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

causes of mutations

A

mutagenic agents such as ionising radiation and tobacco smoke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how does meiosis cause genetic variation

A

produces new combination of alleles before they are passed onto the gametes therefore they are all different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does random fertilisation of gametes cause genertic variation

A

produces new combinations of allels and offspring are therefore different to parents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

give examples of continuous variation

A

height, mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

give examples of discontinuous variation

A

blood type, eye colour, hair colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does a normal distribution curve look like

A

a bell shaped curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

environmental influences on genetic variation include:

A

climatic conditions eg temp, rainfall, sunlight
soil conditions
pH
food availability
diet is an environmental impact that can affect height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

individuals genetically predetermined to be the same can height grow to different heights. This typeof variation is produced by?

A

polygenes and the environment

diet can affect height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

continuous variation vs discontinuous variation (4)

A 
continuous: 
shows a full range of intermediate values between 2 extremes 
determined by many genes- polygenic
strong environmental influence 
often a normal distribution curve on a histogram 
discontinuous:
data flows into discrete categories
determined by a flow of genes 
weak environmental influence 
bar chart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define selection pressures

A

environmental factors that limit the population of a species
includespredation, disease, competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

effect of selection pressures

A

determine the frequency of alleles within the gene pool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

define gene pool

A

total number of all the alleles of all the genes of all individuals with a population at a given time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

define fitness

A

the ability of an organism to pass on its alleles to subsequent generations, compared with other individuals of the same species- the fittest individual produces the largest number of organisms that reproduce themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 3 types of adaptions

A

anatomical, physiological and behavioural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

define anatomical adaption

A

a mutation that has caused the physical features of an organism to change eg increased fur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

define physiological adaption

Study These Flashcards
A

a mutation that has changed the biochemistry of that organism eg the ability to oxidise fat instead of carbohydrates

24
Q

define behavioural adaption

Study These Flashcards
A

a learned adaption where the organism has learnt a behaviour that is differnet to their normal routine eg migrating to a diff country in the winter

25
what does MAVAIPS stand for
mutation, allele, variation, advantage/adaption, inheritance, population, speciation
26
three types of natural selection
stabilising selection, directional selection, disruptive selection
27
characteristics of a stabilising selection
def: favours average individuals so preserves characteristics of the population an unchanging environment. the extremes of a phenotype are not favourable and therefore there is a reduction in variation the bell shaped curve gets pushed narrower from both sides
28
characteristics of a directional selection
def: favours one extreme of the phenotype rnage and results in a shif of the mean to the right or left this selection usually follows an environmental change
29
characteristics of a disruptive selection
def; selects against intermediate phenotypes and favours those at the extremes leads to bimodal distribution (2 peaks)
30
disruptive selection leads to overalp between 2 groups of phenotype. how would new species be created
if the 2 groups become unable to interbreed, then each population may give rise to a new species
31
how can new species be formed
when 2 populations of a species are split into diff environments, the reproductive isolation leads to new species
32
outline the evolution of antibiotic resistance
bacteria tolerate levels of antibiotic that would normally inhibit growth
33
describe 2 ways in which antibiotic resistance can become widespread
1- transfer of genetic material between bacteria | 2- increased resistance with each generation due to natural selection
34
how can a population of resistant bacteria develop
if the amount of antibiotic delivered is too low or the course of antibiotics is not completed
35
define classification
organisation of living organsims into groups
36
what does fertile mean
if 2 different species breed,one can have an even number of chromsomes, one can have an odd number of chromsomes therfore the diploid number is odd- this leaves a singular chromosome and therefore offspring is infertile
37
effect of uneven diploid number on meiosis
uneven diploid number means that meiosis cant occure and so fertile offspring are not produced
38
binomial system features
universal system based upon Latina nd greek names the generic names relates to the genus the specific name relates to the species
39
rules of binomial system
names initalics or underlined if handwritten first letter of the generic name is upper case if species name is unknown it can be written as sp
40
do members of the same species have similar genes?
yes- similar or same
41
courtship behaviour helps to achieve the max chance of survival by enabling individuals to:
1-recognise members of their own species 2-identify a mate that is capable of breeding- both need to be sexually mature, fertile 3-synchronise mating- takes place when there is a max probability of sperm and egg meeting 4-become able to breed-by bringing a member of the opposite sex into a physiological state that allows breeding to occur
42
features of phylogenetic classification
based upon the evolutionary relationships between organisms and their ancestors classifies species into groups using hared features derived from their ancestors arranges the groups intoa hierarchy with no overlap
43
what is a taxon
each group within a phylogenetic biological classification
44
what are the names of the taxons
Domain, Phylum, Class, Order, Family, Genus, Species
45
what are the domains in a phylogenetic classification
bacteria, archae and eukarya
46
what are archaea
groups of single celled prokaryotes
47
how do archaea differ from bacteria
their genes and protein synthesis is more similar to eukaryotes membranes contain fatty acid chains and attached to glycerol by ether linkages no murein in their cell walls have a more complex form of RNA polymerase
48
define phylogeny
evolutionary relationship between organisms
49
define hierarchy
large groups split into smaller groups which do not overlap
50
how does a phylogenetic system differ from a simple hierarchy
phylogenetic is based on evolutionary history shows ancestory of groups hierarchal based on shared characteristics
51
limitations of comparing visible characteristics to compare genetic diversity
some visual characteristics are coded for by more than one gene so its difficult to distinguish one change from another some visual characterists may be controlled from the environment and may not have anything to do with a change in the alleles
52
how is comparison of DNA base sequences carried out
DNA extracted from individuals and the nucleotide bases each tagged a diff colour- computer reads the diff colours and shows the order of nucleotides coding DNA is used as these sequences will be very similar within a species
53
ways of comparing genetic diversity
compare the base sequence of DNA compare the base sequence of mRNA compare the sequence of amino acids in proteins
54
explain the principles which biologists use to classisfy organisms into groups
large groups are divided inot smaller groups members of a group have features in common basedon anatomy/ DNA/ homologous structures reflects evolutionary history
55
differences in haemoglobins primary structure can provide evidence of phylogenetic relationships between species. Explain how (5)
mutations change base/nucleotide sequence causes change in AA sequence mutations build up over time more mutations/ differences between distantly related species closely related species have recent common ancestor

Biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions