Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology > module 3 > Flashcards

module 3 Flashcards

(58 cards)

Start Studying
1
Q

Define the term selection pressure

A

external agent which affects an organism’s ability to survive in a given enivronnment

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

Define the terms ecosystem, community, population

A

ecosystem: all of the organisms in a rea plus the nonliving parts of their environment

population: group of the same species living in the same are

community: group of different species living in the same area

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

List a range of biotic factors

A

competition, predation, pathogens, plants, animals

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

List a range of abiotic factors

A

temperature, availability of water, salinity, availability of light, nutrients,

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

Compare the structural, behavioral and physiological adaptations that have allowed cane toad populations to rise rapidly

A

structural:
- tough warty skin which serves as a defence against predators

behavioural:
- nocturnal activity patterns to avoid day time predators and to search for food more effectively at night

physiological:
- secrete a certain kind of fluid called bufotoxin which can be fatal to other animals

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

Describe the selective pressures that cane toads impose on other organisms

A
  • predation pressure
  • competition for resources
  • toxicity as a defence mechanism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define the term adaptation

A

Adaptations are features that improve the chances of survival of an organism in its specific environment

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

what is biodiversity

A

Variety of all living species of organisms

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

types of bio diversity

A

Ecosystem diversity → variety of ecosystems in a given place
Ecosystem: community of living things and physical environments as well as the interactions between them

Species diversity → variety of different living species in an area

Genetic diversity → variation of genes within a species
- Provides the variation necessary for natural selection to occur → low species diversity means they are more at risk

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

Species

A

interbreeding population that produces fertile offspring young (if given a chance they will not interbreed with other populations

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

Mass extinction events

A

selection pressures
- Asteroids → decrease
Rapid changes in climate
-Cambrian explosion → increase because more oxygen in the atmosphere
Anthropocene extinction → anthropogenic (environmental change caused or influenced by people, either directly or indirectly)

human induced:
- climate change
- introduction of new species (eg. predators such as foxes),
- population growth
- introduction of diseases

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

j

A

j

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

Modern evolution theory

A

all organisms descended from a single common ancestor –> charles darwin –> galapagos finches

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

Galapagos finches

A

Birds on different islands in the Galapagos had different beak shape
that were suited for the type of food on each island
- Larger beaks → nuts
- Smaller → insects
- All derived from the same common ancestor
- Divergent evolution → several distinct species from a common ancestor → adaptive radiation
- Each new species adapted to fill an ecological niche eg. eating a specific food source

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

ecological niche

A

the role an organism plays in an ecosystem

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

what is a mechanism for evolution

A

the process of natural selection –> driven by mtation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Speciation

A

species arose from a single form of life

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

Darwinian theory of evolution by natural selection:

A

evolution occurs as a function of ‘survival of the fittest’ (the continued existence of organisms which are best adapted to their environment) but requires that the ‘fittest’ offspring are also able to pass on their genetic information that determines their more suitable traits

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

what does natural selection state

A
  1. Natural variation exists in a population due to sexual reproduction and mutation
  2. More offspring are produced that can survive in a population → if population remains to be constant the offspring must die
  3. Struggle for existence → individuals with traits suited better for the environment will survive → have the opportunity to pass on their genes and reproduce
  4. Over long periods of time the favourable traits of individuals will become prevalent in the population
  5. As new adaptations accumulate → population will become different → speciation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Process of evolution

A

variation, selection pressure, death

variation, selection pressure, survival from those with favourable characteristics, reproduction, passing on favourable characteristics to offsprings, dominance, majority of the population has the favourable characteristics

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

how do camels show adapttaion

A
  • Long, shaggy fur that keeps them warm but which they can shed during hot months
  • Wide hooves keep them from sinking in sand
  • Energy-rich fat stored in their humps enables them to survive long periods without food.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

law of superposition

A

Within a sequence of layers of sedimentary rock, the oldest layer is at the base and that the layers are progressively younger with ascending order in the sequence
- Shows a change from simple organisms in the oldest rocks to complex organisms in the youngest rocks

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

Fossils

A

preserved remains of traces of animals, plants and other organisms from the remote past which allows us to trace the evolution of species overtime

process
- Organism dies
- Layers of sediment accumulate on the top of the dead organism
- The hard parts of the organisms become impregnated with minerals
- Uplift and erosion expose the fossil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Conditions required for fossil formation:

Study These Flashcards
A

Quick burial → prevents decomposition
Minimum disturbance
Possession of hard parts → less likely to decompose and decay (eg. bones and teeth instead of tissue)
Eventual exposure → so the specimen can be found

25
types of fossils
body and trace
26
radioisotope datings
Found in rocks and decay into new (daughter) isotopes that are more stable - Numerical (age) [absolute] → specific number of years - Determined through the extent of decay of radioactive isotopes - Counting the number of new (daughter) isotopes → ratio between the number of radioactive parent elements and the amount of stable daughter elements Suing the known decay rate to calculator the length of time required to produce a specific number of new isotopes Relative age --> position
27
Transitional fossils
Fossils which have characteristics of two different groups of organisms Whales - small poorly formed hind leg and teeth → consistent with land carnivores - Vestigial pelvis and pentadactyl pelvis → consistent with land based vertebrates Archaeopteryx → first real example of a transitional fossil - Reptiles - Toothed beak, wing claw, long tail with many vertebrae - Birds - Airfoil wing with contour feathers
28
Biogeography
Study of past and present geographic patterns of species distribution and ecosystems and the processes that result in such patterns - Modern distribution of plants and animals supports the theory of continental drift - evidence - galopogas finches ratite birds --> cant fly
29
Mutation
A change in the DNA sequence of an organism
30
Codon
three-letter genetic sequence found in both DNA and RNA. It codes for a specific amino acid, or start and stop signals, for the protein synthesis process
31
Comparing amino acid sequences
Allows you to see the level of similarity between two species - Molecular clocks constructed to infer when divergence between two species occurred - Measures the number of changes, or mutations, which accumulate in the gene sequences of different species over time - Amount of evolutionary change to occur Molecular evidence for evolution includes that all living things share the same biochemical building blocks
32
Comparative embryology
- Similarities during embryonic growth highlights that these animals have evolved divergently from a common ancestor - Embryos of different organisms can be compared as further evidence of evolution
33
Comparative anatomy
Evolutionary development of species came from examining anatomical similarities between organisms - homologous and analogous
34
homologous
structures, body features that are similar in two different species because they were inherited from a common ancestor Vertebrate skeletons --Vertebrate pentadactyl limb
35
Analogous structures
These similarities in unrelated species They are not inherited from a common ancestor - Dolphins have fins and tails. Sharks also have fins and tails
36
Vestigial structures
no function within the current species --> Often a leftover from ancestral species → no disadvantage → not selected out by natural selection Snakes → pelvis and limb bone Whales → pelvis Fish and salamanders → eyes (they are blind) Humans → appendix, wisdom teeth, tail vertebrae
37
Biochemistry
The more closely related organisms are → the more similar their biochemical makeup is → more likely to have evolved from the other Evidence of a common ancestor is seen from the universality of DNA as genetic material Similarities: All organisms use RNA or DNA → organisms evolved from a single species that used RNA or DNA All eukaryotes have a similar structure to their chromosomes All photosynthetic organisms use chlorophyll All eukaryotes use cytochrome C → respiratory enzyme Most organisms use haemoglobin (protein used to transport oxygen) Difference in genes is due to evolution selecting for certain traits
38
Cladograms
show how organisms are classified based on their evolutionary relationships
39
Modern examples of evolution
-Antibiotic resistance in bacteria -DDT resistance in mosquitoes
40
DDT resistance in mosquitoes
Natural selection → in a population there is genetic variation → some mosquitoes are resistant → use of DDT will kill susceptible mosquitoes leaving the resistant ones → they will survive and reproduce →over time population will become resistant to DDT
41
Antibiotic resistance in bacteria
1. In a population of bacteria, variation exists due to mutations → some are resistant to antibiotics while others are not 2. Antibiotics are added → acting as selection pressures 3. Bacteria with gene for antibiotic resistance will survive, reproduce (via binary fission: asexual reproduction by a separation of the body into two new bodies) and pass on this trait to offspring → trait of resistance is the favourable trait in the environment 4. Over time → new resistant strain of bacteria will develop
42
How is gene resistance passed on
Vertical gene transfer Bacteria reproduces very quickly → develop mutations in short spans of time → the mutation that survives passes on the mutation → the whole population becomes resistant Horizontal gene transfer Passes on to a different species of bacteria → not its offspring
43
order
prokaryotes eukaryotes jawless fish reptiles non-vascular plants terrestrial organisms dinosaurs mammals angiosperms
44
Causes of evolution:
- Genetic drift: The change in frequency of an existing gene variant in the population due to random chance Blue eyes and brown eyes get married but all offspring might have brown eyes → blue eyes are eliminated by chance - Gene flow: Introduction of genetic material (by interbreeding) from one population of a species to another Changes the composition of the gene pool → sum of a population’s genetic material at a given time A bee carrying pollen from one flower population - Bottleneck effect: The size of a population is severely reduced Caused from major events such as natural disasters - Founder effect: When a small group of individuals breaks off from a larger population to establish a colony
45
Microevolution
Happens on a small time scale → one generation to the next within a population Change in frequency of a gene population Four types - Mutation - Migration - genetic drift - natural selection
46
Macroevolution
Major evolutionary change, patterns and processes → above the species level → beyond intraspecific Horse → selection pressure of predators and food Modern horses run on a single toe → allows them to outrun predators Fossil records show that ancestors had many toes → pentadactyl limb Evolved large flat molar → allows them to break down the tough grass that has become abundant
46
Punctuated equilibrium
- little to no change in organisms as there are little to no new selection pressures - In times of sudden environmental stability (floods etc.) → change occurs more rapidly amongst populations especially if they are small in size
47
Gradualism
increases gradually at a very steady, slow rate
48
Adaptations
features that improve the chances of survival of an organism in its specific environment - Structural - Behavioural - Physiological
49
structural
anatomical and morphological features that allow a species to survive in the environment where it lives
50
Behavioural
actions and behaviours of an organism acts to increase its chances of survival
51
Physiological
modifications of internal functions that assist the organism survival in its environment and its metabolism
52
Animal adaptations
Structural adaptations - Fur and feathers → insulate for hot and cold weather - Feathers and fur can reflect or absorb solar radiation (darker more lighter less) Behavioural adaptations - Nocturnal and diurnal → forage in milder conditions and avoid heat loss - Burrows → keeps away from extreme conditions on the surface Physiological adaptations - Changes in metabolism or production of different chemicals (eg. sweat/venom) - metabolic activity Hibernation → inactive state resembling deep sleep to help survive cold climates (behavioural as well)
53
Plant adaptations
Structural adaptations - Thick waxy cuticle to reflect the suns heat and reduce water loss - Eucalyptus leaf hang vertically Behavioural adaptations - Respond to the environment through their growth and movement - Detect sunlight Sun changes direction the plant will change direction (phototropism) Physiological adaptations - Close stomata during low humidity high temperatures Open during the morning, late afternoons, night
54
Divergent evolution
process where two or more populations of a species become less similar (diverge) Sympatric speciation - Ancestral species evolve into two separate species within the same physical or geographical location → slight behavioural modifications Allopatric speciation - Ancestral species become physically or geographically separated → they evolve independently which leads to separate species Earthquake, volcano, climate change
55
Convergent evolution:
process by which unrelated (or distantly related) organisms evolve to become more similar (eg. body form, colour, behaviour, organs) - Wings in bats, insects birds Due to similar selection pressures and ecological niches → wings have independently rise
55
Coevolution
when two or more species reciprocally affect each other's evolution through the process of natural selection eg bees and flowers
56
Cane Toads
- Deliberately introduced from Hawaii to control the population of scarab beetles that are infesting sugarcane crops - Beetles were on the top of the plant that the cane toads could not reach Tough and adaptable species → poisonous, few predators Expanded their range rapidly → slow toads were at the back of the invasion front whereas the fast toads (bigger and longer legs) were at the front Selection pressure driving the movement of the toads → colonising new areas so they don't have to compete for food, bodies of water, mates In order to control the population → physical traps Toxin to lure the tadpoles

biology (11 decks)

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