1
Q
Define the term “classification”.
A
The act of arranging organisms into groups based on their similarities and differences.
2
Q
Define the term “taxonomy”.
A
The study of classification.
3
Q
Define the term “taxonomic group”.
A
The hierarchical groups of classification: domain, kingdom, phylum, class, order, family, genus, species.
4
Q
Define the term “hierarchical”.
A
Arranged so that entity is subordinate to a different to a different entity.
5
Q
Define the terms “phylogeny”.
A
The evolutionary relationships between organisms.
6
Q
List the seven taxonomic groups, in order, from the broadest to the smallest.
A
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
7
Q
Name the taxonomic level that has been added above kingdom.
A
Domain
8
Q
Give 3 reasons why scientists classify organisms.
A
To identify species - by using defined systems of classification the species an organism belongs to can be easily identified.
To predict characteristics - if several members of a group have a specific characteristic it is likely other species in that group will have the same characteristics.
To find evolutionary links - species in the same group probably share characteristics as they have evolved from a common ancestor.
9
Q
Define the term “species”.
A
A group organisms that are able to reproduce and produce fertile off spring.
10
Q
Explain why horses and donkeys are separate species, and why mules are not given a scientific name and are not a separate species.
A
Horses and donkeys cannot produce fertile offspring. Mules are the offspring of donkeys and horses and they are infertile because their cells contain an odd number of chromosomes. Because they are infertile they are not classified as a species, and so are not given a scientific name.
11
Q
Define the term “scientific name”.
A
The taxonomic name of an organism, that consists of the genus and species.
12
Q
Define the terms“binomial nomenclature”.
A
The scientific naming of a species with a latin name made of two parts, the first indicating the genus and the second indicating the species.
13
Q
Define the term “generic name”.
A
The first word that indicates the organism’s genus.
14
Q
Define the term “specific name”.
A
The second word that indicates the organism’s species.
15
Q
State the conventions used in writing scientific names.
A
Written in lower case and in italics or underlined. The first letter of the genus name is capitalized.
16
Q
Name the 5 kingdoms and give examples of the organisms they contain.
A
Prokaryotae -
Bacteria
Protoctista -
algae, protozoa
Fungi -
moulds, yeasts, mushrooms
Plantae -
mosses, ferns,
Animalia -
fish, reptiles, birds
17
Q
Describe the characteristic features of each of the 5 kingdoms: Prokaryotae
A
- unicellular
- no nucleus or any membrane bound organelles
- ring of naked DNA
- small ribosomes
- no visible feeding mechanism
- nutrients are absorbed through cell walls or produced internally by photosynthesis.
18
Q
Describe the characteristic features of each of the 5 kingdoms: Protoctista
A
- mainly unicellular
- contains nucleus and other membrane bound organelles
- some are sessile, but others move by cilia, flagella or amoeboid mechanisms.
- nutrients are acquired by photosynthesis so they are autotrophs, or by ingestion of other organisms meaning they could also be heterotrophs.
- Some could be parasites.
19
Q
Describe the characteristic features of each of the 5 kingdoms: Fungi
A
- unicellular or multicellular
- contains nucleus and other membrane-bound organelles.
- cell wall mainly composed of chitin.
- No chloroplasts or chlorophyll.
- Saprotrophic nutrition (absorbing substances from dead or decaying organisms) .
- no mechanisms for locomotion
- most have a body or mycelium of threads of hyphae
- Some are parasitic
- Most store glucose as a glycogen
20
Q
Describe the characteristic features of each of the 5 kingdoms: Plantae
A
- multicellular
- a nucleus and other membrane bound organelles including chloroplasts
- a cell wall mainly composed of cellulose
- all contain chlorophyll
- most do not move, although gametes of some plants move using cilia or flagella.
- nutrients are acquired by photosynthesis so they are autotrophic feeders.
- store food as starch
21
Q
Describe the characteristic features of each of the 5 kingdoms: Animalia.
A
- multicellular
- nucleus and other membrane organelles but no cell walls
- no chloroplasts
- move with the aid of cilia, flagella or contractile proteins, sometimes in the form of muscular organs.
- nutrients are acquired by ingestion, they are heterotrophic feeders.
22
Q
State the 3 domains of life and the 6 kingdoms that the three-domain system uses.
A
3 domains: Bacteria, Archae, Eukayra,
6 kingdoms: Animalia, Eubacteria, Protoctista, Plantae, Fungi, Archae bacteria.
23
Q
Describe the characteristic features of each of the 3 domains: Eubacteria (bacteria)
A
- 70s ribosomes
- RNA polymerase contains 5 proteins
24
Q
Describe the characteristic features of each of the 3 domains: Archaea
A
- 70s ribosomes
- RNA polymerase of different organisms contains 8-10 proteins
25
Describe the characteristic features of each of the 3 domains: Eukarya
- 80s ribosomes
| - RNA polymerase contains 12 proteins
26
Describe the evidence used to create the “Three Domain System” of classification.
- Scientists can discover evolutionary relationships between organism by comparing DNA and protein structure.
- These observations are used to categorise organisms
27
Define the term “phylogeny”.
The study of living organisms based on their evolutionary relationships.
28
Define the term “phylogenetic tree"
A diagram used to represent evolutionary relationships between organisms. Shows common ancestors.
29
Define the term “sister group”
Two descendants which are split from the same node are called sister groups.
30
Define the term "node"
The nodes on a phylogentic tree are the points where new lines branch off.
31
Define the term “tip” in relation to phylogenetic trees.
Tips represent groups of descendants, often species.
32
Describe the advantages of using phylogenetic trees as a form of classification as opposed to just using taxonomic groupings.
- Uses knowledge of phylogeny in order to confirm that the classification groups are correct, or cause them to be changed.
- Produces a continuous tree, whereas classification requires discreet taxonomical groups, so scientists aren't forced to put organisms into a specific group that they don't quite fit.
- The hierarchical nature classification can be misleading as it implies that different groups within the same rank are equivalent.
33
State 3 different sources of evidence for evolution.
- fossil evidence, paleontology: the study of fossils and the fossil record.
- Comparative anatomy: the study of similarities and differences between organisms' anatomy.
- Comparative biochemistry: similarities and differences between the chemical makeup of organisms.
34
Explain how the fossil record provides evidence for evolution.
- fossils of simpler organisms are found in the oldest rocks whilst fossil of more complex organisms are found in more recent rocks.
- The sequence in which the organisms are found matches their ecological links with each other e.g plant fossils are older than animal fossils because animal life requires plants.
- Study of similarities in the anatomy of fossiled organisms shows how closely related organisms have evolved from the same ancestor.
35
Explain how the relative age of fossils can be determined.
- sediment is deposited on the earth to form layers of rock, different layers correspond to different geological eras.
- Within the different rock layers, the fossils found are quite different. This forms a sequence from oldest to youngest, showing the organisms have gradually changed over time.
36
Explain how comparative anatomy provides evidence for evolution.
- Homologous structure is a structure that appears superficially different in different organisms but has the same underlying structure
- The presence of homologous structures provides evidence for divergent evolution, which describes how from a common ancestor different species have evolved.
37
Define the terms “homologous structure” and “divergent evolution”.
Homologous structure - a structure which appears superficially different but has the same underlying structure.
Divergent evolution - species diverge over time into two different species resulting in a new species becoming less like the original one.
38
Explain how comparative biochemistry provides evidence for evolution.
- Gather molecular evidence involves analysing the similarities in proteins and DNA.
- More closely related organisms will have more similar molecules.
- You can compare things like how DNA is stored and the sequence of DNA bases.
- From this comparison, scientists can identify the point at which two organisms last shared a common ancestor.
39
Summarise how Darwin and Wallace formulated the theory of evolution by natural selection.
He noticed that different islands had different finches with different beaks, and so he realised that the design of the beaks was linked to the food available.
Those birds with the more well-suited beaks, survived to reproduce and pass on their genetic information.
40
Define the term “variation".
The differences in characteristics between organisms.
41
Define the term “interspecific variation”.
The differences between organisms of different species.
42
Define the term “intraspecific variation”.
The differences between organisms of the same species.
43
Name and describe the two causes of variation.
- An organism's genetic material:
The differences in the genetic material an organism inherits from its parents leads to genetic variation.
- The Environment:
The environment in which the organisms lives causes environmental differences.
44
Describe 5 causes of genetic variation between individuals within a population.
- Alleles:
with a gene for a particular characteristic, different alleles produce different effects and different individuals within a species population may inherit different alleles of a gene.
- Mutation:
Changes to the DNA sequence and therefore to genes can lead to changes in the proteins that are coded for.
- Meiosis:
Gametes are produced by meiosis. Each gamete receives half the genetic content of a parent cell and the genetic material is mixed up by independent assortment and crossing over.
- Sexual reproduction:
Offspring produced from two individuals inherits genes from each parent.
- Chance:
Different gametes are produced and in reproduction, it is chance as to which two combine. This is why individuals differ from siblings.
45
State 3 characteristics that are solely genetically-determined.
- Eye colour
- Blood group
- Shape of the earlobes
46
3 solely environmentally-determined characteristics.
- Scars
| - Piercings
47
3 characteristics that are clearly a combination of genetics and the environment.
- Weight/ height
- Hair colour
- Skin colour
48
Define the terms “continuous variation”.
A characteristic that can take any value within a range.
| Most continuous variations are controlled by multiple genes.
49
Define the terms “discontinuous variation”.
A characteristic that can only result in discreet values e.g blood type. Most discontinuous variations are controlled by a single gene.
50
Describe the causes of variation that result in discontinuous variation.
Variation determined purely by genetic factors falls into the discontinuous category.
51
Define the term “polygenic”.
A characteristic that is controlled by a group of genes.
52
Define “multifactorial”.
Characteristics which are dependant on a number of factors, genetic or environmental.
53
Describe the causes of variation that result in continuous variation.
Characteristics that show continuous variation are not controlled by a single gene but a number of genes, polygenes, and are often influenced by environmental factors.
54
State the types of graph used to represent continuous and discontinuous variation within a population.
Continous:
Frequency tables which are then plotted into a histogram. A curve is normally drawn to show a trend.
Discontinuous:
Bar chart or pie chart
55
How to draw a histogram.
X axis: Class width
Y axis: Frequency density.
Frequency density = frequency/ class width
56
Define the term “normal distribution curve” and give 4 characteristics of a normal distribution.
A bell-shaped curve with the peak at the mean:
- Mean, median and mode are the same
- curve is symmetrical around the mean
- 50% of data points are less than the mean and 50% are greater than the mean.
- Most values lie close to the mean.
57
Define the term standard deviation.
How spread out the data is - the greater the deviation the greater the spread of data.
58
Describe the meaning of each of the symbols in the equation for calculating standard deviation.
Look it up and name the symbols.
59
Explain why statistical tests are important and what they are used for.
Statistical tests can be used by scientists to determine the significance of data collected.
60
Define the terms “hypothesis” and “null hypothesis”.
Hypothesis - an idea or an explanation which then needs to be confirmed through experimentation.
Null hypothesis - the proposition that your results show no significant difference between populations. The results are the product of chance variation in the sample.
61
Explain what a “test statistic”, a “critical value” and a “p-value” are, and show how they are related.
Test statistic - a standardised value that is calculated from the sample.
Critical value - a point on the scale beyond which you reject the null hypothesis.
P-value - the probability of finding the results which mean the null hypothesis is true.
62
Describe when a “Student’s t-test” would be used to analyse data.
Used to compare the means of data values of two populations. The data must be normally distributed and enough data must be collected to calculate a reliable mean.
63
Describe when a “Spearman’s rank correlation” would be used to analyse data.
This is used to consider the relationship between two sets of data. Used to see if there's a correlation.
64
Describe when a paired t-test would be used and when an unpaired t-test would be used to analyse data.
A paired t-test: to analyse the difference between the means of two data sets where the data from both data sets was collected from the same subject.
Unpaired: when the data from both data sets was collected from different subjects.
65
Describe the meaning of each of the symbols in the equation for calculating the t-value (the test statistic) from an unpaired Student’s t-test.
Look it up and do it.
66
Describe the meaning of each of the symbols in the equation for calculating the correlation coefficient (test statistic) from a Spearman’s rank correlation.
Look it up and do it.
67
Define the term “adaptation” and state the 3 types of adaptation.
Adaptations:
Characterisitcs that an increase an organism's chance of survival and reproduction in an environment.
The types;
- Anatomical (physical features)
- behavioural (can be inherited or learnt from parents)
- Physiological (processes that take place inside an organism)
68
Give 4 examples of anatomical adaptations.
- body covering (e.g scales, hair, feathers which might help to fly or stay warm)
- Camouflage (outer colour which allows an organism to blend into its environment, less vulnerable)
- Teeth (shape and type are related to an animal's diet)
- Mimmickry (copying another animals appearance or sounds, allows harmless animals to fool predators into thinking they are dangerous)
69
Give 3 examples of behavioural adaptations.
- Survival behaviours (a possum plays dead, and rabbits freeze)
- Courtship (display elaborate behaviours to attract a mate which increases chance of reproducing)
- Seasonal behaviours (migration and hibernation, allows animals to cope with environmental changes)
70
Given 3 examples of physiological adaptations.
- Poison production (reptiles and plants produce poisons to protect themselves from being eaten)
- Antibiotic production (Some bacteria produce antibiotics to kill other species of bacteria in the surrounding area)
- Water holding (storing water in the body to allow it to survive in dry climates)
71
Define the term “analogous structure”.
Structures that have adapted to perform the same function but have a different genetic origin.
72
Define the term“convergent evolution”.
Organisms evolve to have similarities because the organisms adapt to similar environments or other selection pressures.
73
Compare the features of the marsupial mammals and the placental mammals.
Marsupial mammals:
- start life in the uterus but then leave and enter the marsupium (which is a pouch) while they are still embryos.
- e.g mole skin colour is white to orange.
Placental mammals:
- connects the embryo to its mother's circulatory system so that it reaches a high level of maturity before birth.
- e.g mole skin colour is grey to match their surroundings.
74
Define the term “evolution”.
The change in allele frequency within a gene pool over time.
75
Define the term "natural selection".
The process by which organisms best-suited to their environment survive and reproduce passing on their characteristics to their offspring, through their genes.
76
Define the terms “allele frequency”.
The relative frequency of a particular allele in the population at a given time.
77
Define the term “gene pool”.
The sum total of all the genes in a population at a given time.
78
Define the term “selection pressure”.
Factors that affect an organism's chance of survival or reproduction.
79
Define the term “selectively neutral allele”.
A variety of a gene that doesn't provide a selective advantage or disadvantage to the organism.
80
Define the term “advantageous allele"
A variety of a gene that provides a selective advantage to the organism.
81
Define the term “advantageous characteristic"
One form of a part of organism's phenotype which provides it with a selective advantage.
82
Describe the steps in the process of adaptations evolving by natural selection.
- Organisms within a species show variation in their characteristics which are caused by genetic variation.
- Organisms whose characteristics are best adapted to a selection pressure (e.g predation or competition) have an increased chance of surviving and successfully reproducing.
- Successful organisms pass the allele encoding the advantageous characteristics onto their offspring.
- This is repeated for every generation over time the proportion of individuals with the advantageous adaptation increases.
- Therefore the frequency of the allele that codes for this increases in the population gene pool.
- Over very long periods of time, this process can lead to the evolution of new species.
83
Describe how human activity has resulted in evolution in populations of the bacterium Staphylococcus aureus, the Sheep blowfly Lucilia cuprina, and the bacterium Flavobacterium.
- Sheep blowflys laid eggs in sheeps' tails, pesticides were introduced and they became resistant to them.
- Flavo bacteria, a strain of bacteria which have evolved to digest nylon and live in waste water from factories that produce nylon.
- Staphylococcus aureus has developed resistance to many antibiotics, when exposed resistant individual survived... natural selection.
84
Explain how natural selection has resulted in the change in frequency of dark and pale moths in populations of the peppered moth (Biston bettularia) near industrial towns and cities over time.
- In the industrial revolution trees became darker and so the dark moths were better adapted so more survived etc
- So that frequency of the dark allele increased. Now trees are lighter the frequency of the pale allele in the moth gene pool increased.
Biology
flashcards
Decks in class (35)
# Cards
-
The Biological Importance of Water34
-
Microscopy41
-
Carbohydrates33
-
Cell Structure46
-
Lipids28
-
Proteins36
-
Membranes Structure and Function25
-
Transport across membranes56
-
Enzymes68
-
Nucleotides and Nucleic acids34
-
DNA replication and protein synthesis34
-
Specialised cells and stem cells42
-
Exchange surfaces - Mammalian gas exchange.45
-
Exchange surfaces - Insect and fish gas exchange.24
-
Transport in Animals23
-
Classification and Evolution84
-
Biodiversity71
-
Photosynthesis51
-
Ecosystems88
-
Sustainability69
-
Populations18
-
Respiration56
-
Communication and Homeostasis45
-
Hormonal Communication54
-
Excretion and Liver17
-
Excretion and Kidney41
-
Kidney failure and Medical diagnosis29
-
Cellular Control59
-
Genome Manipulation67
-
Genome Manipulation Ethics0
-
Neuronal Communication72
-
Animal Responses63
-
Animal Responses - Muscle.26
-
Patterns of Inheritance80
-
Plant Responses27
