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BIOLOGY TOPIC 5 EVOLUTION - Leaderboard
BIOLOGY TOPIC 5 EVOLUTION - Details
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70 questions
| 🇬🇧 | 🇬🇧 |
| What provides evidence for evolution? | The fossil record |
| What does evolution mean? (2) | Cumulative change in the heritable characteristics of a population over time = encoded by genes and transferred as alleles a change in the allele frequency of a population's gene pool over successive generations |
| How would you describe the variation within a population? | Continuous and follows a normal distribution bec it is gradual + cumlative |
| When does evolution occur? | When heritable characteristics of a species changes |
| What does adaptive radiation mean? | Its shows how the evolution of homologous structures can be similar in structure but have different functions in different animals |
| How does evolution occur? | Variation: genetic mutations chromosomal abnormalities sexual reproduction gene flow (migration) selective pressures: random events (Genetic drift) directional forces (natural or artificial) |
| What is a mutation? | Change in the nucleotide sequence in the genes eg: germline mutations in gametes (Sex cells) can be passed to offspring |
| What shows that artificial selection can cause evolution? | Selective breeding of domesticated animals |
| What are the 3 ways in which meiosis causes variation? | Crossing over = DNA segments are exchanged between homologous pairs Independent assortment = random separation of homologous pairs Random Fertilisation = random fusion of 2 haploid gamers |
| What is gene flow? | The movement of alleles between different populations |
| How do populations within a species evolve? | They can slowly change into separate species through evolution eg: continuous variation across the geographical range of related populations |
| How does different geographical locations cause variation within a species? (5) | They experience different ecological conditions adapt to these conditions differently = gradually diverge degree of divergence depends on how separated they are and how long they have spent apart farther and longer time apart = more divergence |
| How does gene flow cause variation? | It changes the diversity of a population by immigration or emigration = introduces genes from an alternative population |
| What are population bottlenecks? how do they affect genetic drift? (3) | Drastically reduces the size of a population eg: environmental disaster, hunting to a point of extinction, habitat destruction = enhances genetic drift |
| How would you describe the variation within a population? | Continuous and follows a normal distribution bec it is gradual + cumlative |
| What is the founder effect? how do they affect genetic drift? (3) | A loss of genetic variation when a new population is formed from a small number of individuals form the larger population |
| How does natural selection change a gene pool? | Changes the composition of a gene pool because of different selective environmental pressures eg: a lizard only eating green beetles = more brown beetles |
| What is speciation? | When populations of a species can't interbreed and produce offspring |
| What to the evidence for evolution include? (4) fhsg | Fossil record homologous structures selective breeding geographical distribution of organisms |
| How does artificial selection cause change in the gene pool? | Involves selective breeding or DNA manipulation to create more favorable traits in their offspring |
| How does speciation occur? | Mechanisms of change = reduces variation and increase genetic divergence between geographically isolated populations = speciation |
| What are fossils? fossil record? | Preserved remains or traces of organisms all the fossils (discovers and undiscovered) is the fossil record |
| What is the limitation to using a fossil record? | Fossilization needs a rare set of circumstances = gaps in the record |
| What are the 3 sources of variation? | Genetic mutations gene flow sexual reproduction |
| What are the 3 mechanisms for change? | Genetic drift natural selection artificial selection |
| How can evidence for evolution be shown? | Identifying similarities in unrelated organisms = common ancestor showing a change in characteristics between current and ancestral species |
| How are fossils dated and put in order for the law of fossil succession? | It is determined by which rock layer the fossils found in (strata) pros before euks inverts before verts |
| What are transitional fossils? | Shows the forms in between which happened to show a connections between species it demonstrates common traits in the ancestor and descendants eg: archaeopteryx (links dinosaurs to birds) |
| How does genetic drift affect gene pool? | Change in the composition of a gene pool bec of chance events has a greater affect when the population is small |
| What is the law of fossil succession? | Shows a systematic order for when different species appeared eg: ferns appear before flowers |
| What are homologous structures? | A structure that different species has but is used in different ways they show divergent evolution by adaptive radiation = show common ancestry more similar = closely related eg: pentadactyl limb in vertebrates (5 digit limbs) |
| Which species can the pentadactyl limb be seen in ? | Man, horse, whale, turtle, frog, bird |
| What is adaptive radiation? | Rapid evolutionary diversification when members of a species live in niches with different conditions = they adapt in response to the selective pressures eg: different beak shapes in darwin's finches |
| What is selective breeding? | Form of artificial selection where humans breed animals with desirable characteristics to increase the frequency of these traits eg: race horses are bred for speed eg: beagles are bred for hunting |
| What is an example of evolution? (moths) | Peppered moths had 2 forms white and black in an unpolluted environments the trees has pale lichen = camo for the lighter moth in a polluted environment the soot blackened the bark and killed the lichen = camo for the dark moth = after the industrial revolution the population of white moths decreased |
| What are the requirements for fossilisation? | Preservation of bones exposed to high pressure (Rapid burial) = mineralisation anoxic conditions (low oxygen) = stops decomposition |
| What are vestigial structures? | Reduced remains of functional organs in ancestors eg: whales have a vestigial pelvic bone |
| What is the condition for natural selection to occur? | There needs to be variation among members of the same species |
| What are processes that cause natural selection? ICEAGE | Inherited variation: within a population Competition: overproduction Environmental Pressures: cause selection Adaptations: individuals with beneficial traits are more likely to survive Genotype Frequency: changes over time Evolution: change in allele frequency within the population |
| What causes variation between individuals in a species? (3) | Mutation meiosis sexual reproduction |
| How do mutations cause variation? (3) | Changes the nucleotide sequence in a section of DNA = new alleles are formed can be beneficial, detrimental or neutral |
| What are the 3 types of mutations? | Beneficial: (missense) change gene sequence and creates new variations detrimental: (nonsense) overrule normal function of the trait neutral: (silent) no effect |
| What are adaptations? | Characteristics that make an individual more suited to its environment |
| How does crossing over in meiosis cause variation? | DNA segments are exchanged bw homologous chromos in P1 = all 4 recombinant chromatids will be genetically different offspring would have a unique gene combination not present in either parent |
| How does independent assortment cause variation? | In M1 the chromosomes direction towards the opposite pole is random = diff combos of chromosomes can be inherited |
| How does sexual reproduction cause variation? | Fusion of 2 different haploid gametes = diploid zygote = divides by mitosis to form an embryo |
| What happens when species produce more offspring than the environment can handle? (4) | With plenty of resources population grows to its biotic potential (J curve) as population grows = environmental resistance sets in bec resources become limited (plateaus) overproduction = competition and struggle for survival growth doesn;t exceed the carrying capacity (k) |
| What are some examples of environmental pressures? PANDA PAW | Predators Available resources Nutrient supply Diseases Accumulation of wastes Phenomena (disasters) Abiotic factors Weather |
| How does natural selection occur with adaptation? | The better adapted individuals survive and produce more offspring while the less adapted die / make fewer offspring |
| What are different types of adaptations? | Structural: physical differences (neck length) Behavioral: difference in activity (possums pretending to die) Physiological: in response by vital organs (homeothermy) Developmental: changes across a lifespan (senescence) |
| How does allele frequency change? | Better adapted individuals survive and pass on their genes = change in allele frequency in the population bec some genotypes will be more common = evolution |
| What is adaptive radiation?(3) | Rapid evolutionary diversification of a single ancestral line when a single species live in different niches with diff environmental conditions each member develop different characteristics in accordance to their selective pressures |
| How is adaptive radiation seen in Darwin's finches? (3) | They have different beak shapes based on their type of nutrition in 1977 a drought increased the f of larger beak sizes through natural selection dry conditions = plants making seeds with tougher seed casings |
| What are antibiotics? | Chemicals made by microbes to kill or inhibit the growth of bacteria = used for infections some bacterial strains have evolved antibiotic resistance genes and reproduce through binary fission selective pressure of antibiotics = antibiotic resistance gene to be more frequent (Evolution) |
| Why is natural selection important? | Increases F of useful characteristics so that the individual is better adapted and reduces the characteristics that cause changes within a species |
| What is an example of antibiotic resistance? | Golden staph causes infections to the skin (lesions) treated with methicillin but bacterial strains developed resistant (MRSA) Alternative antibiotics are prescribed now |
| Who proposed the theory of natural selection? what did they say? | Charles Darwin and Alfred Wallace the ones most responsive to change survive |
| What causes inheritable variation among members? (3) | Mutations = germline mutations (gametes) cause changed characteristics in offspring meiosis = crossing over + random assortment cause gamete variation sexual reproduction = fusion of 2 diff gametes make a genetically distinct zygote |
| What is the binomial system? | A system of naming organisms and is universal among biologists when new species are discovered |
| What are the 3 domains of life? | Eukarya = eukaryotic organisms (membrane bound nucleus) archaea = extremophilic prokaryotic organisms (lack nucleus) eubacteria= common prokaryotic organisms (lack nucleus) |
| What is the hierarchy of taxa? Katy Perry Came Over For Grape Soda | Kingdom Phyla Class Order Family Genus Species |
| Why are groups of species sometimes reclassified? | When new evidence shows that previous taxon contains species that have evolved from diff ancestral species |
| What are the uses for classification? (4) | To collect and sort info about different organisms to identify organisms according to a global system to compare organisms based on common features Demonstrate evolutionary links |
| What is artificial classification? (4) | Groups organisms based on non-predictive features easy to develop stable but it doesn't consider how species are related so its not used much |
| What is natural classification? | Groups organisms according to evolutionary relationships predictive but highly changeable |
| What is phylogenetic classification? | Differentiated organisms based on genetic features |
| What are the 3 types of classification? | Artificial natural phylogenetic |
| What is included in natural classification? | The genus and higher taxa consists of all the species that have evolved from one ancestral species helps to identify species and allows prediction of characteristics shared by a group of species |
| What is a taxon? (3) | Standard classification unit to group related organisms each taxon comes from a single ancestor more taxa organisms share, the more related they are |
| What are the characteristics of a scientific name of an organism? (3) | Genus is written first and is capitalised (Homo) Species is in lower case (sapiens) They can have a sub species name sometimes = Human |
| What is the full classification for humans? ACMPHHS | K = Animalia P = Chordata C = Mammalia O = Primate F = Hominidae G = Homo S = sapiens |
| What are dichotomous keys? (5) | A way of identifying whereby a group of organisms are divided into 2 categories until all the organisms are identified can be shown as a branched flowchart or with a series of statements in a numbered sequence Unchangeable characteristics should be used (number of legs) = size, color and behavior can change over time |
| What are the 4 Plant phyla? | Bryophyta Coniferophyta Filicinophyta Angiospermophyta |
| What are the 7 Animal Phyla? | Porifera Cnidaria Platyhelmintha Annelida Mollusca Arthropoda Chordata |
| What are the features of bryophyta? (7) | Don't have true roots or leaves no vascularisation (xylem and phloem) release sporangia to reproduce have a root like structure called rhizoid to anchor them Prevent flooding found in clumps in damp places like swamps EG: Mosses and liverworts |
| What are the features of filicinophyta? (6) | Vascular pinnate leaves no seeds shallow roots reproduce by spores on the underside of the leave (sori) EG: Ferns |
| What are the features of coniferophyta? (5) | Woody stems and waxy needlelike leaves vascular non motile seeds ( male and female cones) provide shelter EG: Pine trees |
| What are the features of angiospermophyta? (5) | Vascular reproduce by seeds in ovules (can become fruits) mono / dicotyledons transfer pollen from anther to stigma to reproduce EG: flowers and grasses |
| What are the features of porifera? (8) | Sponges full of water no mouth or anus calcium spicules for structure aquatic sessile (Stay in place) asymetrical reproduce by releasing egg and sperm separately / budding EG: sea sponges |
| What are the feature for cnidaria? (6) | Radial cnidocytes (tentacles with stinging cells) used for capturing prey mouth no anus corals secrete CaCO3 skeleton EG: anemones, jellyfish |
| What are the features of Platyhelminths? (5) | Flattened body shape (large S:vol ratio) mouth no anus bilateral can be parasitic and live within a host organism eg: tapeworms and planaria |
| What are the features of annelida? (5) | Bilateral ringed segments mouth and anus move by peristaltic contraction EG: earthworms and leeches |
| What are the features of mollusca? (7) | Bilateral mouth and anus visceral mass mantle muscular foot can have a shell eg: snails, octopi, clams |
| What are the features of arthropoda? (5) | Bilateral mouth and anus jointed segments hard chitin exoskeleton EG: spiders and scorpions |
| What are the features of chordata? (4) | All vertebrates bilateral mouth and anus notochord and hollow dorsal nerve tube = backbone |
| What are the features of fish? (6) | Covered in scales made out of bony plates external fertilisation breathe through gills ectothermic (doesn't maintain body temp) swim bladder EG: Zebrafish |
| What are the features of amphibians? (6) | Moist skin (permeable to gases and water) external fertilisation breathe through skin but also have simple lungs ectothermic larval in water and adult on land EG: frogs and salamanders |
| What are the features of reptiles? (7) | Covered in keratin scales soft shelled eggs internal fertilisation lungs with extensive folding ectothermic simple teeth EG: lizards |
| What are the features of birds? (6) | Covered in keratin feathers hard shelled eggs breathe through lungs with parabronchial tubes maintain body temp wings and beaks (no teeth) EG: sparrows |
| What are the features of mammals? (7) | Skin has keratin hair follicles live births internal fertilisation breathe through lungs with alveoli maintain body temp feed young with milk from mammary glands EG: elephants |
| What is a clade? | A group of organisms that evolved from one ancestor (node) clade members have common traits bec of a shared evolutionary lineage |
| What are cladograms? | Tree diagrams to show the most probable sequence of divergence in clades |
| How is evidence for which species are part of a clade found? | From the base sequence of a gene or the corresponding amino acid sequence of a protein |
| Why is their a positive correlation bw the no of differences bw 2 species and the time they diverged? | Because sequence difference build up gradually |
| What is phylogeny? | The evolutionary history of a particular species or group = shown as cladograms (tree diagrams) |
| What are cladograms based on? | Structural features (lungs, hair) or molecular features (sequences, mutations) |
| What is cladistics? | Determination of evolutionary relationships |
| What does each branch point represent? | A speciation event (Divergence) species with fewer branch points = more closely related |
| What are the limitations of using structural characteristics to compare species? (2) | 1) closely related organisms can show very diff features (homologous) bec of adaptive radiation = rapid divergence to suit ecological niches 2) distantly related organisms can show similar features (analogous) bec of convergent evolution =common selection pressures) |
| What are homologous structures? (4) | Same anatomy but with different functions shows that they share a common ancestor they have different functions bec of divergent evolution to suit diff ecological niches eg: lizards and birds have similar bon structures in the wings and feet |