Isolation is important for evolution because it decreases the size of the gene pool. This stops new alleles coming in from breeding with original alleles and speeds the accumulation of new mutations (which is what leads to speciation). The different types of isolation:
Evolution is a theory, not a fact. Many people believe that species were created (creationism). Other people believe in evolution, but by mechanisms other than Natural Selection. You should respect the opinions of other people, even if you do not necessarily agree...
Primary succession is the first stage of the ecological succession of plant life from abiotic land with no soil to fully support plant ecosystems (e.g., a forest). In primary succession, pioneer plants like mosses and lichen, start to "normalize" the habitat, creating...
Zoos can play a large role in conserving endangered species by; 1. Conducting research 2. Running captive breeding programmes 3. Reintroducing species into the wild 4. Educating people Research enables scientists to understand the role of a species in an ecosystem. By...
There are no set facts to learn.
There are no set facts to learn.
NPP = Net Primary Productivity (amount of stored chemical energy the plant has to use for growth. This is directly proportional to biomass) GPP = Gross Primary Productivity (amount of stored chemical energy the plant earns through photosynthesis) R = Respiration...
Energy is lost between trophic levels. Energy is lost in the following ways; in respiration (mostly lost through heat), energy still present in egested food, through movement, through digestion, energy still present in excreted materials etc Of the 100% sunlight...
Evolution: the idea that one species changes into another over time Natural Selection: Darwin’s suggestion for the process by which evolution might occur Evolution by Natural Selection (Darwinian Evolution) 1. There is variation in a species 2. More individuals are...
1798 Malthus publishes paper on population growth. Malthus noticed that the human population was expanding exponentially. He thought that the human population would outgrow its resources and that this would lead to famine and war. Darwin was influenced by this idea,...
There are three steps in the Calvin Cycle; 1. Carboxylation: RuBP fixes CO2to form GP. This reaction is catalysed by the enzyme Rubisco 2. Reduction: In a series of reactions GP reacts with ATP and NADPH reduced GP to form GALP (by reducing GP the NAHPH itself is...
Thylakoid membrane = location of photosystems & electron transport chain Stroma = site of Calvin Cycle & photolysis of water Grana provide large surface area for absorbtion of light
Dihybrid Crosses are for crosses involving two different genes (2 loci). A = Purple stem, a = Green Stem, D = Big Leaves, d = little leaves F1 Phenotype: 9 : 3 : 3 : 1 A_B_ : A_bb : aaB_ : aabb Purple & Big : Purple & Little : Green & Big : Green &...
Biotic Factor: A living variable within the ecosystem, which affects the survival of organisms. Examples include predation, competition, and pollution from excreted waste. Abiotic Factor: A non-living variable within the ecosystem, which affects the survival of...
Figure 5.33 – in the light dependant reactions of photosynthesis, the energy from the sun excites chlorophyll molecules. High energy electrons leave the chlorophyll and pass along a series of carrier proteins in the electron transport chain. The ionised chlorophyll...
Individuals in the same species look different (have different phenotypes). This is called variation. Variation is caused by; The genotype of the individual (i.e. which alleles they have). The environment. Genetic diversity describes the range of different genotypes...
A particular species can be identified using the features (the phenotype) which are characteristic to only that species. Species with similar phenotypes are likely to be related to each other. A key of characteristics is used to identify the species. (see p10 – 11)...