Topic 9.3: Reproduction in angiospermophytes

9.3.1 Draw and label a diagram showing the structure of a dicotyledonous animal-pollinated flower

9.3.2 Distinguish between pollination, fertilization and seed dispersal

9.3.3 Draw and label a diagram showing the external and internal structure of a named dicotyledonous seed

9.3.4 Explain the conditions needed for the germination of a typical seed

9.3.5 Outline the metabolic processes during germination of a starchy seed

9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome

Topic 9.2: Transport in angiospermophytes

9.2.1 Outline how the root systems provides a large surface area for mineral ion and water uptake by means of branching and root hairs

9.2.2 List ways in which mineral ions in the soil move to the roots

9.2.3 Explain the process of mineral ion absorption from the soil into roots by active transport

9.2.4 State that terrestrial plants support themselves by means of thickened cellulose, cell turgor and lignified xylem

9.2.5 Define transpiration

9.2.6 Explain how water is carried by the transpiration stream, including the structure of xylem vessels, transpiration pull, cohesion, adhesion and evaporation

9.2.7 State that guard cells can regulate transpiration by opening and closing stomata

9.2.8 State that the plant hormone abscisic acid causes the closing of stomata

9.2.9 Explain how abiotic factors light, temperature, wind and humidity affect the rate of transpiration in a typical terrestrial plant

9.2.10 Outline four adaptations of xerophytes that help to reduce transpiration

9.2.11 Outline the role of phloem in active translocation of sugars (sucrose) and amino acids from source (photosynthetic tissue and storage organs) to sink (fruits, seeds and roots)

Topic 9.1: Plant structure and growth

9.1.1 Draw and label plan diagrams to show the distribution of tissues in the stem and leaf of a dicotyledonous plant

9.1.2 Outline three differences between the structures of dicotyledonous and monocotyledonous plants 

9.1.3 Explain the relationship between the distribution of tissues in the leaf and the functions of these tissues

9.1.4 Identify modifications of roots, stems and leaves for different functions: bulbs, stem tubers, storage roots and tendrils

9.1.5 State that dicotyledonous plants have apical and lateral meristerms 

9.1.6 Compare growth due to apical and lateral meristerms in dicotyledonous plants

9.1.7 Explain the role of auxin in phototropism as an example of the control of plant growth

Topic 9: Plant science

Topic 9 of the IB HL Biology syllabus is the Plant science. IBO recommends to spend 11 hours on this topic.

This topic has 3 sub-chapters: "Plant structure and growth", "Transport in angiospermophytes" and "Reproduction in angiospermophytes". Each are separated with numerical values in order of mentioned.

These are all HL syllabus statements, it is recommended to bring a Casio Graphical Calculator instead of Texas.

Topic 5.5: Classification

5.5.1 Outline the binomial system of nomenclature

5.5.2 List seven levels in the hierarchy of taxa - kingdom, phylum, class, order, family, genus and species - using an example from two different kingdoms for each level

5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta

5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda

5.5.5 Apply and design a key for a group of up to eight organisms

Topic 5.4: Evolution

5.4.1 Define evolution

5.4.2 Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures

5.4.3 State that populations tend to produce more offspring than the environment can support

5.4.4 Explain that the consequence of potential overpopulation of offspring is a struggle for survival

5.4.5 State that the members of a species show variation

5.4.6 Explain how sexual reproduction promotes variation in a species

5.4.7 Explain how natural selection leads to evolution

5.4.8 Explain two examples of evolution in response to environmental changes; one must be antibiotic resistance in bacteria

Topic 5.3: Populations

5.3.1 Outline how population size is affected by natality, immigration, mortality and emigration

5.3.2 Draw and label a graph showing a sigmoid (S-shaped) population growth curve

5.3.3 Explain the reasons for the exponential growth phase, the plateau phase and the transitional phase between these two phases

5.3.4 List three factors that set limits to population increase

Topic 5.2: The greenhouse effect

5.2.1 Draw and label a diagram of the carbon cycle to show the processes involved

5.2.2 Analyse the changes in concentration of atmospheric carbon dioxide using historical records

5.2.3 Explain the relationship between rises in concentration of atmospheric carbon dioxide, methane and oxides of nitrogen and enhanced greenhouse effect.

5.2.4 Outline the precautionary principle

5.2.5 Evaluate the precautionary principle as a justification for strong action in response to the threats posed by enhanced greenhouse effect

5.2.6 Outline the consequences of a global temperature rise on arctic ecosystems

Topic 5.1: Communities and ecosystems

5.1.1 Define species, habitat, population, community, ecosystem and ecology

Species is a group of organisms that can interbreed and produce fertile, viable offspring

Habitat is an environment in which a species normally lives or the location of a living organism

Population is a group of organism of the same species who live in the same area at the same time

Community is a group of populations living and interacting with each other in an area

Ecosystem is a community and its abiotic environment

Ecology is the study of relationships between living organisms and between organisms and their environment.

5.1.2 Distinguish between autotroph and heterotroph

Autotroph is an organism that synthesizes its organic molecules from simple inorganic substances such as carbon dioxide and nitrates. Autotroph are producers.

Heterotroph is an organism that obtains organic molecules from other organisms. Heterotroph are consumers.

5.1.3 Distinguish between consumers, detritivores and saprotrophs

Consumers is an organism that ingests other organic matter that is living or recently killed

Detritivore is an organism that ingest non-living organic matter

Saprotroph is an organism that lives on or in non-living organic matter, secreting digestive enzymes into and absorbing products of digestion

5.1.4 Describe what is meant by a food chain, giving three examples, each with at least three linkages (four organisms)

A food chain shows the linear feeding relationship between species in a community. An arrow is commonly used to represent the transfer of energy. Thus the arrow is pointing towards the consumer.

5.1.5 Describe what is meant by a food web

A food web is a diagram that shows multiple food chains together. It shows a more complete and complex feeding relationships within a community.

5.1.6 Define trophic level

An organisms trophic level refers to the position they are in on the food chain. Refer to the diagram below.

5.1.7 Deduce the trophic level of organisms in a food chain and a food web

An organism can have multiple trophic level. Find the trophic levels by counting how many past

5.1.8 Construct a food web containing up to 10 organisms, using appropriate information



5.1.9 State that light is the initial energy source for almost all communities



5.1.10 Explain the energy flow in a food chain



5.1.11 State that energy transformations are never 100% efficient



5.1.12 Explain reasons for the shape of pyramids of energy



5.1.13 Explain that energy enters and leaves ecosystems, but nutrients must be recycled



5.1.14 State that saprotrophic bacteria and fungi (decomposers) recycle nutrients

Topic 5: Ecology and evolution

Topic 5 of the IB SL Biology syllabus is the Ecology and evolution. IBO recommends to spend 16 hours on this topic.

This topic has 5 sub-chapters: "Communities and ecosystems", "The greenhouse effect", "Populations", "Evolution", and "Classification". Each are separated with numerical values in order of mentioned.

These are all SL syllabus statements, it is recommended to bring a Casio Graphical Calculator instead of Texas.