Biodiversity and Natural Resources | Edexcel A-Level Biology A (Salters-Nuffield) (9BN0)

Biodiversity and Natural Resources

287 questions
20 subtopics
Topics 1 to 4, examined on all three papers
Paper 1, Paper 2 and Paper 3

Covers the variety of life and how it arises: measuring biodiversity, natural selection and speciation, classification, the structure and uses of plant tissues, and the testing of drugs and antimicrobials..

It covers biodiversity, species richness and the index of diversity, niches and the three kinds of adaptation, natural selection and evolution, the Hardy-Weinberg equation and its assumptions, reproductive isolation and speciation, classification, the plant cell wall, chloroplast and amyloplast, the vacuole, plasmodesmata, pits and middle lamella, plant cells in the electron microscope, starch and cellulose, lignin, xylem vessels and sclerenchyma fibres, identifying plant tissues under the microscope, the structure of xylem, phloem and sclerenchyma, water and the mineral nutrition of plants, core practical: investigating mineral deficiency, core practical: the tensile strength of plant fibres, drug development from Withering to modern trials, growing bacteria and aseptic technique, core practical: the antimicrobial properties of plants and sustainability and Conservation.

Sample questions from Biodiversity and Natural Resources

Answer each one closed book first, then open the answer.

Biodiversity, species richness and the index of diversity

State the formula for calculating the heterozygosity index (H).

Show the answer
H = number of heterozygotes ÷ total number of individuals in the population.
Natural selection and evolution

What is evolution?

Show the answer
Evolution is the cumulative change in the heritable characteristics of a population over successive generations.
Classification

Which domain contains prokaryotes that often live in extreme environments and lack peptidoglycan in their cell walls?

Show the answer
Archaea.
The vacuole, plasmodesmata, pits and middle lamella

What is the desmotubule?

Show the answer
A central strand of endoplasmic reticulum that runs through the plasmodesma.
Lignin, xylem vessels and sclerenchyma fibres

Why is the pattern of lignin deposition in xylem vessels advantageous?

Show the answer
It provides support while allowing some flexibility and lateral water movement.
The structure of xylem, phloem and sclerenchyma

State the function of sclerenchyma fibres.

Show the answer
Mechanical support of the plant.
Core practical: the tensile strength of plant fibres

What value is recorded when testing tensile strength of a fibre?

Show the answer
The load at which the fibre breaks.
Growing bacteria and aseptic technique

How can equipment be sterilised as part of aseptic technique?

Show the answer
By using an autoclave or by flaming.

The 20 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Biodiversity, species richness and the index of diversity	Recall questions on endemism, species richness, the heterozygosity index and the index of diversity, and on what each measures.	19
Niches and the three kinds of adaptation	Recall questions on what a niche includes, and on behavioural, physiological and anatomical adaptations.	13
Natural selection and evolution	Recall questions on variation, selective advantage, and how natural selection changes allele frequencies over time.	8
The Hardy-Weinberg equation and its assumptions	Recall questions on the two Hardy-Weinberg equations, what each term represents, the assumptions the model makes, and how it is used to test for evolution.	22
Reproductive isolation and speciation	Recall questions on how isolation stops gene flow, and on how accumulated differences produce a new species.	9
Classification	Recall questions on classifying organisms by phenotype and genotype, how scientists scrutinise new data, molecular phylogeny and Woese’s three domains, the taxonomic ranks, the biological and morphological species concepts and their limits, and the use of DNA evidence.	28
The plant cell wall, chloroplast and amyloplast	Recall questions on cellulose in the cell wall, the membranes, thylakoids, grana and stroma of the chloroplast, and the role of amyloplasts.	14
The vacuole, plasmodesmata, pits and middle lamella	Recall questions on turgor and the tonoplast, and on plasmodesmata, pits and the middle lamella.	16
Plant cells in the electron microscope	Recall questions on how each plant structure appears in an electron micrograph.	11
Starch and cellulose	Recall questions on amylose and amylopectin, how alpha and beta glucose differ, and why cellulose microfibrils are strong.	12
Lignin, xylem vessels and sclerenchyma fibres	Recall questions on secondary thickening, the patterns of lignin deposition, and the structure and function of xylem vessels and sclerenchyma.	11
Identifying plant tissues under the microscope	Recall questions on recognising xylem, phloem and sclerenchyma, and on the arrangement of vascular bundles.	9
The structure of xylem, phloem and sclerenchyma	Recall questions on which of these cells are living at maturity, their wall composition, and what each transports or supports.	21
Water and the mineral nutrition of plants	Recall questions on the roles of water in a plant, and on the functions and deficiency symptoms of nitrate, calcium and magnesium.	12
Core practical: investigating mineral deficiency	Recall questions on preparing deficient culture solutions, the variables controlled, and the observations recorded.	8
Core practical: the tensile strength of plant fibres	Recall questions on the method, the tensile strength formula, and the variables that must be controlled.	13
Drug development from Withering to modern trials	Recall questions on William Withering and digitalis, placebos and double blind design, and the three phases of a modern trial.	15
Growing bacteria and aseptic technique	Recall questions on the conditions bacteria need, obligate and facultative anaerobes, and the steps of aseptic technique.	13
Core practical: the antimicrobial properties of plants	Recall questions on the filter paper disc method, the zone of inhibition, controls, and laboratory safety rules.	13
Sustainability and Conservation	Recall questions on seed banks, captive breeding and other conservation methods, and on what makes resource use sustainable.	20

Biodiversity and Natural Resources is 287 of the 1,892 questions in the guide.Get the guide, £8

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.