Things to Remember VCE Biology

General SAC Tips

Biological DrawingsFull intact cell always to be drawn

Answering Questions Get to the point of the question Use dot points When asked to Describe -> describe what is going on in the picture/diagram not why it is happenig Use terminology Do not give more than one answer/ do not contradict yourself Draw diagrams

Reading Questions Diagrams -> think from the examiner's point of view, figure out what it is conveying Read question and highlight points

Answering using graphs Quote numbers from the graph Use technical language like plateau for a flat line State general trends Use annotations

Experimental Design

Variables Shown on graph axis if provided Independent variable - what you are changing Dependent variable - what you are measuring as a result of that change Controlled variables - remain the same in all set applications Control group - a comparison for the results/how/show the results are due to the change in the independent variable, multiple control groups are needed with or without independent variables if it cannot be removed showing different levels

Hypothesis If/then relationship showing cause and effect Independent and dependent variable Method Annotated diagram - explains through detailed instructions concerning quantities like time and amount, set up, observations, tables and collection of results Repetition of experiment multiple times - reducing the change of error effecting the outcome Results Quantitative -> preferred as it is less objective and not biased Qualitative -> subjective

Movement of Molecules

Import and Export of Molecules into and Out of the CellActive transport - Ions like sodium and calcium are transported using active transport if concentrations are different

Interpreting Percentage Change Graphs No % change equals the same concentration inside and outside the cell The cell is isotonic

Identifying changes in CellsState in terms of has become more flaccid and turgid and state the reason why this is thought to be so (boundary moved further away from cell wall)

Enzymes

Important Details Enzyme are not used up in the process of a chemical reaction Enzymes catalyse reactions by destabilising bonds in the substrate so that it is more reactive

Biochemical Processes

General When asked to describe some energy conversions, refer to cellular respiration and photosynthesis Endergonic or exergonic - refer to the breakdown or formation of chemical bonds ATP to ADP - describe the cycle

Cellular RespirationMany cells can carry out anaerobic and aerobic respiration at the same time

Samples of Good Answers

Identify the type of chromosomal abnormality involved and the error in cell division which most likely gave rise to the abnormality.Aneuploidy - one extra chromosome present in the cell, specifically trisomyNon-disjunction - during nuclear division one pair of chromatids was not separated during anaphase

Explain why there is a difference in the way the bacteria have grown on plates A and C Plate C - only some bacteria transformed Discrete colonies - only transformed bacteria grow because resistant to copper Plate A = all bacteria grown hence continuous growth due to no copper inhibition

Mitosis and Meiosis

A replicated chromosome has two chromatids, double stranded chromosome but when they separate, they are no longer called chromatids but single stranded chromosomes. Homologous chromosomes have the same gene loci - terminology For familial Downs' Syndrome, the offspring that survive include two normal phenotypes, one with a translocated chromosome and one with no unusual chromasomes (normal) and one Downs' Syndrome phenotype with an extra chromosome 21

Inheritance

A large difference in expected phenotypic ratio can be due to how the phenotype is affected by the environment The dihybrid cross punnet square quick method = 9 dominant, dominant: 3 dominant, recessive: 3 recessive, dominant: 1 recessive, recessive

Pedigree Key show with and without disease for males and females -> therefore 4 keys Usually shade in the disorder