Biology Learning and Assessment Notes
Introduction to Biology
- Biology is the study of living things.
- Definition of life is complex and subjective.
- Engage with peers to define life and identify common features in living organisms (e.g. plants, animals, bacteria, fungi).
- Consider non-living entities mistaken for life (e.g. fire, computer viruses).
Habits for Effective Learning
- Outline strategies for studying biological concepts effectively.
MRS GREN: Life Processes
- Acronym MRS GREN stands for:
- Movement
- Respiration
- Sensitivity
- Growth
- Reproduction
- Excretion
- Nutrition
- Each life process relates to biochemical reactions that must be regulated and self-sustaining in living organisms.
Life Process Overview
| Life Process | Organism Example | Individual Cell Example |
|---|
| Controlled exchange of materials | - e.g. Oxygen uptake | - e.g. Nutrient absorption |
| Maintaining a stable internal environment | - e.g. Thermoregulation | - e.g. Homeostasis in cells |
| Obtaining energy and chemical elements | - e.g. Photosynthesis in plants | - e.g. Cellular respiration |
| Transport of materials | - e.g. Blood circulation in animals | - e.g. Vesicle transport in cells |
| Removal of waste | - e.g. Exhalation of CO2 | - e.g. Waste expulsion through cell membrane |
| Growth and development | - e.g. Maturation of a butterfly | - e.g. Cell division and growth |
| Reproduction | - e.g. Plant seeds dispersing | - e.g. Binary fission in bacteria |
Cell Theory
- All living things are composed of one or more cells.
- Cells are the smallest units of life – they carry out life processes independently.
- New cells arise only from pre-existing cells.
Structure of Cells
- Definition:
- A cell consists of cytoplasm enclosed within a cell membrane; cytoplasm contains organelles and fluids necessary for life functions.
Unicellular Organisms
- Definition: Organisms consisting of only one cell, referred to as microbes.
- Functionality: The single cell must perform all essential life processes independently.
Multicellular Organisms
- Definition: Living entities made of many cells working together.
- Specialisation: Cells differentiate to undertake specific roles; human body has around 200 different cell types.
- Examples: Animals, plants, fungi (excluding yeast).
Viruses and Life
- Definition: A virus contains genetic material surrounded by a protein coat and needs a host cell to reproduce.
- Controversy: Viruses do not perform life processes independently, leading many biologists to classify them as non-living entities.
Review of Previous Knowledge
- Recall information on organelles and cell types learned in Year 8.
- Differentiate between plant and animal cells – identifying key features.
- List organelles present in various cell types.
- Research specialized plant and animal cells; include images and note structural differences.