Unit 4: Living organisms and classification
GRADE 6 – Unit 4: Living organisms and classification — HIA International - Grade 6 Revision Notes & Topical Questions
5 min read 7 parts Lesson 1 of 8 1 quiz
Lesson summary
Unit 4: Grouping and identifying organisms — HIA INTERNATIONAL notes: Summarise the characteristics of living organisms, viruses, species and the use and construction of dichotomous keys.CharacteristicMeaningNutritiontaking in or making food — plants feed by photosynthesis and an…
- Replication
- Living or non-living
- Own species only
- Fertile offspring
- Different species
- Definition
Section 1 of 7The seven characteristics
| Characteristic | Meaning |
|---|---|
| Nutrition | taking in or making food — plants feed by photosynthesis and animals such as bears eat food |
| Growth | young organisms get bigger |
| Movement | living organisms change the shape and position of their bodies |
| Sensitivity | organisms are sensitive to changes going on around them, such as the smell of meat sensed by a nose |
| Excretion | organisms get rid of waste materials, such as carbon dioxide breathed out by animals |
| Reproduction | organisms produce young, making more of the same kind of organism |
| Respiration | food is broken down inside cells to provide energy |
Section 2 of 7Viruses
Viruses
Structure
- Structure a virus is not made of cells and has RNA inside a protein coat with pegs
Replication
- Replication a virus can only replicate by getting inside a living cell
Living or non-living
- Living or non-living scientists disagree because viruses show no life processes outside a host cell
Section 3 of 7Species and reproduction
Own species only
- Own species only each species reproduces only with other members of its own species, and the offspring belong to the same species as their parents
Fertile offspring
- Fertile offspring offspring that can also produce offspring
Different species
- Different species organisms from different species cannot usually reproduce with one another
Definition
- Definition a species is a group of organisms that can reproduce together to produce fertile offspring
Section 4 of 7Using keys
Dichotomous key
- Dichotomous key a set of yes/no questions branching into two, used to identify an organism
Method
- Method start at the top, answer each question and follow the line until the name is reached
Section 5 of 7Constructing keys
Constructing keys
Method
- Method split the group in two, then split each smaller group in two until every organism has its own name
Features
- Features use clear features that give the same answer for everyone
Testing
- Testing ask another person to try the key and improve it with their feedback
Section 6 of 7Key terms
| Term | Meaning |
|---|---|
| Organism | A living thing. |
| Respiration | Breaking down food in cells to release energy. |
| Virus | A tiny particle with genetic material in a protein coat that replicates only inside living cells. |
| Species | A group of organisms that can reproduce together to produce fertile offspring. |
| Variation | Differences between organisms of the same species. |
| Dichotomous key | A key made of questions that branch into two. |
Section 7 of 7Exam technique
1
Saying living things must breathe or have a heartbeat — plants are alive without breathing or a heart
2
Confusing respiration with breathing — respiration is the breakdown of food inside cells to provide energy
3
Saying a virus can replicate on its own — it can only replicate inside a living cell
4
Saying lions and tigers are one species because they can reproduce — their offspring (ligers) are infertile
Marked practiceQuizzes for this lesson
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