Week 8 Classification, Fertilisation and Development
Task 1
Refer to your “Flower Observation Spreadsheet”.
Use this data to construct a dichotomous key.
DICHOTOMOUS KEYS
The word ‘dichotomous’ means ‘split in two parts’. In a dichotomous key, you always select from two choices. In this key, you decide whether an organism has or doesn’t have a particular feature.
Examine the dichotomous key below.
Use this data to construct a dichotomous key.
DICHOTOMOUS KEYS
The word ‘dichotomous’ means ‘split in two parts’. In a dichotomous key, you always select from two choices. In this key, you decide whether an organism has or doesn’t have a particular feature.
Examine the dichotomous key below.
- What patterns do you see?
- How alike are the animals in each group?
- What do the words general and specific mean?
- Why do we classify organisms? Refer to Science ASpects 1 page 19
Classification Keys - From Science Aspects 1 page 19
Keys can be constructed in any way by anyone who needs to identify something. The features used in the key can be anything, but they will work best if they satisfy the following rules:
1 The feature must be easy to observe. It is pointless using a feature that is very difficult to see or detect.
2 The feature must be used accurately and reliably by those who use the key. The key would not work if different people using it did not make the same choices. For example, if the key was for plants, and the feature chosen gave a choice of colours, such as light green, blue-green or yellow-green, different people may not place a particular plant in the same group. This is because people often differ in their ideas about colour.
Task 1 Consolidation - Classification Using Dichotomous Keys
Science Aspects 1 page 19 Do Questions 1 to 5
Keys can be constructed in any way by anyone who needs to identify something. The features used in the key can be anything, but they will work best if they satisfy the following rules:
1 The feature must be easy to observe. It is pointless using a feature that is very difficult to see or detect.
2 The feature must be used accurately and reliably by those who use the key. The key would not work if different people using it did not make the same choices. For example, if the key was for plants, and the feature chosen gave a choice of colours, such as light green, blue-green or yellow-green, different people may not place a particular plant in the same group. This is because people often differ in their ideas about colour.
Task 1 Consolidation - Classification Using Dichotomous Keys
Science Aspects 1 page 19 Do Questions 1 to 5
Task 2 Homework Book - bring to class
Complete Activities 4.8, 4.9 and 4.10
Task 3 Pollination, Fertilisation and Development
Complete Homework Book Activity 4.5
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Task 4 Cycle of Life
- Use the Cycle of Life template and the samples. Classify the flowers, fruits and seeds according to their developmental stage.
- Use a sharp pencil to draw and label the samples. Since we have to share our specimens draw the outside structures of each fruit; bean, apple, banana, strawberry and lemon before we dissect them.
- Labels include flower bud, flower, anther, pollen, stigma, style, ovary, ovule, fruit, seed, embryo, withered stigma, withered style, withered petals, withered stamens.
Task 6 Cycle of Life -due Monday 10 December
At home choose a different fruit to draw.
Find and label the withered stigma, withered stamens, withered petals, ovary (fruit), ovules (seeds) and if possible the ovum (embryo). Take care if you are cutting fruit.
Some seeds like peach seeds will be too hard to cut with a knife. You can research the structures inside.
Find and label the withered stigma, withered stamens, withered petals, ovary (fruit), ovules (seeds) and if possible the ovum (embryo). Take care if you are cutting fruit.
Some seeds like peach seeds will be too hard to cut with a knife. You can research the structures inside.