BIOLOGY PRACTICAL ACTIVITIES
Examining the stages of mitosis
- About 2 mm of a root tip of onion bulb is cut off and placed on a microscope slide.
- A stain e.g. aceto-orcein is added and the root tip macerated using a scapel.
- A cover slip is added and observations made.
- Different stages of mitosis can be observed.
Table of Contents
Examining the stages of meiosis
- An unopened bud of Tradescantia is obtained
- The anther is removed and placed on a microscope slide.
- A few drops of hydrochloric acid and acetic-orcein stain are added.
- A cover slip is placed on the anther.
- Pressing the cover slip gives a thin squash, which is observed under the microscope.
- Different stages of meiosis are observed.
To observe the structure of Rhizopus
- Rhizopus grow on moist bread left under suitable temperature
- A piece of moist bread is placed on a petri¬-dish or enclosed in a plastic bag and observe daily for four days.
- Under a low power microscope the sporangia and stolons can be observed.
To examine spores on sori of ferns
- Obtain the fern plant.
- Detach a frond from the plant and observe the under-side using a hand lens to see the raised brown patches – the sori.
- Open up the sorus to observe the sporangia.
Examine insect and wind pollinated flowers
- Obtain insect pollinated flowers e.g. crotalaria, hibiscus/Ipomea, Solanum, incunum.
- Note the scent, colour and nectar guides.
- A description of the calyx, corolla, androecium and gynoecium is made.
- Obtain a wmd pollinated flower e.g,’ maize, star-grass, sugar-cane, Kikuyu grass.
- Observe the glumes, spikes and spikelet.
- Examine a single floret, and identify the androecium and gynoecium.
- Obtain different fruits – oranges, mangoes, maize, castor oil, bean pod, black jack .
- Observe the fruits, classify them into succulent, dry-dehiscent or indehiscent.
Dissection of Fruits
- Obtain an orange and a mango fruit.
- Make a transverse section.
- Observe the cut surface and draw and label the parts.
- Note that the fruit is differentiated into epicarp, mesocarp and endocarp.
- Obtain a pod of a legume.
- Open up the pod and observe the exposed surface.
- Draw and label the parts.
- Note that the fruit wall is not differentiated.
Dispersal of fruits and seeds
- Obtain animal dispersal fruits, like oranges, tomatoes, black jack, sodom apple.
- Identify the way by which each is adapted to dispersal by animals.
- Obtain wind dispersed fruit/seed e.g. Nandi flame, Jacaranda Sonchus, cotton seed, Tecoma.
- How do you identify the stages of mitosis?
- What are the 5 stages of mitosis and what is occurring at each?
- What is a good way to remember the stages of mitosis?
- How do you identify the stages of meiosis?
- What are the 5 stages of meiosis?
- What are the 4 stages of the cell cycle?
- How can you observe the structure of Rhizopus?
- What is the structure of Rhizopus?
- How do you observe spore in fern leaves?
- What is sori in ferns?
- How will you describe spores?
- What is the difference between insect and wind pollinated flowers?
- What are characteristics of wind water and insect pollinated flowers?