Planning Investigations in Biology Kukonzekera Kafukufuku wa Sayansi (Planning Investigations in Biology)
Biology is a subject that helps us understand the living world around us , from the fish in Lake Malawi to the crops growing in our fields. But how do biologists discover new facts about living things? They do so through scientific investigations. A scientific investigation is a systematic, organised process used to answer questions about the natural world. Rather than guessing or relying on opinions, scientists follow a careful series of steps to find evidence-based answers.
Every scientific investigation begins with a question or a problem. For example, a student in Lilongwe might notice that maize plants growing near a window are taller than those growing in a dark corner of the classroom. This observation leads to a question: “Does the amount of light affect the growth of maize plants?” Asking clear, specific questions is the first step in planning any investigation.
Once you have a question, the next step is to form a hypothesis. A hypothesis is a testable prediction , an educated guess about what you think will happen and why. For our maize plant example, a hypothesis might be: “If maize plants receive more sunlight, then they will grow taller, because light provides energy for photosynthesis.” A good hypothesis is always written in a way that can be tested through an experiment. It should be specific and include a reason for the prediction.
After forming a hypothesis, you must identify your variables. Variables are factors that can change in an experiment. There are three types of variables you need to understand:
Independent variable , This is the variable that you deliberately change in the experiment. It is the factor you are testing. In our example, the independent variable is the amount of light the plants receive.
Dependent variable , This is the variable that you measure or observe. It changes as a result of the independent variable. In our example, the dependent variable is the height of the maize plants.
Controlled variables , These are all the other factors that you keep the same so that the test is fair. In our example, controlled variables include the type of soil, the amount of water given, the type of maize seeds used, the size of the pots, and the temperature of the environment.
Understanding variables is essential because of the concept of a fair test. A fair test means that you only change one variable at a time (the independent variable) while keeping everything else the same. If you changed both the amount of light and the amount of water at the same time, you would not know which factor caused any difference in plant growth. A fair test allows you to draw valid conclusions.
The next step in planning is to choose the appropriate apparatus and materials. For the maize investigation, you would need items such as maize seeds, planting pots, soil, a ruler for measuring height, water, and areas with different light levels. In Malawi, many biology investigations can be carried out using locally available materials , you do not always need expensive laboratory equipment.
Finally, you must write a clear method or procedure. This is a step-by-step plan that explains exactly what you will do, in the order you will do it. A good method is so clear that another student could follow it and repeat your experiment. It should include details about how you will set up the experiment, how often you will take measurements, and how long the experiment will last.
Let us consider another example relevant to Malawi. Suppose you want to investigate whether the type of water (tap water, borehole water, or Lake Malawi water) affects the germination of bean seeds. You would plan as follows:
Question: Does the type of water affect the germination of bean seeds?
Hypothesis: Bean seeds watered with tap water will germinate faster than those watered with borehole water or Lake Malawi water, because tap water may contain fewer dissolved minerals that could inhibit germination.
Independent variable: Type of water (tap, borehole, Lake Malawi)
Dependent variable: Number of seeds that germinate after 7 days
Controlled variables: Number of seeds, amount of water given, type of soil, temperature, container size
Apparatus: Bean seeds, three containers, soil, measuring cylinder, tap water, borehole water, Lake Malawi water, labels
Method: Plant 10 bean seeds in each of three identical containers with the same soil. Water each container daily with 50 ml of a different type of water. Place all containers in the same location. Count the number of germinated seeds each day for 7 days. Record results in a table.
Planning an investigation thoroughly before you begin saves time, reduces mistakes, and helps ensure that your results are meaningful and reliable.
Nthawi: Mphindi 40
Sayansi ya zamoyo (Biology) ndi phunziro limene limatithandiza kumvetsetsa dziko la zamoyo lotizungulira , kuyambira nsomba za m’nyanja ya Malawi mpaka mbewu zomera m’minda yathu. Koma kodi akatswiri a sayansi ya zamoyo amapeza bwanji zidziwitso zatsopano? Amapeza kudzera mu kafukufuku wa sayansi. Kafukufuku wa sayansi ndi njira yokonzeka bwino yomwe imagwiritsidwa ntchito poyankha mafunso okhudza dziko la chilengedwe. M’malo mongoyerekeza kapena kudalira maganizo awo okha, asayansi amatsatira njira yapadera kuti apeze mayankho othandizidwa ndi umboni.
Kafukufuku uliwonse wa sayansi umayamba ndi funso kapena vuto. Mwachitsanzo, wophunzira wina ku Lilongwe angaone kuti mbewu za chimanga zomera pafupi ndi zenera n’zozitali kuposa zomera kumalo a mdima m’kalasi. Kuona kumeneku kumabweretsa funso lakuti: “Kodi kuchuluka kwa kuwala kumasokoneza kukula kwa mbewu za chimanga?” Kufunsa mafunso oyenera ndi omveka bwino ndi sitepe yoyamba pakukonzekera kafukufuku uliwonse.
Mutapeza funso, sitepe yotsatira ndi kupanga chikhazikitso (hypothesis). Chikhazikitso ndi choyerekeza chomwe chingathe kuyesedwa , kuganiza mozama za zomwe mukuyembekezera kuti zichitike ndiponso chifukwa chake. Pa chitsanzo chathu cha chimanga, chikhazikitso chingakhale choti: “Ngati mbewu za chimanga zilandira dzuwa lambiri, ndiye kuti zidzakula mozitali, chifukwa kuwala kumapereka mphamvu ya photosynthesis.” Chikhazikitso chabwino chimayenera kulembedwa m’njira yomwe ingayesedwe kudzera mu kafukufuku. Chiyenera kukhala chodziwitsa ndiponso kuphatikiza chifukwa cha choyerekeza chake.
Mutapanga chikhazikitso, muyenera kuzindikira zosintha (variables) zanu. Zosintha ndi zinthu zomwe zingasinthe mu kafukufuku. Pali mitundu itatu ya zosintha yomwe muyenera kumvetsetsa:
Chosintha chodziyimira (Independent variable) , Ichi ndi chosintha chomwe mumasintha dala mu kafukufuku. Ndi chinthu chomwe mukuyesa. Mu chitsanzo chathu, chosintha chodziyimira ndi kuchuluka kwa kuwala komwe mbewu zimalandira.
Chosintha chodalira (Dependent variable) , Ichi ndi chosintha chomwe mumayeza kapena kuona. Chimasintha chifukwa cha chosintha chodziyimira. Mu chitsanzo chathu, chosintha chodalira ndi msinkhu wa mbewu za chimanga.
Zosintha zoyanganiridwa (Controlled variables) , Izi ndi zinthu zonse zomwe mumasunga zofanana kuti kuyesedwa kukhale kosalakwika. Mu chitsanzo chathu, zosintha zoyanganiridwa zimaphatikiza mtundu wa dothi, kuchuluka kwa madzi operekedwa, mtundu wa mbewu za chimanga zogwiritsidwa ntchito, kukula kwa mbale, ndi kutentha kwa malo.
Kumvetsetsa zosintha ndikofunikira kwambiri chifukwa cha lingaliro la kuyesedwa kosalakwika (fair test). Kuyesedwa kosalakwika kumatanthauza kuti mumasintha chosintha chimodzi chokha panthawi imodzi (chosintha chodziyimira) pamene zinthu zonse zina zimasungidwa zofanana. Mukasintha kuchuluka kwa kuwala ndi kuchuluka kwa madzi nthawi imodzi, simungathe kudziwa chifukwa chake chimene chinabweretsa kusiyana pakukula kwa mbewu. Kuyesedwa kosalakwika kumathandiza kupeza mathero ovomerezeka.
Sitepe yotsatira pakukonzekera ndi kusankha zida ndi zipangizo zoyenera. Pa kafukufuku wa chimanga, mungafunikire zinthu monga mbewu za chimanga, mbale zodzalira, dothi, rula woyezera msinkhu, madzi, ndi malo okhala ndi kuwala kosiyanasiyana. Ku Malawi, kafukufuku wambiri wa sayansi ya zamoyo akhoza kuchitidwa pogwiritsa ntchito zipangizo zomwe zimapezeka m’dera , simungafunikirenso zipangizo za mtengo wapatali za ku laboreteri nthawi zonse.
Pomaliza, muyenera kulemba njira (method) yomveka bwino. Iyi ndi ndondomeko ya sitepe ndi sitepe yomwe imafotokoza momveka bwino zomwe mudzachite, mu dongosolo lomwe mudzachitire. Njira yabwino imakhala yomveka kwambiri moti wophunzira wina akanatha kuitsatira ndi kubwereza kafukufuku wanu. Iyenera kuphatikiza ndondomeko ya momwe mudzakonzekere kafukufuku, kangati mudzayeze, ndi nthawi yaitali bwanji kafukufuku adzatenga.
Tiyeni tione chitsanzo china chokhudzana ndi Malawi. Tiyerekeze kuti mukufuna kufufuza ngati mtundu wa madzi (madzi a mpopi, madzi a mchere, kapena madzi a Nyanja ya Malawi) umasokoneza kumera kwa mbewu za nyemba. Mukonzekera motere:
Funso: Kodi mtundu wa madzi umasokoneza kumera kwa mbewu za nyemba?
Chikhazikitso: Mbewu za nyemba zothiridwa ndi madzi a mpopi zidzamera msanga kuposa zothiridwa ndi madzi a mchere kapena madzi a Nyanja ya Malawi, chifukwa madzi a mpopi akhoza kukhala ndi mchere wochepa womwe ungalepheretse kumera.
Chosintha chodziyimira: Mtundu wa madzi (mpopi, mchere, Nyanja ya Malawi)
Chosintha chodalira: Chiwerengero cha mbewu zomwe zamera patatha masiku 7
Zosintha zoyanganiridwa: Chiwerengero cha mbewu, kuchuluka kwa madzi, mtundu wa dothi, kutentha, kukula kwa chotengera
Zida: Mbewu za nyemba, zotengera zitatu, dothi, silinda woyezera, madzi a mpopi, madzi a mchere, madzi a Nyanja ya Malawi, matikiti olembera
Njira: Bzalani mbewu za nyemba 10 mu zotengera zitatu zofanana zokhala ndi dothi lofanana. Thirani chotengera chilichonse tsiku lililonse ndi madzi 50 ml a mtundu wosiyana. Ikani zotengera zonse pamalo amodzi. Werengerani mbewu zomera tsiku lililonse kwa masiku 7. Lembani zotsatira m’tebulo.
Kukonzekera kafukufuku bwino musanayambe kumapulumutsa nthawi, kumachepetsa zolakwika, ndipo kumathandiza kuonetsetsa kuti zotsatira zanu ndi zothandiza ndi zodalirika.
Exercise RequiredMasewera Ofunikira
You must pass this exercise to complete the lesson. Questions are randomly selected each attempt. Muyenera kupambana masewera awa kuti mumaliza phunziro. Mafunso amasankhidwa mwachisawawa nthawi iliyonse.