biology essay 2019 kcse

• 2024 LANJET Pre-Mock Exam
• 2024 End Term 1 Exams: Free Marking Schemes and Questions
• 2024 Maranda High Pre-Mock Exams & Marking Schemes Available Now!
• Unleash Your Potential: Download FREE Kabarak High KCSE Trial Exams 2024
• Free Access! 2024 Matete Sub-County Exams with Marking Schemes

FREE KCSE PAST PAPERS

KCSE PAST PAPERS

2019 KCSE Past Papers

Access 2019 kcse marking scheme.

On this post you will get free 2019 kcse exam papers. Click on the links below to download the papers in pdf format:

2019 KCSE Biology 1

2019 KCSE Biology 2

2019 KCSE Biology 3

2019 KCSE Business Studies Paper 1

2019 KCSE Business Studies Paper 2

2019 KCSE Chemistry Paper 1

2019 KCSE Chemistry Paper 2

2019 KCSE Chemistry Paper 3 2019 KCSE Computer Studies Paper 1

2019 KCSE Computer Studies Paper 2

2019 KCSE CRE Paper 1

2019 KCSE CRE Paper 2

2019 KCSE English Paper 1

2019 KCSE English Paper 2

2019 KCSE English Paper 3

2019 KCSE Geography Paper 1

2019 KCSE Geography Paper 2

2019 KCSE History & Government Paper 1

2019 KCSE History & Government Paper 2

2019 KCSE Kiswahili 1

2019 KCSE Kiswahili 2

2019 KCSE Kiswahili 3

2019 KCSE Maths Paper 1

2019 KCSE Maths Paper 2

2019 KCSE Physics Paper 1

2019 KCSE Physics Paper 2

2019 KCSE Physics Paper 3

2019 KCSE Agriculture Paper 1

2019 KCSE Agriculture Paper 2

The marking scheme of the above papers has not been released officially. We will be posting information on the marking scheme soon

2019 KCSE Analysis

Top 10 schools in 2019 kcse -schools with highest number of a's, grade   2019 total    2018 kcse total.

A                        627                                315

A-                      5796                                3418

C+ and above 125,746

Total Males 51% Total Females 49%

17 Counties had more females than males.

16 subjects had an improvement

11 subjects had a drop

Subjects that improved significantly include: English, Kiswahili, CRE, Home Science ,Art and Design and Sign Language

Most Improved Candidates

Cancelled results.

Results of 1309 (2019 KCSE) candidates were cancelled compared to 4915 (2018 KCSE).

Sample questions in HTML format

2019 kcse computer studies paper 1.

Answer all the questions in this section in the spaces provided.

1. State the hardware technological differences between the second generation and the third generation computers. (2 marks)

2. State two ways of ensuring proper ventilation in a computer room. (2 marks)

3. Convert the decimal number 20.373 to its binary number system equivalent. (3 marks)

4. Peter has installed internet in his home computer in order to use it for browsing. State three ways in which he would prevent viruses from infecting the computer. (3 marks)

5. State three ways of transforming a picture embedded in a Desktop Publishing programme in order to fit in a designated space on a document. (3 marks)

6. Differentiate between a line printer and a page printer as used in computers. (2 marks)

7. Describe virtual reality as used in computers. (2 marks)

8. State the function of each of the following features of an email software: (a) Inbox (1 mark)

(b) Draft (1 mark)

9 (a) Explain the term toggle key as used in computer keyboard.  (2 marks)

(b) List examples of toggle keys on a computer keyboard. (2 marks)

10. State the type of error that would occur in data processing for each of the following cases:

(a) Entering the number 315 instead of 3 51. ( 1 mark)

(b) Entering the text "K wys" instead of "Keys". (1 mark)

11. State four factors to consider when selecting an input device for use in a computer room. (4 marks)

12. State three functions of Un-interruptible Power Supply (UPS). (3 marks)

13. Distinguish between a page break and a column break as used in a word processor. (3 marks)

14. State three factors to consider when selecting an operating system to instal in a computer. (3 marks)

15. Differentiate between analogue data and digital data as used in computers.  ( 2 marks)

1. Form 1 Class Teachers of Mwango Secondary School intend to use a database to manage students performance in three examinations: opener, mid term and end term examinations.

(a) Open a database program and create a database named analysis. (1 mark)

(b)   (i) Create three tables named Class, StudDetails and StudMarks in the database file

created in (a) using the following details:

Class Table

StudDetails Table

  StudMarks Table

(i) Create the relationships between the (2 marks)

(ii) Create a form for the Class table and add a subform for the StudDetails table using the format in figure 1. Save the form as (4½ marks)

ClassID                      ClassName           Teacher

(iv) Enter the following data into their respective tables in the database. (12.5 marks)

StudMarks Table

( c) Create a query to display the fields: (i) AdNo, StudName, ClassID, Opener, MidTerm and EndTerm for all students in Form One East. Save the query as FlE. (4.5 marks)

(ii) AdNo, StudName, ClassID, Opener, MidTerm and EndTerm and a calculated field named meanscore to display the average in the three examinations.  Save the query as overall.  (6 marks)

(d) Create a report to display details of each student as it appears in Figure 2.  (2.5 marks)

(e) Print out each of the following: (3 marks)

(i) the three tables (ii) the two queries (iii) report for the first two students

2. The Chief Printer of Zenith Printers Company would like to have business cards. As a Desktop

Publishing (DTP) expert, you have been tasked to design the card for the officer.

(a) (i) Open a Desktop Publishing program and set the page layout as follows:

• Paper size: 8.5 cm width by 5.5 cm height    (5 marks) • Layout type: multiple pages per sheet • Target paper size: A4 • Orientation: Portrait • Margin: 0.75cm all round

(ii) Save the publication as business card. (1 mark)

(b) Design the card as it appears in Figure 3 ensuring that the card covers all the space in the page. (42 marks)

( c) Print out 10 copies of the card on a single A4 page. (2 marks)

More KCSE Papers

• End Term 3 Alliance 2019 Form 1,Form 2 & Form 3 Exams
• 2019 KCSE Best Schools

You May Also Like

Riara springs girls 2019 form 4 exams, 2020 mock booklets, kassu 2023 free questions and answers, 22 thoughts on “ 2019 kcse past papers ”.

I requested for IRE past papers

2019 KCSE IRE papers were not available on this package but they will be availed soon

Can I find for power mechanics pp1 and 2 ?

Ok thank you alot

I requested for mocks papers

Hello Lydia,

Please click on the link written KCSE mock papers to download

Can I found mathematics , biology, chemistry and English past papers

Yes, plenty, check the menus on the home page of this website for guide

Great initiative! But moderate the subscription fee to reach more financially biased population. Also involve commission on bulk purchase compared to handfuls…eg marking schemes for all KCSE 2019 for like (8) subjects … Otherwise it’s a good work. I just don’t know if the 20/- per paper includes schemes for all papers like Chem pp1, pp2, & pp3, or it’s 20/- per pp?

Hello Tyrus,

Thanks for your feedback. The requested has been done. Please refer: https://www.freekcsepastpapers.com/kcse-past-papers/ for more information.

THANKS FOR MAKING GREAT ACHIEVEMENTS TO OUR FOCUS STUDENTS

KCSE Physics paper 1 is missing page 4-5 kindly insert them and thank you for the good work.

Noted with thanks

Hello when will you fill in the missing pages, I am really eager to get them.Thank you.

2019 Kcse physics pp1 is also missing page 15.

pliz I like reading from this site

Art and Design Please

THESE KEEPS OUR CHILDREN BZ AT HOME

KCSE paper physics

Check: https://www.freekcsepastpapers.com/kcse-past-papers-physics/

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Notify me of follow-up comments by email.

Notify me of new posts by email.

Education News Hub

Biology KCSE Past Papers and all marking schemes free downloads

In case you are looking for free KCSE Biology Past Papers and their marking schemes, then you can download them here free. Simply click on the respective links below to download the free Biology KCSE past papers and their marking schemes per year.

FREE BIOLOGY KCSE 2008 PAST PAPERS AND ANSWERS

• 2008-KCSE-BIOLOGY-PAPER-1-MS

Click here to download free

• 2008-KCSE-BIOLOGY-PAPER-1
• 2008-KCSE-BIOLOGY-PAPER-3-MS

FREE BIOLOGY KCSE 2009 PAST PAPERS AND ANSWERS

• 2009KCSE-BIOLOGY-QUESTIONS

FREE BIOLOGY KCSE 2010 PAST PAPERS AND ANSWERS

• 2010-2011-BIOLOGY-ANSWERS
• 2010-2011-BIOLOGY-QUESTIONS

FREE BIOLOGY KCSE 2012 PAST PAPERS AND ANSWERS

• 2012 KCSE BIOLOGY Marking scheme
• 2012-KCSE-BIOLOGY-PAPER-1
• 2012-KCSE-BIOLOGY-PAPER-2
• 2012-KCSE-BIOLOGY-PRACTICAL-PAPER-3

Click here for a free download

FREE BIOLOGY KCSE 2013 PAST PAPERS AND ANSWERS

• 2013-KCSE-BIOLOGY-MS
• 2013-KCSE-BIOLOGY-QUESTIONS

FREE BIOLOGY KCSE 2014 PAST PAPERS AND ANSWERS

• 2014-KCSE-BIOLOGY-MS
• 2014-KCSE-BIOLOGY-QS-PAPERS

Biology Free notes and Exams for Form one to Four

Biology Form one to four exams, notes and revision materials

Biology notes form 1-4; Free KCSE downloads

Free Biology notes, revision questions, KCSE past Papers, Exams, Marking Schemes, Topical revision materials, Syllabus and Many more

• Free KCSE Past Papers and Form 4 Revision Materials

FREE BIOLOGY KCSE 2015 PAST PAPERS AND ANSWERS

• 2015-KCSE-BIOLOGY-PP1
• 2015-KCSE-BIOLOGY-PP2
• 2015-KCSE-BIOLOGY-PP3

FREE BIOLOGY KCSE 2016 PAST PAPERS AND ANSWERS

• 2016-KCSE-BIOLOGY-PP1
• 2016-KCSE-BIOLOGY-PP2
• 2016-KCSE-BIOLOGY-PP3

2016-Marking Schemes-ALL-SUBJECTS

Click here for a free download.

FREE BIOLOGY KCSE 2017 PAST PAPERS AND ANSWERS

• 2017 KCSE BIO PP1 MS
• 2017 KCSE BIO PP2 MS
• 2017 KCSE BIOLOGY PP1
• 2017 KCSE Biology report
• 2017 KCSE_BIOLOGY PP2
• 2017-KCSE-BIOLOGY-PP2-MARKING-SCHEME
• 2017-KCSE-BIOLOGY-PP3-ms

FREE BIOLOGY KCSE 2018 PAST PAPERS AND ANSWERS

• Biology 2018 231 P3 MS –
• 2018 Biology Paper 2 Marking Scheme
• 2018 KCSE Biology Paper 3 Marking Scheme
• 2018 KCSE BIOLOGY PP2
• 2018 KCSE BIOLOGY PP3
• 2018 KSCE biology Paper One Marking Scheme free

FREE BIOLOGY KCSE 2019 PAST PAPERS AND ANSWERS

• 2019 KCSE Biology Paper One Marking Scheme
• 2019 KCSE BIOLOGY PAPER ONE QUESTION PAPER
• 2019 KCSE BIOLOGY PAPER 2 MARKING SCHEME
• 2019 KCSE BIOLOGY PAPER 2 QUESTION PAPER
• 2019 KCSE BIOLOGY PAPER 3 QUESTION PAPER

Didn’t get what your were looking for? Worry not. Click here to access all primary and secondary resources at no cost; Free notes, exams, schemes of work, lesson plans and revision materials.

Also read..

BIOLOGY FORM ONE SUMMARIZED NOTES

BIOLOGY FORM FOUR SUMMARIZED NOTES

BIOLOGY FORM TWO SUMMARIZED NOTES

BIOLOGY FORM ONE NOTES FREE

BIOLOGY FORM THREE SUMMARIZED NOTES

Biology notes (Updated form one to four free notes)

Biology Simplified Notes Form 1 to 4 Free

BIOLOGY KCSE MARKING AND SETTING TIPS IN LINE WITH EMERGING TRENDS

Biology topical questions and answers

Biology free lesson plans for all topics (Form one to four)

CBC Senior School Subjects (Grade 10, 11, 12)

CRE free lesson plans for all topics (Form one to four)

History and Government free lesson plans for all topics (Form one to four)

Free Secondary School Exams and Marking schemes (Form 1 to 4)

Syllabus For All Secondary Schools Per Subjects (Latest Syllabus)

English free lesson plans for all topics (Form one to four)

Free Physics notes, revision questions, KCSE past Papers, Exams, Marking Schemes, Topical revision materials, Syllabus and Many more

FORM 4 EXAMINATIONS AND MARKING SCHEMES: ALL SUBJECTS FOR KCSE CANDIDATES- OVER 1,000 PAPERS

Form 4 Term 1-3 Free Exams and marking schemes; All subjects downloads

FORM 3 ALL SUBJECTS EXAMS, ASSIGNMENTS: FREE TERM 1-3 EXAMS & ANSWERS

Updated Secondary School Notes form one to four Free Downloads (All subjects Comprehensive Notes)

Physics free lesson plans for all topics (Form one to four)

8 thoughts on “Biology KCSE Past Papers and all marking schemes free downloads”

Resourceful

EXCELLENT WORK.WE REALLY APPRECIATE

Very resourceful

i am a campus student, and i just learnt about this site and i must say am impressed sitting for my having my exams this march and good enough it has lots of information i needed.

Hi Bryan, Kodi doesn’t seem to be working on Xbox at the moment. Unfortunately the only option is to wait for a patch. Ian

Very awesome, and interesting platform of learning indeed it helps to achieve much in academic affairs I real like this

Very resourceful Good work keep it up 👍

Regards, Excellent stuff!|

Leave a Comment Cancel reply

Save my name, email, and website in this browser for the next time I comment.

• google_plus

2019 K.C.S.E KNEC PAST PAPERS

  2019 k.c.s.e  knec past papers  .

Download all the 2019 K.C.S.E Past Papers by Kenya National Examination Council.  The list includes all the 2019 KCSE Question Papers with their Marking Schemes.

Download free Kenya Certificate of Secondary Education  2019 KCSE Examinations Past Papers  with Questions and Answers for all subjects.

The list includes English, Kiswahili, Mathematics, Biology, Chemistry, Physics, History, Christian Religious Education CRE, Geography, IRE, Agriculture, Business Studies, Computer Studies, Home Science, Woodwork, Art and Design, music, etc.

Click on the links below to Download the 2019 KCSE Papers with Marking Schemes

Use the links below. Click on  a link to a specific material.

AGRICULTURE P1 KCSE 2019

Agriculture p2 kcse 2019, art and design p1 kcse 2019, art and design p2 kcse 2019, biology p1 kcse 2019, biology p2 kcse 2019, biology p2 ms kcse 2019, biology p3 confidential kcse 2019, biology pp3 practicals kcse 2019, business p1 kcse 2019, business p1 ms kcse 2019, business p2 ms kcse 2019, chemistry p1 kcse 2019, chemistry p2 kcse 2019, chemistry p3 kcse 2019, chemistyr p1 ms kcse 2019, computer p1 kcse 2019, computer p2 kcse 2019, cre p1 kcse 2019, cre p1 ms kcse 2019, cre p2 kcse 2019, english p1 kcse 2019, english p2 kcse 2019, english p3 kcse 2019, french p1 kcse 2019, french p2 kcse 2019, geography p1 kcse 2019, geography p1 ms kcse 2019, geography p2 kcse 2019, geography p2 ms kcse 2019, history p1 kcse 2019, history p1 ms kcse 2019, history p2 kcse 2019, history p2 ms kcse 2019, kiswahili p2 kcse 2019, kiswahili p1 kcse 2019, kiswahili p3 kcse 2019, kiswahili p3 ms kcse 2019, mathematics p1 kcse 2019, mathematics p1 ms kcse 2019, mathematics p2 kcse 2019, mathematics p2 ms kcse 2019, physics p1 kcse 2019, physics p2 kcse 2019, physics p2 ms kcse 2019, physics p3 conf kcse 2019, physics p3 kcse 2019, download additional kcse past examinations papers with marking schemes, 2019 kcse past papers and marking schemes, 2018 kcse past papers and marking schemes, 2017 kcse past papers and marking schemes, 2016 kcse past papers and marking schemes, 2015 kcse past papers and marking schemes, 2014 kcse past papers and marking schemes, 2013 kcse past papers and marking schemes, 2012 kcse past papers and marking schemes, 2011 kcse past papers and marking schemes, 2010 kcse past papers and marking schemes, 2008 kcse past papers and marking schemes, 1996 – 2009 k.c.s.e past papers and marking schemes, read 2019 kcse knec reports below.

• 2019 KCSE BIOLOGY (231) KNEC REPORT
• 2019 KCSE AGRICULTURE (443) KNEC REPORT  
• 2019 KCSE BUSINESS STUDIES (565) KNEC REPORT
• 2019 KCSE CHEMISTRY (233) KNEC REPORT  
• 2019 KCSE CHRISTIAN RELIGIOUS EDUCATION CRE (313) KNEC REPORT  
• 2019 KCSE ENGLISH (101) KNEC REPORT
• 2019 KCSE HISTORY AND GOVERNMENT (311) KNEC REPORT
• 2019 KCSE KISWAHILI (102) KNEC REPORT  

Links to Download more free Education Materials 

Form 1-4 lesson notes, form 1-4 termly examinations papers and marking schemes, free online video lessons, download schemes of work, form 1-4 topic by topic questions and answers (all subjects), form 1-4 powerpoint slides notes, download powerpoint slides notes, k.c.s.e revision materials, form 1-4 knec syllabus, download form 1-4 lesson plans, 1996 – 2019 k.c.s.e past papers, mock k.c.s.e past examinations papers and marking schemes, university resources, primary school (grade 4 – 8) resources, pre-primary school materials.

Updated on 6/12/2023.

Get Informed About Kenyan Life

2019 kcse biology paper 2 past paper-free kcse past papers with answers., 2019 kcse biology paper 2 past paper.

Answer all the questions in the spaces provided.

1. In an experiment to investigate the effect of Sodium chloride on the growth rate in a spinach seedling. seeds were treated with different concentrations of sodium chloride. The results are as recorded in the table below.

(a) From the results in the table above, explain the effect of increasing the concentration of sodium chloride. (3 marks)

(b) Apart from a ruler, state two other equipment one would need to determine the rate of growth in the roots. (2 marks)

(c) With a reason, state one other part of the seedling the students would focus on to determine the effect of sodium chloride on growth. (2 marks)

(d) State the likely effect on the seedling of increasing the seedling of increasing the conccntration of sodium chloride to 2.20 mol/I . (1 mark)

2. The table below shows results of blood cell counts per mm° of blood from a sample of people living at different altitudes.

(a) Explain the relationship between:

(i) Red blood cells count and the altitude;(3 mark)

(ii) White blood cells count and the altitude.(3 mark)

(b) Explain why chances of nose-bleeding increase with altitude in humans. (2 marks)

3. (a) State one importance of irritability to living organism. ( 1 mark)

(b) ln an experiment, students treated seedlings as illustrated below.

(i) Account for the observations made in seedling 1 (3 marks)

(ii) Explain the similarity in the end results made in seedlings II and II (2 marks)

(iii) State the likely treatment that would make seedlings II and III respond like seedling I. (2 marks)

4. In cats, the gene for fur colour is sex-linked. Letter G represents the gene for ginger fur colour while letter B represents the gene for black fur colour in a given cot species. These genes are codominant.

Heterozygous females have ginger and black patches of fur rind their phenotype is described as tortoise-shell.

(a) With reference to the information given above, what is meant by the term codominance? (1 mark)

(b) Explain why male cats with a tortoise-shell phenotype do not usually occur. (2 marks)

(c) A tortoise-shell female was crossed with a black male. Determine the genotypes and phenotypes of the offspring. (5 marks)

5. A person accidentally touches a hot pan and responds as illustrated in the diagram below.

(a) Explain how the response illustrated above occurs. (6 marks)

(b) Explain how auxins are utilised as selective weed killers in agriculture. (2 marks)

SECTION B (40 Marks)

Answer question 6 (compulsory) and either 7 or 8

6. The table below shows the rate of product formation for two enzymes, H and J over a range of pH values.

(a) On the same axis, plot graphs of the rate of product formation against pH. (8 marks)

(b) Account for the rate of product formation for enzyme H between:

(i) pH 1.0 and 3.0 (3 marks)

(ii) pH 3.0 and 7.0. (3 marks)

(c) From the graph, determine:

(i) The pH value at which the rate of product formation of the two enzymes was the same (l mark)

(ii) The value of the rate of product formation for enzymes H and I at the pH value stated in (G)(i) above (1 mark)

(iii) The optimum pH value for enzyme J (l mark)

(d) State one variable that may lead to the change in the optimum rate of product-formation of the two enzymes. (l mark)

(e) Suggest with a reason, the likely part of the human alimentary canal where enzyme H would be found. (2 marks)

7.Giving examples,describe the following interactions among organism: (20 marks)

8. Explain the effects of increased physical activity on the following organ systems: (20 marks)

(C) Kidneys

2019 KCSE Biology Paper 2 Past Paper-Marking Scheme/Answers

Increased Sodium chloride concentration/having more sodium and chloride ions solutes decreases osmotic potential/makes water potential more negative outside the seed/seedling in the surrounding solution/the surrounding solution to be hypertonic to the cell sap in the seedling/ seed cells; seeds take in less water by osmosis/are dehydrated/lose water molecules to the surrounding solution; reducing the (growth) enzyme activity, hence reduced growth rate; OWTTE

(b) Apart from a ruler, state two other equipment one would need to determine the rate of growth in the roots. (2 marks) Thread; Marker pen; Dye

(Rate of growth/increase in length of) the shoot tip/apex; It is a region of (active) cell division/growth;

(d) State the likely effect on the seedling of increasing the seedling of increasing the concentration of sodium chloride to 2.20 mol/I . (1 mark)

The seedling will be dehydrated, hence wither/die

(i) The number of red blood cells count increase with the increase in altitude; to increase the oxygen carrying capacity (by the hemoglobin molecules in blood); since oxygen concentration is lower at higher altitudes

White blood cells serve to protect the body against harmful micro-organisms/pathogens; the quantities of pathogens or vulnerability of the body to microbial attack is not dependent on the altitude (to be countered by the white blood cells); hence the number of white blood cells’ count is constant at whatever

Atmospheric pressure decreases with the increase in altitude; the imbalance between the (outer) atmospheric pressure at high altitude and the internal blood pressure (generated by the heart) results in one nose bleeding at higher altitudes/internal blood pressure is higher than the (outer) atmospheric pressure .

3. (a) State one importance of irritability to living organism. ( 1 mark) Enables living organisms to avoid dangerous/harmful/harsh climatic/environmental conditions;Enable living organisms obtain/access favourable environmental conditions (light, water, oxygen); any one

(i) Positive phototropism/tip bends towards light light causes migration of auxins (produced at the tip); to darker side of the shoot resulting in faster division of cells/elongation on the darker/ opposite side of the shoot, hence bending towards light;

(ii) Both seedlings remain upright; seedling II does not have the tip while in III the tip has been covered by an opaque material preventing light from causing unequal distribution of auxins;

Fitting an agar block treated with auxins at the decapitated end of seedling II; removing the opaque material covering the tip of seedling III Replacing the opaque cap with a transparent one;

4. In cats, the gene for fur colour is sex-linked. Letter G represents the gene for ginger fur colour while letter B represents the gene for black fur colour in a given cot species.

These genes are codominant.

Both alleles are expressed/shown equally in the phenotype (of the offspring) /non suppresses the other/ gene for ginger and black fur colour express themselves equally in the phenotype of the offspring.

The gene for coat colour is sex-linked; contained in the X-chromosome; males have only (inherit) one X-chromosome (from females/mothers)/Y-chromosome does not carry genes;

The stimulus/heat/pain is detected by temperature/pain receptors (in the skin/dermis); impulses transmitted along sensory neurone to the Central Nervous System/spinal cord; (chemical) transmission across synapses; to relay neurone; across a synapse to motor neurone/across another synapse /via motor neurone; to muscles/effectors via motor neurone; muscles/effectors contract, (hand moves away); This is known as a reflex action;

Selective weed killers contain auxins which are absorbed by the weeds (than desired/beneficial/plants); making the weeds to grow abnormally faster/die out (ahead of the desired plants);

Rate of product formation increases with the increase in pH up to the optimum/then decreases; pH 2.0 is the optimum pH value for the activity of enzyme ii; between pH 1 and 2, the enzyme molecules are activated;

Rate of product formation (sharply) decreases with the increase in pH; enzyme IN is not favoured by the increase in pH, hence is denatured; no product forms above/beyond pH 4.0 to 7.0 (all enzyme molecules will have been denatured);

15.0 mg/hour;

(d) State one variable that may lead to the change in the optimum rate of product-formation of the two enzymes. (l mark) Temperature (increasing beyond 40°C or extremely lowering it); (Varying) substrate concentration; Enzyme concentration;

(e) Suggest with a reason, the likely part of the human alimentary canal where enzyme H would be found. (2 marks) Stomach; Acidic medium/low pH;

Predator-prey relationship

A predator is an animal that hunts/kills another/other animals (prey) for food; example, a dog and a hare; preys devise survival mechanisms in their habitats not to be eaten/killed; to survive and reproduce/propagate their lineage; to this end, they run faster (strong hind leg muscles); camouflage with environments; mimic the predators; or strong sense of smell to detect the predator; some emit chemicals/smell that turn away from the predators; while others, like porcupines, use quills/spines/ spikes to fight off predators; on the other hand, predators also evolve/ device means to be able to survive in such an ecosystem, for instance, running faster/camouflaging with the environment/mimicking preys/ sharp eyesight; some produce venom/poison; sharp/strong/long claws;

Is a close, (long-term) association between two organisms of different species where the two mutually benefit from each other; for example, the bacteria in the rumen/gut/colon of herbivores; which help the herbivores digest cellulose; as they are sheltered by the herbivores; the bacteria found in the human digestive system/gut; are also sheltered by humans as they ensure microbial balance; the nitrogen-fixing bacteria on the root nodules of leguminous plants; benefit from the shelter offered by the plants; as they facilitate conversion of free atmospheric nitrogen into forms that can be readily absorbed by the plants;

Is a kind of(inter-specific) relationship/association where one member/ organism, the parasite, benefits while the other, the host is harmed/ loses; (also called antagonistic/antipathetic symbiosis) for example, a tick (parasite); sucking blood from a cow (host), making the cow to be anaemic/skin destroyed/malnourished; parasites can be external/ecto- parasite; or internal/endo-parasite; endo-parasites,for instance, liver fluke, suck blood/nutrients from the host and can cause death/bodily harm on the internal organs of the host, including blocking blood vessels;

Increased physical activity results in increased heart beat/rate/cardiac frequency/increased blood pressure; pumping more blood to the muscles/peripheral blood vessels at a faster rate; supplying oxygen; nutrients; for continued oxidation/respiration; to yield energy needed to sustain the (vigorous) contraction/relaxation of muscles (during the physical activity); carbon (IV) oxide/lactic acids/other nitrogenous/ metabolic wastes produced during the process are also eliminated/ transported to the relevant excretory organs for elimination; the wastes, if left to accumulate, can also poison cells/cause muscle crump/ fatigue/pain;

The panting/increased breathing rate (during the physical activity) influences the lung volume/lungs expand/increase in volume, to take in more amount of air/oxygen retained (for the activity) or expelled (during the activity); they expand to take in more air/oxygen (into the body) and deflate to expel more carbon (IV); more oxygen is taken in (during exercise) to sustain the process of muscle respiration/to produce the required energy (for the constant muscle contraction and relaxation);

Kidneys also maintain the blood plasma pH; and osmotic balance; by eliminating excess hydrogen ions(H“) that accumulate for instance, through the production of lactic acid/carbon (IV) oxide during exercise; to maintain the osmotic balance, the kidneys conserve sodium ions and reabsorb water (in the kidney tubules); leading to reduction in the volume of urine produced; during exercises, the kidneys tend to filter out more urea, releasing more in the urine;

Due to the increased muscle activity during physical exercises, one sweats (more); eliminating nitrogenous wastes/excess water (through the skin)/sweat pores; cooling the body; after water in the sweat evaporates; the increased internal body temperature also leads to the dilation of superficial blood vessels (vaso-dilation)/blood flowing to the skin; leading to loss of excess heat (to the atmosphere) by radiation/ convection; the hair on the skin surface also lie flat to allow for loss of heat (to the environment) by radiation/convection;

Share this:

Copyright © 2024 | Powered By Kenyanlife.com

KCSE Past Papers 2019 Biology Paper 3  (101/3)

Biology paper 3 nov. 2019 - 1 ¾  hours, click here - free kcse past papers » knec past exams » free downloads » kcse papers & marking schemes.

• NGOs Grants
• Current Scholarships
• Jobs in Africa
• Link to Us!
• Site Search
• What is New?
• Volunteer in Africa
• Volunteer in Kenya
• Medical Electives
• Submit Article
• Internships
• Scholarships Grants
• Undergraduate Scholarships
• Call for Proposals
• Study Abroad
• KCSE Past Papers
• Research Grants
• Entrepreneur Grants
• Journalist Grants

Scholarship 2024/25

• Form 1 Mathematics Notes
• Form 2 Mathematics Notes
• Form 3 Mathematics Notes
• Form 4 Mathematics Notes
• Form 1 Mathematics Topical Questions and Answers
• Form 2 Mathematics Topical Questions and Answers
• Form 3 Mathematics Topical Questions and Answers
• Form 4 Mathematics Topical Questions and Answers
• Form 1 Functional Writing Notes
• Form 2 Functional Writing Notes
• Form 3 Functional Writing Notes
• Form 4 Functional Writing Notes
• Poetry Notes
• Grammar Notes
• Oral Literature Notes
• Oral Skills Notes
• Guide to Blossoms of the Savannah Summarized Notes - Easy Elimu
• A Doll's House
• The Pearl Study Guide
• Memories We Lost and Other Stories Study Guide
• Inheritance Study Guide
• A Silent song and Other Stories Guide
• Fathers of Nations Guide
• An Artist of the Floating World Guide
• The Samaritan Guide
• Sarufi na Matumizi ya Lugha
• Isimu Jamii Notes
• Fasihi Notes
• Ushairi Notes
• Mwongozo wa Kuandika Insha
• Tumbo Lililoshiba na Hadithi Nyingine
• Mwongozo wa Kigogo
• Mwongozo wa Chozi La Heri - Chozi la Heri Notes PDF
• Mwongozo wa Bembea ya Maisha - Bembea ya Maisha Notes PDF
• Mwongozo wa Nguu za Jadi
• Mwongozo wa Mapambazuko ya Machweo na Hadithi Nyingine
• Biology Form 1 Notes
• Biology Form 2 Notes
• Biology Form 3 Notes
• Biology Form 4 Notes
• Biology Essays
• Form 1 Biology Topical Revision Questions and Answers
• Form 2 Biology Topical Revision Questions and Answers
• Form 3 Biology Topical Revision Questions and Answers
• Form 4 Biology Topical Revision Questions and Answers
• Form 1 Chemistry Notes
• Form 2 Chemistry Notes
• Form 3 Chemistry Notes
• Form 4 Chemistry Notes
• All Chemistry Practicals Notes for KCSE and MOCKS
• Form 1 Chemistry Topical Revision Questions and Answers
• Form 2 Chemistry Topical Revision Questions and Answers
• Form 3 Chemistry Topical Revision Questions and Answers
• Form 4 Chemistry Topical Revision Questions and Answers
• IRE Form 1 Notes
• IRE Form 2 Notes
• IRE Form 3 Notes
• IRE Form 4 Notes
• Physics Form 1 Notes
• Physics Form 2 Notes
• Physics Form 3 Notes
• Physics Form 4 Notes
• CRE Form 1 Notes
• CRE Form 2 Notes
• CRE Form 3 Notes
• CRE Form 4 Notes
• Geography Form 1 Notes
• Geography Form 2 Notes
• Geography Form 3 Notes
• Geography Form 4 Notes
• History Form 1 Notes
• History Form 2 Notes
• History Form 3 Notes
• History Form 4 Notes
• Business Studies Form 1 Notes
• Business Studies Form 2 Notes
• Business Studies Form 3 Notes
• Business Studies Form 4 Notes
• Home Science Form 2 Notes
• Home Science Form 3 Notes
• Home Science Form 4 Notes
• Home Science Form 1 Notes
• Agriculture Form 1 Notes
• Agriculture Form 2 Notes
• Agriculture Form 3 Notes
• Agriculture Form 4 Notes
• Agriculture KCSE 2019 Project
• Computer Studies Form 1 Notes
• Computer Studies Form 2 Notes
• Computer Studies Form 3 Notes
• Computer Studies Form 4 Notes
• KCSE 2017 Reports
• 2018 Pre-Mocks
• 2019 Pre-Mocks
• 2022 Pre Mocks
• 2021/2022 Pre-Mock Past Papers
• 2023 Pre Mocks
• 2017 Mock Past Papers
• 2019 Mock Past Papers
• 2020 Mock Past Papers
• Mock Exam Papers 2021/2022 - Easy Elimu
• Mock Exam 2022 Questions and Answers
• Alliance Boys High School
• Maranda High School
• Form 1 Past Papers
• Form 2 Past Papers
• Form 3 Past Papers
• Form 4 Past Papers
• 2019 KCSE Prediction Papers
• 2020 KCSE Prediction Papers
• 2021 KCSE Prediction Papers
• 2022 KCSE Prediction Questions and Answers - EasyElimu
• KCSE Prediction 2023
• 2020 Post Mock Past Papers
• 2021/2022 Post Mocks
• 2023 Post Mocks
• Play Group: Activities, Homework and Syllabus
• 2023 PP1 Exams
• 2023 PP2 Exams
• Grade 1 Notes
• 2023 Grade 1 Exams
• Grade 2 Notes
• 2023 Grade 2 Exams
• Grade 3 Notes
• 2023 Grade 3 Exams
• Grade 4 Notes
• 2023 Grade 4 Exams
• Grade 5 Notes
• 2023 Grade 5 Exams
• Grade 6 Notes
• KPSEA Exams
• 2023 Grade 6 Exams
• Class 6 : Notes, Revision Papers and Syllabus
• Class 7 : Notes, Revision Papers and Syllabus
• Class 8 Notes
• 2023 Class 8 Exams
• 2023 Kcpe Prediction
• Grade 7 Notes
• 2023 Grade 7 Exams
• The New EasyElimu Website
• Form 4 End Term 1 Exams
• Form 3 Exams 2024
• Form 2 End Term 1 Exams
• Form 1 End Term 1 Exams
• All Kiswahili setbook guides
• All English setbook guides
• Form 1 - 4 High School Notes

Biology Paper 1 Questions and Answers - KCSE 2020 past papers

« Previous Topic Biology Paper 3 Questions and Answers - KCSE 2020 past papers

Next Topic » Physics Paper 1 Question and Answers - KCSE 2020 Past Papers

Instructions to candidates

• Answer  all  the questions.
• Candidates should answer the questions in English.

Answer  all  the questions in the spaces provided.

• Name the taxonomic grouping that contains individuals with most similarities.   (1 mark)
• budding in yeast; (1 mark) 
• enlargement of the eye pupil in dim light.  (1 mark)
• Explain why there is no grass in most dense forests. (2 marks)
• State  one  structural difference between a cell wall and a cell membrane. (1 mark)

• Name the Kingdom to which the organism belongs. (1 mark)
• State the mode of nutrition for the organism. (1 mark)
• Name the part labelled E. (1 mark)
• State  two  functions of the part labelled E. (2 marks)
• State the importance of a well-developed blood capillary network in the alveoli. (1 mark)
• Name the genetic disorder in humans that is characterised by inability of blood to clot. (I mark)

• Account for the shape of the sketch made in (a) above. (2 marks)
• Explain why plants have lower respiratory rates compared to animals. (l mark)
• State  two  situations in plants when the rate of respiration rises more than normal. (2 marks)
• Explain why most plants growing in water-logged areas die before attaining maturity. (3 marks)

• the meaning of the term imbibition (1 mark)
• why the dry mass of the endosperm decreases while that of the embryo increases. (2 marks)
• State  two  characteristic features used to classify members of Class Coniferales. (2 marks) 

• Name the type of growth curve shown. (1 mark)
• Name the Phylum where members show the type of growth curve illustrated. (1 mark)
• State  two  limitations of using fossil records in retracing evolutionary history of living organisms.(2 marks)
• Describe cell biology as an evidence of organic evolution. (3 marks)

• Name the process that takes place around the 14th day. (1 mark))
• Name  two  hormones produced at the follicular phase. (2 marks)
• Under which two conditions would the cycle be interrupted? (2 marks)
• State  two  reasons why blood reaching the glomerulus is always under high pressure. (2 marks)
• the hormone that was deficient in the patient: (1 mark)
• the gland that produces the hormone named in (a) above; (1 mark) 
• the disease the individual was likely to be suffering from. (1 mark) 

• Name enzymes S and T. S (1 mark) T (1 mark)
• Name the part of the alimentary canal where enzyme T is likely to be found. (1 mark)
• Explain your answer in b(i) above. (2 marks)
• Explain the biological significance of completing a dose of antibiotics. (3 marks)
• State  two  reasons why females with Turners' Syndrome are infertile. (2 marks)) 
• Define the term "field of view" as used in microscopy. (1 mark)
• State  two  functions of the body tube of a light microscope. (2 marks)
• Give a reason why it is  not  advisable to use water in cleaning a microscope. (1 mark) 
• Explain the role of blood capillaries in thermoregulation. (2 marks)

• the hormone K (1 mark)
• gland L that produces ecdysone hormone (1 mark)
• State the role of ecdysone hormone in the growth and development of insects. (1 mark)
• Name process M (1 mark)
• Account for the rapid increase in size of organisms immediately after moulting. (2 marks)
• Explain why the leaf of a sisal plant has a thick and shiny cuticle. (2 marks)
• Explain why an individual with blood group AB can only donate blood to an individual with the same blood group. (2 marks)

• process N (1 mark)
• polysaccharide p (1 mark)
• State  two  conditions necessary for the formation of compound Q. (2 marks)
• State  two  environmental conditions necessary for process N to take place. (2 marks)

MARKING SCHEME

• (Asexual) reproduction; Rej sexual
• Irritability/ Response (to stimulus) /Sensitivity
• Form canopies/shadows/shade; which prevent light from reaching grass; grass die/fail to flourish due to their inability to photosynthesis; 
• Cell wall is (fully) permeable while cell membrane is semi-permeable. (cell wall has larger pores while cell membrane has smaller pores)
• Cell wall is (mainly) made up of cellulose (fibres) while cell membrane has a (double) protein layer sandwiching a lipid layer; Acc. lipoprotein
• Cell wall is rigid, tougher ( cannot burst) while cell membrane is weaker (bursts)
• Fungi; Acc. fungi
• Saprophytism/saprophytic/food on dead decaying (organic) matter; Rej. Saprophyte
• Hypha/Hyphae; Acc. mycelium Rhizoids
• Secretes digestive enzymes(for external digestion); 
• Anchors the organism/mushroom (firmly) onto the substrate. Acc. anchorage.
• Absorbs digested food materials/Absorbs water and mineral salts/ions.
• Increases the surface area for (efficient) exchange/transport of respiratory gases ( oxygen and carbon (IV) oxide)
• Haemophilia; Acc. Hemophilia

• The rate of diffusion increases with the increase in temperature; Increase in temperature increases the kinetic energy of the (diffusing) molecules (increasing the rate of diffusion).
• Plants are less active than animals, hence require lower amount of energy than animals.
• During germination (to generate energy required for the process.
• During rapid growth/cell division (at the tips of roots/shoots).
• During active uptake/transport of substances (through the roots).
• Waterlogging submerges the plant root system; Cutting off supply of oxygen to the roots/soil surrounding the roots.
• (Aerobic) respiration in the roots is hampered
• active uptake/transport of materials is affected (leading to the death of the affected plants).
• K- Ulna L- Radius
• (Rapid) absorption of water by (germinating) seed (through the micropyle/seed coat).
• During germination, stored food in the endosperm is broken down/hydrolyzed/oxidized; to provide nutrients for the growing embryo.
• Presence of cones
• Naked seeds, seeds not enclosed in fruits
• Xerophytic characteristics/needle-like leaves/ thick waxy cuticle/sunken stomata.
• Intermittent/staircase (growth curve)
• arthropoda; correctly spelt Acc. arthropoda/Athropoda/athropoda    Rej. Anthropoda/ anthropoda
• Missing links due to complete decomposition of some organisms.  Acc. some parts decomposing
• Distortion of parts during sedimentation.
• Destruction of fossils by geological activities (earthquakes/faulting/mass movement of earth surfaces/volcanicity) 
• Presence of similar cell organelles ( mitochondria, ribosomes,lysosomes);
• Similar biological chemicals(ATP/proteins/DNA); 
• Similar blood pigmentation in tissues of some groups of animals show they have a common phytogenetic origin.
• Follicle stimulating hormone Rej. FSH
• Oestrogen/Estrogen
• Luteinizing hormone  Rej. LH
• (Drastic) change in weather/environment.
• Pregnancy/Implantation/Conception   Rej. fertilisation
• Emotional instability (anger, stress, anxiety).
• Renal artery branches directly from (dorsal) aorta whose blood under pressure
• Afferent arteriole/supplying blood is broader than efferent taking out blood.
• Diabetes mellitus    Rej. Diabetes alone
• S - Pepesin; Acc.  Chymosin/Rennin  Rej. Renin T- Trypsin
• In the duodenum, the medium is alkaline/basic; favouring the optimal working of the enzyme (T) as illustrated
• To completely kill/contain the (targeted) pathogens; Since failure to take full dose accords the pathogens an opportunity to develop resistance to the drug; the pathogen mutates(overtime) giving rise to a new strain; finally the drug becomes ineffective.
• They lack ovaries
• Have small uterus
• Less number of chromosomes.
• A circular area seen (on the stage) when focusing/viewing through the eyepiece of a microscope.
• Holds the revolving nose piece/objective lenses in place
• Holds the ocular/eyepiece (lens) in place
• To avoid rusting
• To avoid interference with visibility of the lens.
• Constrict during cold/low temperatures; to conserve heat
• Dilate during hot/high temperature; to facilitate heat loss
• Juvenile (hormone)
• prothoracic (gland)
• Ecdysone (hormone) causes metamorphosis; or causes the larval stage (of an insect to change/metamorphosize into pupa and pupa into adult.
• Complete Metamorphosis
• During moulting (the tough/hard impermeable) exoskeleton is shed; allowing the (soft permeable) larvae to take in air/water leading to rapid growth (which in turn results to increase in size of the organism).
• (Sisal is a xerophyte) the thick cuticle enables it to conserve water; reduce water loss;
• It is shiny to reflect light,minimizing evaporation by radiation.
• The individuals blood has both antigen A and B; which will coagulate/agglutimate with antibodies a and b; found in individuals with blood groups A,B and O; OWTTE
• Photosynthesis
• Respiratory enzymes
• Absence/little oxygen
• Optimum temperature
• Water/Moisture
• Carbon (IV) oxide

Download Biology Paper 1 Questions and Answers - KCSE 2020 past papers .

Why download.

• ✔ To read offline at any time.
• ✔ To Print at your convenience
• ✔ Share Easily with Friends / Students

Related items

• Arabic Paper 1 Questions and Answers - KCSE 2021 Past Papers
• Music Paper 1 Questions and Answers - KCSE 2022 Past Papers
• Aviation Technology Paper 2 Questions and Answers - KCSE 2021 Past Papers
• Aviation Technology Paper 1 Questions and Answers - KCSE 2021 Past Papers
• Electricity Paper 2 Questions and Answers - KCSE 2021 Past Papers

access all the content at an affordable rate or Buy any individual paper or notes as a pdf via MPESA and get it sent to you via WhatsApp

What does our community say about us?

Join our community on:.

• KCSE Revision Questions
• Privacy Policy
• Mobile App Privacy Policy
• High Schools in Kenya
• Teacher Resources
• Questions and Answers
• Online Tuition and Classes in Kenya

Copyright © 2022 EasyElimu