ANSWER ALL THE QUESTION IN THE SPACES PROVIDED.
- You are provided with substance L.Carry out food tests on the substance using the reagents provided .Record your procedure , observations and conclusions in the table below.(9mks)
Food substance Procedure Observation Conclusions
Dichotomous Key.
-
- Animal with a flattened body….. …………………………………..go to 9.
- Animal without a flattened body……………………………………. go to 2.
-
- Animal with body in a shell ………………………………………….Mollusca.
- Animal with body in shell………………………………………….. go to 3.
-
- Animal with segmented body….. …………………………………….go to 4.
- Animal with body not segmented…………………………………….Nematoda.
-
- Animal with jointed appendages go to 6.
- Animal without jointed appendages to 5.
-
- Animal with long and cyndrical body…………………………………..annelida.
- Animal with short stout body………………………………………….. Trenada.
-
- Animal with antennae…………………………………………………...go to7.
- Animal without antennae ….. ………………………………………….go to 8.
-
- Animal with one pair of antennae……………………………………… Insecta.
- Animal with more than one pair of antennae………………………….. crustacean.
-
- Animal with pincer –like mouthparts………………………………….. Arachida.
- Animal with sucking mouth parts………………………………….….Acarina.
-
- Animal with long ribbon-like body ……………………….…………….cestoda.
- Animal with circular body………………………………………….. rinoidea).
Use the dichotomous key to identify the taxonomic group of each of the five specimens shown in the drawings.
- In each case, show in sequence the steps (ef 1a,2a,5a, 7b) in the key that you followed to arrive at the identify of each specimen.(5mks)
Animal Steps followed Identity
E ……………………………………….. ……………………………………………………..
F ………………………………….….. ……………………………………………………..
G ……………………………………. ……………………………………………………..
H ……………………………………. ………………………………………………………
J ……………………………………… ……………………………………………………. -
- Name the phylum and the class to which specimen M belongs(2mks)
Phylum:
Class: - Name the observation features that enabled you to place it in the class above.(3mks)
- Name the phylum and the class to which specimen M belongs(2mks)
- With the help of a hand lens, examine the body of specimen M.
- State with a reason in each case he observable features that enable the specimen to be a disease vector.(2mks
- Name one disease transmitted by specimen M.(1mk)
- State two methods that can be used to prevent specimen M from spreading diseases.(2mks)
You are provided with specimens labeled S1 S2 and S3
- Using a scarpel blade split S1 longitudinally and draw a well labeled diagram to show the internal structures.
State your magnification (4mks) - With a reason ,state the class to which the plant from specimen S1 belongs to.
Class(1mk)
Reason(1mk) - Specimen S2 is a germinated seedling of S1.In the table below, name three structures and say which structure in S1 developed into the structure in S2.
Structure in S1 Structure in S2 -
- Using specimens S1 and S3 ,name the type of germination in :-
S1
S3 (1mk) - Give the difference between the this type of germination in (d) (i) above (2mks)
- Account for the type of germination in :-
S1 2mks
S3(2mks)
- Using specimens S1 and S3 ,name the type of germination in :-
MWAKICAN JOINT FORM 4 EXAMINATION
CONFIDENTIAL INSTRUCTIONS:
NB/Requirement instruments:
- About 10ml of substance L.
- 4 clean test tubes on a rack.
- A means of heating
- Test tube holder.
- A scalpel.
- A house fly labeled specimen M.
- A dry bean seed labeled S1.
- A bean seedling labeled S2.
- A maize seedling labeled S3.
- 1% copper (II) sulphate solution.
- 10% sodium hydroxide solution.
- Benedictۥs solution.
- Iodine solution.
Note:
- To make substance L,mix egg albumen and starch.
- Specimen S2 and S3 should be ready 1 week before the exams and must have the seeds intact.
MARKING SCHEME
Food substance Procedure Observation Conclusion Starch To a little of substance L in a test tube,add a little iodine Blue-blackcolour forms Starch present; Reducing sugar To a little of substance L in a test tube add equal amount of Benedict’s solution and heat to boil. Colour remains blue Reducing sugars absent Proteins To a little L,add a little sodium hydroxide followed by a little copper(II) sulphate solution and shake the mixture Purple colour forms Protein present; -
Animal Steps followed Identity E
F
G
H
J1b,2a;
1b,2b,3a,4a,6a,7b;
1b,2b,3a,4a,6b,8a;
1b,2b,3a,4b,5a;
1a,9a;Mollusca
Crustacea;
Arachnida;
Annelida;
Cestoda;-
- Phylum: Arthropoda(1mk)
Class:Insecta (1mk) - Has three body parts;
- Has three pairs of legs
- Has one pair of wings;
- Has one pair of antennae; max 3mks
- Phylum: Arthropoda(1mk)
-
- Presence of legs that walk on contaminated surfaces;
Presence of wings that facilitate movement to and from contaminated surfaces;
Hairly body on which disease causing microorganisms attach;
Has a proboscis to suck /contaminate food; any 2 (2mks) - Cholera/dysentery(1mk)
- Covering food;
Proper disposal of waste /rubbish;
Eradication of houseflies using insecticides; any 2 (2mks)
- Presence of legs that walk on contaminated surfaces;
-
- Magnification – 1mk.
Each correct label-½ mk.
Correct drawing (1mk) - Class: Dicotyledonae;(1mk)
Reason :Has two cotyledons has network veins /has at a tap root system.(1mk)
Structure in S1 Structure in S2 Plumule
Radicle
CotyledonStern system /shoot
Root system;
Seed leaf-
- S1 – Epigeal (1mk)
- S3 – Hypogeal (1mk)
S1 S3 Cotyledons pushed above the ground
Hypocotyl elongatesCotyledons remain in the soil
Epicotyl elongates - S1- has little food store; hence leaves develop early to start photosynthesis ; (2mks)
S3- has a lot of food stored; which is enough for early growth, hence no need for early photosynthesis ;( 2mks)
- Magnification – 1mk.
Download Biology Paper 3 Questions and Answers - Mwakican Joint Pre Mock Examination 2021.
Tap Here to Download for 50/-
Get on WhatsApp for 50/-
Why download?
- ✔ To read offline at any time.
- ✔ To Print at your convenience
- ✔ Share Easily with Friends / Students