BIOLOGY MARKING SCHEME
SECTION A: (16 Marks)
(i) The organelle where ATP production from ADP occurs:
The correct answer is B. Mitochondrion
(ii) Reason for increased breathing rate during exercise:
The correct answer is E. Oxygen required by the active muscles.
(iii) Term for a plant cell that has lost too much water:
The correct answer is B. Plasmolysis
(iv) Substance that does NOT pass across the placenta from mother to fetus:
The correct answer is B. Red blood cells
(v) Red eyes in Drosophila genetics is an example of:
The correct answer is C. Discontinuous variation
(vi) Hormone recommended for low blood sugar:
The correct answer is C. Glucagon
(vii) Chromosome number in a human fertilized egg for a male child:
The correct answer is B. 22 pair + xy
(viii) Microscope part affected by poor light reflection:
The correct answer is B. Mirror
(ix) Genotype for homozygous recessive in a Punnett square:
The correct answer is B. Two small letters of the same letter in the alphabet
(x) General reason for organisms to remove waste products:
The correct answer is D. To maintain homeostatic condition in the body
SECTION B: (54 Marks)
(11) (a) Measures to help adolescents behave well:
Seek guidance and counseling from trusted adults (parents, teachers, counselors).
Engage in positive activities like sports, arts, or clubs.
Develop strong communication skills to express their feelings.
Practice self-control and decision-making skills.
Surround themselves with positive peer groups.
(11) (b) Considerations for a dialog with a young brother:
Use age-appropriate language.
Be patient and listen actively.
Show empathy and understanding.
Provide clear and honest information.
(12) (a) Adaptive features of the urinary system:
Nephrons: Functional units for filtration and reabsorption.
Extensive network of blood vessels: For efficient transport of substances to and from the kidneys.
Loop of Henle: Creates a concentration gradient for water reabsorption.
Collecting ducts: Regulate water balance.
(12) (b) (i) Detection of renal calculi:
X-rays, ultrasound, or CT scans.
(12) (b) (ii) Effect of untreated renal calculi:
Severe pain, urinary tract infections, kidney damage, blockage of urine flow.
(12) (b) (iii) Treatment of renal calculi:
Pain medication, increased fluid intake, shock wave lithotripsy, surgery.
(12) (c) Causes of renal failure:
Diabetes
High blood pressure
(13) (a) Distinctive features of Filicinophytes (Ferns):
Spores for reproduction (not seeds)
Vascular tissue (xylem and phloem)
Presence of rhizomes (underground stems)
(13) (b) Characteristics of Fern Plants (Diagram required):
Rhizome: Horizontal underground stem.
Roots: Adventitious roots growing from the rhizome.
Fronds: Large, divided leaves.
Sori: Clusters of sporangia on the underside of fronds (where spores develop).
(14) (a) Differences between Meiosis and Mitosis:
Export to Sheets
(14) (b) Parts of a seed:
Testa: Seed coat for protection.
Cotyledons: Seed leaves that store food.
Plumule: Embryo shoot.
Radicle: Embryo root.
(15) (a) Correct ways of handling drugs:
Store drugs in a cool, dry place.
Keep drugs out of reach of children.
Follow the prescribed dosage and instructions.
Check expiry dates before use.
(15) (b) Roles of hormones:
Hydrocortisone: Regulates metabolism and stress response.
ADH (Antidiuretic Hormone): Regulates water balance in the kidneys.
Thyroxine: Controls metabolic rate.
Parathyroid Hormone: Regulates calcium levels in the blood.
Aldosterone: Regulates sodium and potassium levels in the blood.
(16) (a) Second Mendelian law of inheritance:
The law of independent assortment states that alleles of different genes assort independently of one another during gamete formation.
(16) (b) (i) Explanation for pink flowers:
This is an example of incomplete dominance (or blending inheritance), where neither the red (G) nor white (B) allele is completely dominant, resulting in a blended phenotype (pink) in the F1 generation.
(16) (b) (ii) F2 generation ratios:
Genotypes: GG (Red), GB (Pink), BB (White)
Phenotype Ratio: 1 Red : 2 Pink : 1 White
Calculation for 1000 plants:
Red: 1/4 of 1000 = 250
Pink: 2/4 of 1000 = 500
White: 1/4 of 1000 = 250
SECTION C: (30 Marks)
(17) Developmental stages of a plant:
Germination: Seed sprouts and develops into a seedling.
Seedling Stage: Young plant with initial leaves and root system.
Vegetative Growth: Development of stems, leaves, and roots.
Reproductive Stage: Flowering and development of fruits and seeds.
Senescence: Aging and eventual death of the plant.
(18) (a) Causes of Asthma:
Allergens (pollen, dust mites, pet dander)
Respiratory infections
Irritants (smoke, fumes)
Exercise
(18) (b) Signs of Asthma:
Wheezing
Coughing
Shortness of breath
(18) (c) Prevention/Control of Asthma:
Avoid triggers
Use inhalers as prescribed
Maintain a healthy lifestyle
Monitor breathing and seek medical attention when necessary.
(19) Advantages of breastfeeding over bottling:
Provides essential nutrients and antibodies.
Reduces the risk of infections in the baby.
Promotes bonding between mother and child.
Aids in the development of the baby's immune system.
Can help the mother's uterus return to its normal size.
Is more convenient and cost-effective.
Reduces the risk of allergies in the baby.
HISTORY EXAM PAPER.
SECTION A: (16 Marks)
Here are the answers to the multiple-choice questions:
i) b) His excellency Amara Essy
ii) c) Archeology
iii) c) America, France, Russia, Britain and China
iv) d) The guest were much determined to conquer the natives
v) a) 25th June`1975
vi) d) Tenant
vii) c) Introduction of legitimate trade
viii) a) Assisting Africans to know French language
ix) e) Overpopulation
x) e) Spreading Christianity, adventure and trade
PHYSICS FORM FOUR JOINT PRE-MOCK EXAMINATION:
SECTION A (16 Marks)
Answer all questions in this section.
1. Multiple Choice Questions (10 Marks)
Write the letter of the correct answer next to each item number.
2. Matching Items (6 Marks)
Match List A with List B.
Hakika, hapa kuna majibu ya Sehemu A ya mtihani wa Kiswahili:
e) Prediketa
b) Sita
d) Kupanda na kushuka kwa mawimbi ya sauti
b) Takriri
c) Lugha
c) Amemranda mama yake
b) Njeo
a) KI – VI
a) Aya
a) Dhamira
THE CHEMISTRY FORM FOUR EXAM PAPER.
Here's the breakdown of question 1, with the correct answers:
i) The answer is c) Retort stand
ii) The answer is b) Collar
iii) The answer is b) Hypothesis
iv) The answer is c) A metal nitrate
v) The answer is c) Four atoms of hydrogen and two atoms of oxygen
vi) The answer is a) The direction of the reaction
vii) The answer is b) Pat of the acid radical is replaced by a metal
viii) The answer is b) Strength
ix) The answer is c) Electroplating
x) The answer is a) Calcium carbonate powder has large surface area than marble chips
LITERATURE IN ENGLISH FORM FOUR JOINT PRE-MOCK EXAMINATION:
SECTION A (16 Marks)
Answer all questions in this section.
1. Multiple Choice Questions (10 Marks)
Write the letter of the correct answer next to each item number.
2. Matching Genre to Conflict (6 Marks)
Match List A with List B.
CLICK HERE TO OPEN LITERATURE IN ENGLISH
CIVICS FORM FOUR PRE-MOCK EXAMINATION:
(i) Skills to guide the student to reach an agreement:
The correct answer is B. Negotiation skills
(ii) Item Civics helps in cultivating awareness:
The correct answer is D. Economic issues
(iii) What guides you to conclude the election was free and fair:
The correct answer is E. The registered voters freely cast their votes through a secret ballot box
(iv) How Bonge can be named:
The correct answer is E. A corrupt worker
(v) Major consequences of destroyed school furniture:
The correct answer is E. Increased cost in buying new furniture and repaired
(vi) Negative social-cultural practice:
The correct answer is D. Gender discrimination
(vii) Factors that may influence youth's improper behavior:
The correct answer is B. Lack of parental care
(viii) Position Mrs. Kalinga holds:
The correct answer is C. District council
(ix) Action constitution approves on President's second refusal:
The correct answer is D. The parliament dissolves the parliament and order new election
(x) Why Magna Carta has a great contribution:
The correct answer is B. Provided for limitation of powers
(xi) Matching Column A with Column B:
A community based financial organization that mobilizes funds and provides soft loans. - D. SACCOS
An organization which mobilizes savings from employee and pays them after retirements - C. Social security fund
An organization which make financial transactions like buying and selling local foreign currency. - B. Commercial bank
A financial organization which protects the value of the currency and monitor exchange rates in the country. - E. The Central Banks
A financial organization which deal with compensation of losses and risk management. - F. Insurance companies
CLICK HERE TO OPEN BASIC MATHEMATICS
No comments
Post a Comment