Form Four Biology Exam - Growth Version 2 (With marking scheme)

Form Four Biology Exam - Growth (Version 2)

FORM FOUR BIOLOGY EXAM – TOPIC: GROWTH (Version 2)

Time: 3 Hours

Instructions:

  • Answer all questions in Sections A and B.
  • Answer two (2) questions only from Section C.
  • Write all answers clearly.

SECTION A (16 Marks)

1. Multiple Choice Questions (10 Marks)

Choose the correct answer and write its letter:

  1. Which of the following best describes germination?
    a) Development of an embryo into a seed
    b) Formation of fruits from flowers
    c) Growth of a seed into a seedling
    d) Cell division during fertilization
  2. Which structure emerges first during seed germination?
    a) Plumule
    b) Cotyledon
    c) Radicle
    d) Endosperm
  3. Which hormone is responsible for promoting seed germination?
    a) Auxin
    b) Gibberellin
    c) Cytokinin
    d) Ethylene
  4. Growth that occurs throughout the life of an organism is called:
    a) Determinate growth
    b) Indeterminate growth
    c) Discontinuous growth
    d) Uniform growth
  5. What is the main function of molting in insects?
    a) Reproduction
    b) Excretion
    c) Oxygen intake
    d) Allow growth
  6. Metamorphosis is a process of:
    a) Cell division
    b) Seed dormancy
    c) Structural change during growth
    d) Asexual reproduction
  7. Which stage of human development follows infancy?
    a) Adolescence
    b) Childhood
    c) Adulthood
    d) Senescence
  8. Which is a feature of complete metamorphosis?
    a) Absence of larval stage
    b) Only two life stages
    c) Egg, larva, pupa, adult
    d) Gradual body transformation
  9. A major event in adolescence is:
    a) Tooth eruption
    b) Puberty
    c) Menopause
    d) Crawling
  10. Which type of growth involves increase in size without a change in form?
    a) Morphological
    b) Isometric
    c) Allometric
    d) Disproportional

2. Matching Items (6 Marks)

Match the stages of human growth with the appropriate characteristics:

List A List B
I. Infancy ___
II. Childhood ___
III. Adolescence ___
IV. Adulthood ___
V. Senescence ___
VI. Puberty ___

List B:

  1. Rapid mental development
  2. Physical body weakening
  3. Stage of independence and reproduction
  4. Fast body growth, teething
  5. Hormonal and sexual maturity changes
  6. Transition from child to adult

SECTION B (54 Marks)

Answer all questions.

3.

(a) Identify and describe the three main types of seed germination. (6 marks)

(b) Explain the significance of seed dormancy in plant survival. (3 marks)

4.

(a) Mary observed a caterpillar shed its skin several times before becoming a butterfly. Explain the importance of this process. (4 marks)

(b) Distinguish between complete and incomplete metamorphosis. (5 marks)

5.

(a) Describe four stages of human growth and development. (6 marks)

(b) Why is adolescence considered a critical stage of growth? (3 marks)

6.

(a) Explain two differences between isometric and allometric growth with examples. (4 marks)

(b) What are three advantages of indeterminate growth in plants? (5 marks)

7.

(a) During an experiment, students observed that seeds in dark and light conditions both germinated. What conclusion can be drawn from this? (4 marks)

(b) Identify five internal or external factors required for successful germination. (5 marks)

8.

(a) Describe the role of enzymes in seed germination. (4 marks)

(b) List and explain five forms of growth observed in organisms. (5 marks)

SECTION C (30 Marks)

Answer two (2) questions only.

9.

With the aid of labeled diagrams, compare and contrast complete and incomplete metamorphosis. (15 marks)

10.

Explain five differences between determinate and indeterminate growth, and discuss how each applies to animals and plants. (15 marks)

11.

Discuss six stages of human development from birth to old age, highlighting physical and emotional changes at each stage. (15 marks)

Form Four Biology Exam - Growth (Version 2) Answers

FORM FOUR BIOLOGY EXAM – TOPIC: GROWTH (Version 2) Answers

SECTION A (16 Marks)

1. Multiple Choice Questions (10 Marks)

  1. Which of the following best describes germination?
    c) Growth of a seed into a seedling
  2. Which structure emerges first during seed germination?
    c) Radicle
  3. Which hormone is responsible for promoting seed germination?
    b) Gibberellin
  4. Growth that occurs throughout the life of an organism is called:
    b) Indeterminate growth
  5. What is the main function of molting in insects?
    d) Allow growth
  6. Metamorphosis is a process of:
    c) Structural change during growth
  7. Which stage of human development follows infancy?
    b) Childhood
  8. Which is a feature of complete metamorphosis?
    c) Egg, larva, pupa, adult
  9. A major event in adolescence is:
    b) Puberty
  10. Which type of growth involves increase in size without a change in form?
    b) Isometric

2. Matching Items (6 Marks)

List A List B
I. Infancy d) Fast body growth, teething
II. Childhood a) Rapid mental development
III. Adolescence f) Transition from child to adult
IV. Adulthood c) Stage of independence and reproduction
V. Senescence b) Physical body weakening
VI. Puberty e) Hormonal and sexual maturity changes

SECTION B (54 Marks)

3.

(a) Identify and describe the three main types of seed germination. (6 marks)

  • Epigeal germination: Cotyledons are raised above the ground, becoming photosynthetic; e.g., beans.
  • Hypogeal germination: Cotyledons remain below the ground; the plumule emerges; e.g., maize.
  • Viviparous germination: Seeds germinate while attached to the parent plant; e.g., mangroves.

(b) Explain the significance of seed dormancy in plant survival. (3 marks)

Seed dormancy delays germination until favorable conditions, prevents premature growth in harsh seasons, and ensures seed dispersal over time, enhancing plant survival and population stability.

4.

(a) Mary observed a caterpillar shed its skin several times before becoming a butterfly. Explain the importance of this process. (4 marks)

Molting allows the caterpillar to grow by shedding its rigid exoskeleton, which restricts size increase. It enables physical development, facilitates metamorphosis stages, and supports tissue growth and differentiation.

(b) Distinguish between complete and incomplete metamorphosis. (5 marks)

  • Complete metamorphosis: Has four stages (egg, larva, pupa, adult); e.g., butterflies. Larva differs significantly from adult in form and function.
  • Incomplete metamorphosis: Has three stages (egg, nymph, adult); e.g., grasshoppers. Nymph resembles adult but lacks wings and reproductive organs.

5.

(a) Describe four stages of human growth and development. (6 marks)

  • Infancy: Rapid physical growth, teething, and motor skill development (birth to 2 years).
  • Childhood: Steady growth, rapid mental and social development (2–12 years).
  • Adolescence: Puberty, sexual maturity, and emotional changes (12–18 years).
  • Adulthood: Physical and mental maturity, independence, and reproduction (18–60 years).

(b) Why is adolescence considered a critical stage of growth? (3 marks)

Adolescence involves puberty, leading to sexual maturity, hormonal changes, and emotional development. It shapes identity, social roles, and physical capabilities, impacting lifelong health and behavior.

6.

(a) Explain two differences between isometric and allometric growth with examples. (4 marks)

  • Isometric growth: Proportional increase in size, maintaining shape; e.g., growth of a fish’s body length and width.
  • Allometric growth: Disproportional growth, changing form; e.g., human head grows slower than body during childhood.

(b) What are three advantages of indeterminate growth in plants? (5 marks)

  • Allows continuous growth, adapting to environmental changes.
  • Enables regeneration of damaged parts, enhancing survival.
  • Supports increased reproductive output over time.

7.

(a) During an experiment, students observed that seeds in dark and light conditions both germinated. What conclusion can be drawn from this? (4 marks)

Light is not always essential for germination. Some seeds germinate independent of light, relying on internal factors like water, oxygen, and temperature, as seen in certain species like beans.

(b) Identify five internal or external factors required for successful germination. (5 marks)

  • Water: Activates enzymes and softens seed coat.
  • Oxygen: Supports respiration for energy production.
  • Temperature: Optimal range triggers metabolic processes.
  • Viable embryo: Ensures genetic potential for growth.
  • Seed coat permeability: Allows water and oxygen entry.

8.

(a) Describe the role of enzymes in seed germination. (4 marks)

Enzymes like amylase break down stored starch into sugars for energy. Proteases degrade proteins into amino acids, and lipases convert lipids into usable forms, supporting embryo growth.

(b) List and explain five forms of growth observed in organisms. (5 marks)

  • Cell division: Increases cell number; e.g., meristem growth in plants.
  • Cell elongation: Increases cell size; e.g., stem elongation.
  • Differentiation: Cells specialize; e.g., xylem formation.
  • Morphogenesis: Development of form; e.g., leaf shape formation.
  • Maturation: Functional development; e.g., reproductive organs in animals.

SECTION C (30 Marks)

Answer two (2) questions only.

9. With the aid of labeled diagrams, compare and contrast complete and incomplete metamorphosis. (15 marks)

Complete Metamorphosis:

  • Four stages: egg, larva (e.g., caterpillar), pupa (e.g., chrysalis), adult (e.g., butterfly).
  • Larva differs significantly from adult in structure and function.
  • Pupa is a non-feeding, transformative stage.
  • Example: Butterflies, beetles.

Incomplete Metamorphosis:

  • Three stages: egg, nymph, adult.
  • Nymph resembles adult but lacks wings and reproductive organs.
  • Gradual transformation without pupal stage.
  • Example: Grasshoppers, cockroaches.

Diagram Note: Include labeled diagrams showing complete metamorphosis (egg → larva → pupa → adult) and incomplete metamorphosis (egg → nymph → adult). Label key features like larval differences and absence of pupa in incomplete metamorphosis.

10. Explain five differences between determinate and indeterminate growth, and discuss how each applies to animals and plants. (15 marks)

  • Duration: Determinate growth stops at maturity (e.g., human height); indeterminate continues lifelong (e.g., tree growth).
  • Regulation: Determinate is genetically fixed (e.g., bird wing size); indeterminate is environmentally influenced (e.g., plant branching).
  • Regeneration: Indeterminate allows regeneration (e.g., plant regrowth); determinate does not (e.g., human limbs).
  • Reproductive capacity: Indeterminate increases reproductive output (e.g., larger plants produce more seeds); determinate is fixed (e.g., mammals).
  • Occurrence: Determinate common in animals (e.g., dogs); indeterminate typical in plants (e.g., vines).

Application: Animals like humans exhibit determinate growth, stopping at adulthood. Plants like trees show indeterminate growth, allowing continuous size increase and adaptation.

No comments

Post a Comment

© all rights reserved
made with by templateszoo