Questions
Instructions to candidates:
- Answer all the questions in section A and B
- You are required to spend the first 15 minutes of the 1 ¾ hours allowed for this paper reading the whole paper carefully.
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- Place 2ml of bicarbonate indicator in a clean test tube. Add dilute hydrochloric acid drop by drop and shake after each drop till there is a permanent color change.
- State the resulting color 1mk
- To the mixture obtained above, now add sodium hydroxide solution dropwise until there is a permanent color change. Record your observations 1mk
- From your observations in a) i) and a) ii) above, what is the nature of the bicarbonate indicator 1mk
- Place 10ml of a fresh bicarbonate indicator in boiling tube. Using a drinking straw, bubble air through the bicarbonate indicator until there is color change
- Record your observation 1mk
- What does the color obtained in b) i) above suggest about the nature of the gas breathed out 1mk
- Rinse the measuring cylinder and use it to place 2ml of lime water solution in a clean test tube. Rinse the drinking straw in (b) above and use it to bubble air through lime water solution
- Record your observation 1mk
- Suggest the identity of the gas that give rise to the observations above 1mk
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- Name the physiological process in cells that leads to formation of gas named in (c)( ii) above 1mk
- Write down a word equation for the process named in (d) (i) above 1mk
- What is the importance of the identified process in cells of living organisms 1mk
- Place 2ml of bicarbonate indicator in a clean test tube. Add dilute hydrochloric acid drop by drop and shake after each drop till there is a permanent color change.
- Below are photographs of two seedlings labeled K and L. Examine them.
- Given that the two plants belongs to the same class, name the class and give a reason based on the observable features in any of the two seedlings or both. 2mks
Class
Reason(s) -
- State giving a reason, the type of germination that occurs in each of the two seedlings 4mks
- Explain how the two types of germination you have stated in (b) (i) above occur 2mks
- Name the parts labelled H and G on the seedling 2mks
- As germination progresses, both seedlings straightens. Explain how this occurs. 4mks
- Name the type(s) of root system that will develop in the two seedlings 1mk
- State another observation that will be made as seedling L straightens 1mk
- Given that the two plants belongs to the same class, name the class and give a reason based on the observable features in any of the two seedlings or both. 2mks
- The photographs below are specimens from the same animal of two different bones each shown in two views. Examine them.
- Identify the two specimens 2mks
Specimen V……………………………………………………………………………………….
Specimen W……………………………………………………………………………………… - Give four observable differences between bones V and W 4mks
Bone V Bone W - Name the structure that articulates with part labeled A 1mk
- State two roles of opening labeled B 2mks
- Name the part labelled E and state its role 2mks
Name
Role - Which of the labelled part(s) are used for articulation with adjacent vertebra 1mk
- State a common role of the parts labelled H and J 1mk
- Which of the labeled part(s) is(are) used for muscle attachment 1mk
- Identify the two specimens 2mks
Confidential
Each student should be provided with the following
- 25ml bicarbonate indicator
- Lime water
- A drinking straw
- 2 test tubes
- 10ml measuring cylinder
- A boiling tube
- Dilute hydrochloric acid
- Dilute sodium hydroxide
Marking Scheme
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- yellow
- red
- acid-base indicator
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- color change from red to yellow
- the gas is acidic
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- white precipitate formed
- carbon iv oxide
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- respiration(aerobic)
- Glucose + oxygen carbon iv oxide + water + energy
- for provision of energy
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- class- Dichotyledonae
Reasons- presence of two cotyledons in specimen L
- Net venation on plumule/leaves of specimen L(reticulate)
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- K- hypogeal; cotyledon remains in the ground
L- epigeal ; cotyledons brought above the ground - K- epicotyl elongates pulling the plumule leaves and the shoot tip out of the cotyledons and out of the ground leaving the cotyledons in the soil.
L- Hypocotyl elongates pulling the cotyledons enclosing the plumule above the ground
- K- hypogeal; cotyledon remains in the ground
- H –Epicotyl
G- hypocotyls - As the bent parts exposed to sunlight, more light on the upper side causes auxins to migrate to the lower side; the increased auxin concentration on the lower side , stimulates faster elongation of cells; on the lower side leading to straightening og the seedling
- Both will develop a taproot system
- the cotyledons will part and the leaves will expand and spread out
- class- Dichotyledonae
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- V- Atlas
W- Axis -
Bone V Bone W Has a wider neural canal Narrower neural canal Has a very small centrum Prominent centrum Has a greatly reduced neural spine Has a broad neural spine Lack odontoid process Has an odontoid process - occipital condyles of the skull
- passage of the spinal cord and fitting of odontoid process of the axis
- name- odontoid process
role- it fits into the canal of the atlas and allows for rotational movements of the head - C,F and K ( mark any one)
- protection of the spinal cord
- D and G ( mark any one)
- V- Atlas
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