Observation

(a) A few candidates could name the vertebrae in mammals with their location. Those that lost marks lost them to the spelling of the vertebrae.

(b) Many candidates could not state the function of the listed parts in a dicotyledonous leaf and the stem of a flowering plant.

(c) Just a few of the candidates could conveniently answer (d). others could not correspond their answers.

The expected answers are:

(a) Vertebrae with corresponding location

Vertebrae	Location
Cervical	Neck
Thoracic	Chest/Thorax
Lumbar	Abdomen/Upper abdomen/loin
Sacral	Hip/lower abdomen
Caudal	Tail/coccyx

Note:
Correct location x 1 mark
Correct vertebrae x 1 mark
Vertebrae spellings must be correct to score

(b) Function of:

  (i) Palisade

- Manufactures food/carries out photosynthesis/site of photosynthesis;
- Contains chloroplasts for photosynthesis;

  (ii) Vascular bundle

- Contains xylem for transport of water/mineral salts/phloem for translocation of manufactured organic substances/hormones;
- Provides mechanical support;

  (iii) Epidermis

- It keeps the leaf’s shape;
- Provides mechanical support;

(c) Function of

  (i) Sieve tube

- Translocates/transports manufactured foods to other parts of the plant;

  (ii) Cortex

- The cells of cortex store starch;
- Outer cortex cells of green stems contain chloroplasts and make food by photosynthesis/chlorophyllus cortex cells manufacture food;

  (iii) Pith

- Cells of pith act as packing/food storage tissues;
- Supports the stem;

(d) Structural differences

(i) External structural differences between stem and root of a maize seedling

 

Stem of a maize seedling	Root of a maize seedling
- Fibrous root absent	fibrous root present;
- Chlorophyllus/greenish	non chlorophyllus/non-greenish;
- Leaves are present	leaves are absent;
- Thicker in size	thinner in size;
- Coleoptiles/shoot sheath present	coleoptiles/shoot sheath absent;
- Coleorhizae/radicle sheath absent	coleorhizae/radicle sheath present.

Note: Points must correspond to score.

(ii) Internal structural differences between stem and root of a maize seedling

Stem of a maize seedling	Root of a maize seedling
- Vascular bundles are scattered	vascular bundles are arranged/in a ring form;
- More vascular bundles	less vascular bundles;
- Cortex is narrower	cortex is wider;
- Pith is absent	pith is present;
- Endodermis absent	endodermis present
- Phloem and xylem do not alternate	phloem alternates with xylem;
- Piliferous layer absent	piliferous layer present

Note: Points must correspond to score.