Question 1
(a) (i) Explain briefly sexual reproduction in Rhizopus. [8 marks]
(b) A student suddenly stepped on a big snake, he cried for help and ran away
.
(i) Name the hormone produced in the body for the reaction.
(ii) In which part of the human body is the hormone named in 1 (a) (i) produced?
(iii) State five changes that must have taken place as a result of the hormone named in 1 (a) (i). [7 marks]
(c)
(i) In a tabular form, state three differences between the excretion in flowering plants and excretion in humans.
(ii) List two organelles found in a plant cell that are responsible for the excretion of metabolic wastes. [5 marks]Observation
This question was the least popular question among the candidates. Most of the candidates that attempted it did not do it well.
Candidates attempted other aspects fairly.
The expected answers are:
(a) Sexual reproduction in Rhizopus
(b) (i) Name of hormone
Adrenalin/Adrenaline
NOTE: Spelling must be correct to score
(ii) Part where hormone is produced
Adrenal gland/Medulla
NOTE: Spelling must be correct to score
(iii) Changes that must have taken place as a result of the hormone
(c) (i) Differences between excretion in flowering plants and excretion in humans
Flowering plants |
Humans |
- No definite excretory organs |
Definite excretory organs/presence of kidney/liver/skin; |
- Excretory products produced in small quantities |
Excretory products produced in large quantities; |
- Excretory products released at a slower rate |
Excretory products released at a faster rate; |
- Most excretory products/tannins/resins/alkaloids/ |
Most excretory products are completely removed; |
- Some excretory products/carbondioxide/oxygen/ |
Some excretory products/urea/uric acid cannot be reused; |
- Excretory products are derived from simple |
Excretory products are derived from complex organic molecules. |
NOTE: No Tabulation minus (-) 1 mark.
(ii) Organelles in plant cells responsible for excretion of metabolic wastes
Mitochondrion/ mitochondria; chloroplast/chloroplasts
NOTE: Spelling must be correct to score