(a) Sexual reproduction in Rhizopus - By conjugation;

It is usually between two strains of hyphae
Known as + and - plus and minus/ opposite mating types
The hyphae come in contact
And produce small projections of their walls
Which develop into progametangia with several nuclei
The two progametangia enlarge
Each progametangium develops a cross wall to divide into two parts; the gametangium and suspensor
Subsequently the wall dissolves/breaks; and their contents/nuclei fuse to form a zygote
The zygote develops a thick wall to form a resistant zygospore
The zygospore germinates during favourable / damp / wet condition
Into hyphae which bear sporangia.

(b) (i) Name of hormone Adrenalin /Adrenaline
(ii) Part where hormone is produced Adrenal gland/Medulla.
(iii) Changes that must have taken place as a result of the hormone

Increase in heart beat
Increase in rate of respiration
Arterioles of skin and alimentary canal constrict
Dilation of blood vessels that cause more blood to flow to the muscles/heart/lungs
Increase in muscular tone/voluntary muscles become tensed
Glycogen is converted to glucose/increase in blood sugar level
To produce more energy
Dilation of pupils of the eye
Momentary freight/fear/anxiety/heavy breathing
Spleen releases more Red Blood Cells from its reserve
Increase in blood pressure

(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
waste products include tannins/resins/alkaloids/gums etc	waste products include urine/urea/sweat/salts etc
Excretory products produced in small quantity	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/gums are stored	most excretory products are completely removed
some excretory products/carbondioxide/oxygen/water vapour can be reused	some excretory products/urea/uric acid cannot be reused
Excretory products are derived from simple organic molecules	excretory products are derived from complex organic molecules.

(ii) Organelles in plant cells responsible for excretion of metabolic wastes.
Mitochondrion/ mitochondria; chloroplast/ chloroplasts.