a. State three features of the small intestine that increase the rate of absorption of...

Explanation

a. Features of the small intestine that increase the rate of absorption of digested food

- Ridges/furrows on inner linings;

- Small finger-like projections/villi;

- Minute projections/microvilli on the villi;

- Thin epithelial lining of the villi;

- Highly vascularised/well supplied with blood;

- Intestine is long/it has a large surface area.

b. Fate of glucose formed in a plant during photosynthesis

- Glucose combines with Nitrogen/Sulphur/Phosphorus to form proteins for growth;

- Glucose is stored as starch;

- Glucose is oxidised to form carbon dioxide/water/energy in respiration;

- Glucose is also converted into lipids/cellulose which is stored.

c. Mode of feeding of

(i) Euglena

- Exhibits both autotrophic and heterotrophic modes of nutrition;

- In autotrophic mode of feeding, the chlorophyll in its stellate chloroplast absorbs sunlight energy;

- And the dissolved carbon dioxide in the pond water diffuses into the cell of Euglena;

- Inside the chloroplast, the absorbed solar energy/sunlight is used in the synthesis of glucose from water and carbon dioxide;

- Glucose is converted into starch and stored in the paramylum granules;

- In heterotrophic mode of feeding, it takes in organic matter/diatoms e.t.c.;

- Through the gullet;

- And digests it in the reservoir.

(i)Spirogyra

- Manufactures its own food through photosynthesis;

- Its spiral chloroplast/chlorophyll absorbs the sunlight energy;

- It absorbs carbon dioxide from water/its environment to manufacture food;

- The manufactured food is used;

- while the rest/excess is stored in its pyrenoid in the form of starch;

d. Characteristics of an Estuarine Habitat

- It is shallow;

- It has a high level of nutrients;

- Salinity/pH/O2 level fluctuates;

- Turbidity is high during rainy season;

- It is affected by tides;

- Species diversity is low;

- Muddy/soft soil/substratum

d. Differences between an aquatic and terrestrial habitat