Mastering KCSE Biology with Comprehensive Topical Questions and Answers
K.C.S.E Biology Q & A - MODEL 2012PP2QN03
(a) In an investigation, equal amounts of water was placed in. three test-tubes labelled G, H and J. Pondweeds of equal length were dropped in each test tube. The test-tubes were then placed in identical conditions of light and carbon (IV) oxide at different temperatures for five minutes. After the five minutes, the bubbles produced in each test-tube were counted for one minute. The results were as shown in the table below.
​(i) Name one requirement for this process that is not mentioned in the investigation.
(ii) Name the gas produced in this investigation. (iii) Account for the results in test-tubes H and J. (b) State two ways in which the human intestinal villus is adapted to its function.
answers
​(a) (i) chlorophyll;
(ii) oxygen; (1 mark) (iii) Test tube H is at optimum temperature for enzyme activity; hence high rate of photosynthesis/more bubbles. In test tube J most enzymes have been denaturedby the high temperature; hence low rate of photosynthesis/fewer bubbles. (b) — The villus epithelium is thin; for faster diffusion of dissolved food substances; — The epithelium has goblet cells; which produce mucus to lubricate food passage; — They have microvilli; which further increase their surface area for absorption; Have lacteal; for absorption of fatty acid & glycerol/transportation of lipids; Highly vascularised; for absorption of digested food.
0 Comments
Leave a Reply. |
Archives
December 2024
Categories
All
TOPICSFORM 1
Form 2
Form 3
Form 4
|
We Would Love to Have You Visit Soon! |
Hours24 HR Service
|
Telephone0728 450425
|
|
8-4-4 materialsLevels
Subjects
|
cbc materialsE.C.D.E
Lower Primary
Upper Primary
Lower Secondary
Upper Secondary
|
teacher support
Other Blogs
|