DESCRIBE THE ADAPTATIONS OF THE ILEUM TO ITS FUNCTION (20 MARKS)

-
  • Has secretory glands/crypts of lieberkuhn which secretes enzymes (maltase/sucrase/lactase/peptidase/lipase to complete digestion of sugars/proteins/lipids.
  • Goblet cells secrete mucus which allows for smooth movement of food and protect wall of ileum from action of digestive enzymes
  • Very long to provide large surface area for absorption.
  • Highly folded/coiled to slow movement of food to allow more time for digestion/absorption/ and to increase surface area for absorption.
  • Has numerous villi which increase surface area for absorption/microvilli which further increase surface area for absorption.
  • Ileum wall/villi have thin epithelium which is only one cell thick to reduce distance over which digested food has to diffuse.
  • Villi are highly vascularised/have a rich network of blood capillaries for rapid transport from small intestines and maintain a steep concentration gradient for rapid absorption.
  • Villi have lacteals for absorption of fatty acids and glycerol
  • Cells of ileum wall have a large count of mitochondria to release energy for active uptake of some food substances across the epithelium.

Max 20mks

Comments

  1. geeteeMarch 25, 2018 at 7:40 AM

    nice points

    ReplyDelete
  2. UnknownJune 23, 2018 at 8:30 AM

    Nice points though they should be 20 like the marks given

    ReplyDelete
  3. UnknownJune 23, 2018 at 8:30 AM

    Nice points though they should be 20 like the marks given

    ReplyDelete
    Replies
    1. UnknownDecember 2, 2018 at 11:48 AM

      They have to be twenty points boss. One feature mentioned, accompanied by its role and any other description are all marks so 20 marks can come from even 5 points. Sawa?

      Delete
    2. UnknownDecember 2, 2018 at 11:49 AM

      *they dont have to be 20

      Delete
  4. UnknownAugust 18, 2018 at 12:19 AM

    noooice
    gooda jooobu

    ReplyDelete
  5. UnknownOctober 4, 2018 at 9:59 AM

    excellent

    ReplyDelete
  6. UnknownNovember 26, 2018 at 12:43 AM

    Good notes

    ReplyDelete
  7. UnknownJanuary 21, 2019 at 7:17 PM

    Thanks for the lesson

    ReplyDelete
  8. UnknownJanuary 21, 2019 at 7:17 PM

    Thanks for the lesson

    ReplyDelete
  9. AnonymousFebruary 13, 2019 at 1:56 PM

    nice point

    ReplyDelete
  10. UnknownFebruary 28, 2019 at 1:16 PM

    Nice point

    ReplyDelete
  11. UnknownMay 15, 2020 at 12:35 AM

    Thank you for your points

    ReplyDelete
  12. UnknownMay 19, 2020 at 2:38 AM

    thenx for everything

    ReplyDelete
  13. UnknownMay 28, 2020 at 11:05 AM

    Nice and thank you

    ReplyDelete
  14. UnknownJuly 28, 2020 at 4:55 AM

    Nice points but too long please shorten

    ReplyDelete
  15. UnknownAugust 19, 2020 at 12:52 PM

    I don't like this point because they are pointless

    ReplyDelete
  16. UnknownApril 19, 2021 at 7:24 AM

    Not bad at all

    ReplyDelete
  17. UnknownMay 13, 2021 at 11:30 AM

    Thenks for your assistance

    ReplyDelete
  18. UnknownOctober 1, 2021 at 7:19 AM

    nice points swty but too long



    ReplyDelete
  19. UnknownDecember 2, 2021 at 9:22 AM

    Nice points

    ReplyDelete
  20. UnknownDecember 3, 2021 at 6:12 PM

    Good points sir.most not be 20 to make up,it also depends on how you expanciate the points(each point =2mks)

    ReplyDelete
  21. UnknownMarch 16, 2022 at 6:52 AM

    Nce job

    ReplyDelete
  22. UnknownApril 14, 2022 at 11:48 PM

    I appreciate your services.

    ReplyDelete

Post a Comment

Popular posts from this blog

(a) Define digestion. [2 m] (b) Describe the digestion of a piece of ugali in a human digestive system from the mouth until its assimilation. [18mks]

-
(a) Define digestion It is break down of complex insoluble; v food substance into simple soluble food substances; v 2max (b) Describe the digestion of ugali; Digestion of ugali begins in the mouth;v ugali is chewed by the teeth to increase large surface areav for action of salivary amylase / ptyalin; vThe food mixes with saliva produced by salivary glands;v Saliva contains mucus and enzyme ptyalin. Mucus moistens, softens and lubricates the food;v ptyalin speeds up the conversion of starch to maltose;v ugali is made into bolus in the mouth;v The bolus moves along the oesophagus and prestalsis / by contraction and relaxation of circular and longitudinal muscles into the stomach;v The digestion continues until ugali become acidic since the stomach does not contain carbohydrase / carbohydrate digesting enzymes no digestion of ugali takes place here.v Ugali now
Read more

Explain how structures of the human ear are adapted to their functions. (20 marks)

-
Image
The pinna;- is funnel shaped to trap sound waves; cartilaginous to maintain the funnel shape; collects and directs sound waves into the external auditory meatus ear; The external auditory canal; - a tube connected to the pinna that directs sound waves from the pinna to the eardrum lining the auditory canal; has hair that trap foreign particles; The canal contains wax-secreting cells; and hair which traps dust particles; and pathogenic bacteria hence prevent them from getting into the ear; The eardrum; - has a thin tough membrane; that easily vibrates when hit by sound waves; transferring them into vibrations. The ear ossiscles; - they act like a layer and they easily move forward and backward to amplify sound vibrations that hit them; The suspensory ligaments; - suspends the ear ossicles and prevents excessive vibration that would otherwise damage the inner parts of the ear; The eustachian tube - it connects the middle ear with the pharynx; and it equalises air pressure between
Read more

EXPLAIN HOW ABIOTIC FACTORS AFFECT PLANTS. (20MKS)

-
 Explain how abiotic factors affect plants. (20mks) Abiotic factors. Wind; -On a windy day rate of transpiration increases since wind carries away water vapour leaving surrounding of leaves with low humidity; the lower the humidity the more the space in the atmosphere for water molecules to occupy. - Wind disperse fruits, seeds and spore; - Wind is an agent of pollination. - Strong winds break branches of trees and may even uproot some trees; Temperature; -Enzymes work best at optimum temperature; changes in temperature hence influence rate of photosynthesis/respiration; and other enzyme controlled biological reactions. -In aquatic environment temperature affects the percent of dissolved gases. Light; - green plants need light for photosynthesis; - some plants need light for flowering; photoperiodism; - some seeds (lettuce) require light for germination; - light affects opening and closing of stomata; which affects transpiration; gaseous exchange and photosynthesis.
Read more