Biology Names

BIOLOGY 6

Biology:

Names:

Answersto section one

  1. D

  2. E

  3. B

  4. E

  5. B

  6. C

  7. B

  8. C

  9. A

  10. C

Sectiontwo

  1. True

  2. False

  3. True

  4. False

  5. True

  6. True

  7. False

  8. True

  9. False

  10. False

Inthe monocot stem, there are no vascular tissue concentric rings.However, there is distribution of both the xylem and the phloemthroughout the pith of the stem in vascular bundles that arediscrete. However, the dicot stem has vascular bundles that arearranged in form of a ring. Secondly, the vascular tissues scatteraround the ground tissues. The vascular bundles around the ring ofthe stem are close to each other and small in size. They do notcontain cambium and therefore do not allow secondary thickening.While arrangement of the vascular tissue of the dicot stem is in aform of a ring, it does have cambium occurring between the phloem andxylem and therefore it allow as secondary thickening. Another majordifference is that the monocot stem does not have a main variancebetween the cortex and pith. However, a dicot stem has cleardifference between the two. Lastly, a monocot stem does not haverings that form annually. However, in a dicot there is formation ofannual rings, which is as a result of the secondary thickening(Hodson, 2012).

Thedifference between a dicot stem and a dicot root is that theepidermis cells of a dicot stem are thick walled while those of theroot are thin walled. Secondly, the epidermal hairs present in thedicot stem are multicellular while those of the roots areunicellular. Thirdly, the dicot stems have cuticles while the dicotroots do not have cuticles. Fourthly, the dicot epidermis has stomatawhile the roots epidermis does not have. In addition, the dicot stemhas hypodermis that is made of collenchyma while the dicot roots donot have. Furthermore, the dicot stem has endodermis that is waxy intheir appearance and have a rich deposit of starch. While theappearance of a dicot root is circular, it also has casparian stripsand passage cells. The dicot stem has perlcycle that is made ofsclerenchyina that has many layers, while the dicot roots consist ofparenchyma that has only one layer. It also evident that the dicotstem has medullary rays while the dicot root does not have medullaryrays although it has conjuctive tissue. Lastly, the dicot stem has apith while the dicot root does not have (Hodson, 2012).

Thereason as to why a hollow tree can still live for years without anyform of ill effect is because the tree that has a hollow part hasbeen digested by the fungus is converted to a form that the tree canabsorb a rotten pulp. The rotten pulp accumulates on the groundwithin the trunk that is hollow, making the tree to add some roots tothe center to reclaim some parts of it. Secondly the removal of thetrees heart that is dead, leads to changes of the tree from a solidform to a hollow cylinder altering the mechanical stress reaction.This makes the tree more stable and resilient. Another reason is thatthe cutting down of timber reduces strain on the elderly tree and thedecay system making an old hollow tree to withstand storm better thana younger tree as some of its older roots are uprooted (Hodson,2012).

Aknot is a segment of a branch that is enclosed inside a wood. Itoccurs when a section of a branch grows out of one side. Severalyears after, the outer branch thickens but the side branch does notgrow. This makes the main branch to be forced to grow around it,making a section of the branch to be inside the wood. When the treeis cut to form a board the part of branch that was inside the trunkmakes a round knot. It is imperative to note that the board and thewood do not dry up at the same time hence the knot forms a crackafter it dries (Hodson, 2012).

Thefarmer should not worry about the cows walking around the fence afterten years because as much as the height has increased and the tree istaller, the original level of the fence will remain the same.Therefore, the cows would continue walking around the fence as theyused to. The point to note in this regard is that the height of thefence will no change. The point at which the fence was nailed willremain constant.

Tropicaltrees do not experience any winter or summer extremes. Therefore,they grow almost in a similar way through the year and therefore thetree does not have discernible rings (Hodson, 2012).

Reference

Hodson,M. J., &amp Bryant, J. A. (2012). Functionalbiology of plants.Chichester, West Sussex, UK: Wiley-Blackwell.