BioStudyNotesChristmasFinal2

BioStudyNotesChristmasFinal2 - Evolution...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Evolution 1.1 adaptive radiation 1.1.1 Adaptive radiation of plants Adaptive Radiation Of Plants - chloroplasts: autotrophic - important step - oxygen in water and in air, think of consequences for life and for organisms that are autotrophic - moved onto land at end of devonian, scientists found plants with - gametangia: specialized sexual organs - stems: with fluid transport mechanisms can move from roots to the leaves - structural elements: e.g. wood - leaves: centres for photosynthesis - roots: hold to ground, provide access to nutrients and water - stomata: for gaseous exchange - sporangia, seeds Movement onto land requires - stoma - a guard cell adjusts amount of air and CO2 that gets in and out of plant - waterproof: - thick cuticle on surface to prevent evaporation and maintain internal balance - transport - tracheid cells in plants (a) moss (b) s type (c) G type (d) p type - tracheid cell: elongated closed cell of wood having secondary thickening and conducting water. cells are involved in wood, structural and transport Nitrogen - lots of N2 but they are in the form of triple covalent bonds that are hard for organisms to get a hold of - accessible Nitrogen by nitrogen fixation, ammonification, nitrification, denitrification - nitrogen fixation: capture and conversion of atmospheric nitrogen gas into nitro- gen compounds, stored in soil, that can be used by plants - ammonification: bacteria decomposers breaking down amino acids from dead animals and animal wastes into NH4OH - nitrification: process whereby ammonia in wastewater is oxidized to nitrite nad then to nitrate by bacterial or chemical reactions - denitrification: bacterial reduction of nitrite to gaseous nitrogen under anaerobic conditions - Haber-Bosch process made it possible for nitrogen fertilizers to be produced Carnivorous Plants
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Many species of plants are carnivorous, eating insects to obtain additional nutrients. Their approaches: - pitfall traps: attract and drown. e.g. pitcher plant - fly paper: butterwort, drosera - snaptraps: venus flytrap Carnivorous plants: recurring evolutionary theme - thus we cannot use the presence of pitchers or trap apparatus as a good taxonomic feature because they are different evolutionary lines of plants Example: Nepenthes Species - peristome: surrounding entrance to the trap, the “lip”. This is slippery and colourful, at- tracting prey but offering an unsure footing - operculum: lid above peristome. Keeps rain from diluting within pitcher - nectar: underside of pitcher contains nectar glands that attract prey - one way valves and elongated trichomes: prevents insects from crawling out - waxy zone - glandular zone: produces adhesive secretions - digestive glands - target: fruitflies and ants - ultimate goal: get nitrogen from captures Convergence Venus Flytrap (Dionaea) and waterwheel (aldrovanda) evolved from a common ancest- or NB: - dionaea is terrestrial, occurs in south east USA - aldrovanda is aquatic, occurs in Asia - using sequence from nuclear analysis, it was shown that the two species of plants use
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/23/2008 for the course BIO 1222 taught by Professor Maxwell during the Spring '08 term at UWO.

Page1 / 20

BioStudyNotesChristmasFinal2 - Evolution...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online