BIOL 1070 Final: Biol 1070 Exam Review 2012.docx

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taupellama890

8 Apr 2012

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Changes to rivers: drainage and irrigation practices causing erosion of riverbanks and build-up of sediments in rivers, damns and channels affecting water flow effecting also local freshwater biodiversity. Over-exploitation of mussels for pearls or shells- buttons and fish hosts. Changes in water temperature: climate change unknown impact. Changes in predation on mussels or host fish. Simple lures- modified mantle tissue mimics fish or invertebrate prey to catch fish attention to attract host. Veliger larvae: released into water- doesn"t need fish host, settles on to any solid surface. Genetic variation- differences at the dna level among individuals within a population or species, can change within populations in by: mutation, natural selection, genetic drift, gene flow. Natural selection- non-random differences in survival and/or reproduction among individual entities on the basis of differences in heritable characteristics. Genetic drift- evolution by chance due to sampling error, random changes in allele frequencies in a population due to chance.

Related Questions

With reference to flatworms answer the following parts :

a.What are the best known representatives of the Platyhelminth phylum?

b. What is the main external morphological feature that differentiates platyhelminthes from other worms (nematodes)?

c.How many germ layers make up the body of platyhelminthes? How are they classified according to this feature?

d.What are the types of digestion and digestive system of platyhelminthes?

e.How are nutrients distributed by the digestive system in planaria?

f. How is gas exchange carried out in flatworms?

g.Poriferans and cnidarians do not have excretory systems. Do platyhelminthes have an excretory system?

h.What is an example of a freshwater flatworm? What physiological problem must these animals solve when living in that environment?

i.Is the nervous system of platyhelminthes more or less sophisticated than that of cnidarians1? What are the main neural structures found in flatworms? How is this neural organization important for the diversity of ecological niches explored by species of the phylum?

j.What is cephalization? How does lateral symmetry favor cephalization?

k.Do platyhelminthes use sexual or asexual reproduction?

l.How can asexual reproduction in planaria be described?

m.Are flatworms monoecious or dioecious?

n.Is it possible for a hermaphrodite species to carry out cross-fertilization?

o.What is direct development? Do planaria have a larval stage?

p.Into which classes are platyhelminthes divided? How can these classes be described and what are some representative species in each of them?

q.What are the main human diseases caused by platyhelminthes?

Global Warming: Carbon Dioxide and its Effects on Agriculture Many scientists understand that earth is getting warmer and that the cause could be an intensified greenhouse effect resulting from increased CO2 emissions from industry, vehicles, and the burning of forests. Increased carbon dioxide levels will also affect the nutritional quality of many crop plants by decreasing protein content and increasing weed growth. Global warming could influence agriculture and perhaps even completely melt polar ice, leading to flooding of coastal regions. Over 90% of scientists now agree that global warming is occurring. In response to this potential threat, several European countries, the United States, Australia, and New Zealand have made a commitment to significantly reduce carbon dioxide emissions. However, some countries oppose taking strong actions at this time and the U.S. has only met a relatively small proportion of its commitments. Several reasons are cited. First, some experts think the apparent warming trend may be just a random fluctuation in temperature. Second, if the temperature increase is real, some argue that it has yet to be proven that the cause is increased CO2. However, regardless of the effects on climate change, the carbon fertilization effect of increased CO2 levels is affecting crops each year. Some believe it would be difficult to cut CO2 emissions without sacrificing comfort, convenience, and economic growth. Carbon Dioxide as a Greenhouse Gas: http://www.epa.gov/climatechange/ghgemissions/gases/co2.html Effects of Carbon Fertilization of Crop Plants: http://www.news.ucdavis.edu/search/news_detail.lasso?id=9479 http://news.illinois.edu/news/14/0507CO2_AndrewLeakey.html http://news.heartland.org/newspaper-article/2013/10/29/carbon-dioxide-emissions-stimulating-15-trillion-crop-production Please consider and reply to the questions below: Do you think we should have more evidence that greenhouse warming is real before taking action? Or is it better to play it safe and act now to reduce CO2 emissions? The evidence of carbon fertilization of crop plants is readily available and accepted. Crop plants are producing less seed and less protein. Weed plants are overgrowing crop plants and reducing annual yields. Should we take action now to reduce CO2 emissions in order to prevent the loss of agricultural output and nutritious crops?

aquamarinealligator170

1. CAN BE MORE THAN ONE The arthropods are the most successfulgroup of animals; several key features explain their success. Checkall of the features that one would use to classify members intothis phylum.

growth takes place throughecdysis

a rigid exoskeleton made ofchitin

closed circulatory systems

jointed appendages

a rigid exoskeleton made ofkeratin

segments specialized intofunctional tagmata
2. An entomologist observed a locust sitting on a branch pumpingits abdomen like an accordion. What is the insect doing?

Stretching out its pedipalps

Assisting gas exchange in thetracheal system

Speeding the flow of blood throughits veins and arteries

Clearing its spinnerets

3.Dibenzoylhydrazines are a category of molecules that have beenused as insecticides. They work by blocking ecdysteroid receptors.How does this kill an insect?

The chitinous exoskeleton isdissolved.

The insect can no longer excretenitrogenous wastes.

The insect can no longer coordinateits movements.

The insect cannot molt.

4. The grasshopper equivalent of an ear is found

on the side of its head.

on the abdomen.

Grasshoppers do not have afunctional equivalent to ears.

directly behind the antennae.

5. A snail in your garden and an oyster are quite different inappearance. What would be evidence to justify grouping themtogether?

Both have a mantle capable ofsecreting calcium carbonate.

Both use siphons to obtainoxygen.

Both have sensory antenna.

Both use a radula for feeding.

6.Barnacles are sessile filter feeders but unlike bivalves theyhave internal fertilization. How do they solve this problem?

They are only capable of asexualreproduction.

The filter sperm from the watercolumn.

They are hemaphrodites withespecially long penises.

They get fertilized during free living larval stages.

7. Bivalves lack a radula. How dothey eat?

The gills filter water and extractorganic matter.

The mantle traps and moves sedimentto the stomach for digestion.

Inhalent siphons suck water intothe mouth.

Most bivalves have photosynthetic endosymbionts in the visceralmass.

8.If a marine biology student discovered a dorsoventrallyflattened marine worm, what would be an effective way to determineif the specimen was a flatworm or a ribbon worm?

Examine the morphology of theexcretory system.

Look for a head at the anteriorend.

Determine the number of embryonicmembranes.

Look for an anus.

9.Inside its beak an octopus has a rasping tongue that is usedto tear apart food, which gastropod structure is this analogousto?

Nephridium

Radula

Shell

Mantle

10.Pinworm is spread by contact, and the worms cause severeitching around the anus. Why is it so common?

Insect vectors spread thedisease.

The intense itch produces anintense desire to scratch.