Curriculum Map 94 - BIOLOGY JUNCTION

Ecology

Ecology

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Ecology is the study of interactions between organisms (biotic part) and their nonliving environment (abiotic factors)

Biotic factors includes plants, animals, fungi, & microorganisms. They may be producers, consumers, or decomposers.

Abiotic factors include climate, soil, temperature, water, air, sunlight, humidity, pH, and atmospheric gases.

Habitat is the place a plant or animal lives, while its niche is its total way of life.

Life is organized into levels:

Organism (any single living thing)

Population (members of the same species living in one place)

Community (all the populations living in an area)

Ecosystem (community living in a similar habitat such as a forest)

Biomes (ecosystems covering wide areas & with similar climates & organisms)

Biosphere ( all the living & nonliving things on earth)

Producers:

	Make their own food through photosynthesis or chemosynthesis
	Includes plants, algal protists, & some bacteria

Consumers:

	Can’t make their own food
	May be herbivores (feed only on plants), carnivores (feed only on animals), or omnivores (feed on plants & animals)

Decomposers:

	Break down dead plants & animals (detritus)
	Recycle nutrients
	Called detritivores
	Include fungi & bacteria

Sunlight is the ultimate energy for all life on earth, but only producers can get their energy directly from the sun.

Energyflowinecosystemimage

Trophic levels are feeding levels of producers & consumers in an ecosystem:

	1st Trophic Level is producers that use sunlight directly
	2nd Trophic Level includes herbivores that feed directly on plants
	Higher Trophic Levels are carnivores feeding on each other

energypyramid

Food chains & food webs:

	Chains show who eats whom in an ecosystem.
	Webs are made up of several food chains.
	Always begin with producers absorbing sunlight.
	Producers store energy in the chemical bonds of the food they make.
	Stored energy is passed to consumers when they eat producers or other consumers.
	Some energy is lost at each trophic level as heat when consumers “burn” food during cellular respiration.
	Both energy & nutrients must move through an ecosystem.

Three main elements that must move through an ecosystem:

	Water
	Carbon
	Nitrogen

Water or Hydrologic Cycle:

	Cells are 70 – 90% water
	Water is needed for metabolic processes
	Water is most important for terrestrial organisms because of desiccation (drying out)

Steps in the water Cycle:

Evaporation Transpiration
(water loss from lakes, rivers, oceans…) (water loss from plant leaves)

¯ ¯

Condensation
(water vapor forms clouds)

Precipitation
(water returns to earth as sleet, rain, snow…)

Surface Runoff
(returns water to bodies of water or to groundwater)

Carbon Cycle:

	Consists of photosynthesis, cellular respiration, & decomposition
	Begins with producers taking carbon dioxide from the air during photosynthesis
	Carbon dioxide used in cellular respiration
	Decomposing plants and animals return Carbon to the soil

Carbon Cycle Steps:

Plant leaves take carbon dioxide from air

Plants store carbon in carbohydrates or starches
(photosynthesis)

Plants & animals release carbon dioxide back into the air
(cellular respiration)

Decomposers return carbon to environment
(decomposition)

Nitrogen:

	Needed by all organisms
	Used to make proteins & nucleic acids (DNA & RNA)
	Air made up of 80% nitrogen
	Only Cyanobacteria & Rhizobium bacteria can use nitrogen directly from the air (nitrogen fixation)
	Bacteria found in the soil & on the roots of legumes (beans, peas …)

Steps in the Nitrogen Cycle:

Cyanobacteria & Rhizobium take nitrogen from air
(nitrogen fixation)

Convert nitrogen gas into ammonia

Nitrifying bacteria in soil change ammonia into nitrates

Plants can absorb & use nitrates to make proteins

Consumers eat plants & get proteins containing nitrogen

Decomposers break down dead organisms & return nitrogen to air
(called ammonification)

Anaerobic bacteria in soil release nitrogen from nitrates into air
(called denitrification)

Three main types of ecosystems:

	Terrestrial (land)
	Freshwater (rivers, ponds, lakes …)
	Marine (oceans & seas)

Terrestrial ecosystems are divided into 7 biomes with similar climates & organisms

Seven Terrestrial Biomes:

	Tropical Rain Forest (jungle)
	Savanna (tropical grasslands)
	Deserts
	Grasslands
	Deciduous Forest
	Taiga (coniferous forest)
	Tundra

Tundra:

	Cold & dark most of the year
	Includes the arctic
	Permafrost is the top layer of soil that thaws & in which plants grow
	No trees, but sedges & grass, mosses, & lichens
	Many migratory animals
	Lemmings & ptarmigans are year round residents
	Approximately 20 cm annual rainfall

Tundra

Taiga:

Coniferous forest
Extends across northern Eurasia & North America
Contains conifers or evergreens (spruce, cedar, fir, pine …)
Needle like leaves withstand weight of snow
Bear, deer, moose, wolves, mountain lions …
Sequoia or redwood (largest conifer) grows here
Bristle cone pine oldest living conifer found here

Coniferous Forest

Temperate Deciduous Forest:

South of taiga in North America, eastern Asia, & Europe
High annual rainfall (75-150 cm)
Moderate temperatures
Well-defined seasons of about equal length
Trees loose leaves in winter (deciduous)
Show stratification (plant layers):
1. Canopy – broad leaf deciduous trees forming uppermost layer
2. Under story – shrubs
3. Forest Floor – herbaceous plants
Songbirds, deer, rabbits, foxes, squirrels, frogs 7 toads, lizards …

Temperate Deciduous Forest

Tropical Rain forest:

Near equator
Warm climate (20 -25 degrees C)
Plentiful rainfall (190 cm/year)
Contains the greatest diversity of plants & animals
Insects, monkeys & apes, snakes, tropical birds, leopards…
Animals & plants brightly colored
Poor soil for agriculture

Rainforest

Grasslands:

Mostly grasses with a few trees due to less rainfall
Moderate climates
Good for agricultural crops
Grazing & burrowing animals dominate
Also called prairies

Grassland

Savanna:

Tropical grasslands
Warm climate & rainy season
Antelope, zebra, lions, wildebeests, hyenas, elephants…
Suffer from floods & drought

(26KB)

Deserts:

Low annual rainfall
Subject to strong winds
Days usually hot & nights cold
Sahara desert is without vegetation
Succulents such as cacti & other water storing plants
Most animals nocturnal
Lizards, snakes, roadrunners, insects, tarantula, hawks, rodents, coyotes…

Desert

Aquatic Biomes:

May be freshwater or saltwater
Wetlands near oceans have brackish water (mixture of fresh & salt waters)
Part of the part water or hydrologic cycle
Often polluted by man’s activities

Lakes & Rivers:

Freshwater
Oligotrophic lakes are nutrient poor (catfish, carp…)
Eutrophic lake are nutrient rich (trout, bass…)
Deep lakes have layers or strata where different plants & animals live
Phototropic organisms in upper layers for light
Estuary at mouth of river contains brackish water

Ocean Zones:

Intertidal zone
1. Along shoreline
2. Wave action
3. Lots of light so many producers
4. Starfish, sand dollars…
Neritic Zone
1. Ocean water above continental shelf
2. Coral reef found here
3. Surrounds continents & receives light in upper layers
Oceanic Zone
1. Beyond continental shelf
2. Deepest area (up to 7 miles)
3. Bottom doesn’t receive light so animals adapted to darkness (many produce their own light, feed on other animals…)
4. Deepest area called abyss
5. Upper area gets light & called the photic zone (lots of seaweed here)
6. Floaters called plankton (microscopic organisms)
7. Swimmers such as fish called nekton
8. Bottom dwellers called benthos

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Introduction:
In this exercise you will measure diffusion of small molecules through dialysis tubing, an example of a semi permeable membrane. The movement of a solute through a semi permeable membrane is called dialysis. The size of the minute pores in the dialysis tubing determines which substance can pass through the membrane. A solution of glucose and starch will be placed inside a bag of dialysis tubing. Distilled water will be placed in a beaker, outside the dialysis bag. After 30 minutes have passed, the solution inside the dialysis tubing and the solution in the beaker will be tested for glucose and starch. The presence of reducing sugars like glucose, fructose, and sucrose will be tested with Benedict’s Solution. The presence of starch will be tested with Lugol’s solution (iodine-potassium-iodide).

Procedure:

Obtain a 30 -cm piece of 2.5-cm dialysis tubing that has been soaking in water. Tie off one end of the tubing to form a bag. To open the other end of the bag, rub the end between your fingers until the edges separate.
Place 15 mL of the 15% glucose/ 1% starch solution in the bag. Tie off the other end of the bag, leaving sufficient space for the expansion of the bag’s contents. Record the color of the solution in Table 1.1.
Test the 15% glucose / 1% starch solution in the bag for the presence of glucose. Your teacher may have you do a Benedict’s test. Record the results in Table1.1.
Fill a 250 mL beaker or cup 2/3 full with distilled water. Add approximately 4 mL of Lugol’s solution to the distilled water and record the color in Table 1.1. Test the solution for glucose and record the results in Table 1.1.
Immerse the bag in the beaker of solution.
Allow your set up to stand for approximately 30 minutes or you see a distinct color change in the bag or the beaker. Record the final color of the solution in the bag, and of the solution in the beaker, in Table 1.1.
Test the liquid in the beaker and in the bag for the presence of glucose. Record the results in Table 1.1.

Table 1.1

	Initial Contents	Initial Solution Color	Final Solution Color	Initial Presence of Glucose	Final Presence of Glucose
Bag	15% Glucose & 1% starch
Beaker	H2O + IKI

Analysis of Results:
1. Which substance(s) are entering the bag and which are leaving the bag? What experimental evidence supports your answer?

_______________________________________________________________________

2. Explain the results you obtained. Include the concentration differences and membrane pore size in your discussion.

________________________________________________________________________

3. Quantitative data uses numbers to measure observed changes. How could this experiment be modified so that quantitative data could be collected to show that water diffused into the dialysis bag?

________________________________________________________________________

4. Based on your observations, rank the following by relative size, beginning with the smallest : glucose molecules, water molecules, IKI molecules, membrane pores, starch molecules.

_______________________________________________________________________

5. What results would you expect if the experiment started with glucose and IKI solution inside the bag and only starch and water outside? Why?

________________________________________________________________________

Osmosis:
In this experiment you will use dialysis tubing to investigate the relationship between solute concentration and the movement of water through a semi permeable membrane by the process of osmosis. When two solutions have the same concentration of solutes, they are said to be isotonic to each other. If the two solutions are separated by a semi permeable membrane, water will move between the two solutions, but there will be no net change in the amount of water in either solution. If two solutions differ in the concentration of solutes that each has, the one with more solute hypertonic to the one with the less solute. The solution that has less solute is hypotonic to the one with more solute. These words can only be used to compare solutions.

Procedure:
1. Obtain six 30-cm strips of presoaked dialysis tubing.

2. Tie a knot in one end of each piece of dialysis tubing to form six bags. Pour approximately 25 mL of each of the following solutions into separate bags:

Distilled water
0.2 M sucrose
0.4 M sucrose
0.6 M sucrose
0.8 M sucrose
1.0 m sucrose

Remove most of the air from the bags by drawing the dialysis bag between two fingers. Tie off the other end of the bag. Leave sufficient space for the expansion of the contents in the bag.

3. Rinse each bag gently with distilled water to remove any sucrose spilled during filling.

4. Carefully blot the outside of each bag and record in Table 1.2 the initial mass of each bag.

5. Fill six 250 mL beakers 2/3 full with distilled water.

6. Immerse each bag in one of the beakers of distilled water and label the beaker to indicate the molarity of the solution in the dialysis bag. Be sure to completely submerge each bag.

7. Let them stand for 30 minutes.

8. At the end of 30 minutes remove the bags from the water. Carefully blot and determine the mass of each bag.

9. Record your group’s results in Table 1.2. Obtain data from the other lab groups in your class to complete Table 1.3: Class Data.

Table 1.2 Dialysis Bag Results: Individual Data

Contents in Dialysis Bag	Initial Mass	Final Mass	Mass Difference	% Change in Mass
a). Distilled Water
b). 0.2 M
c). 0.4 M
d). 0.6 M
e). 0.8 M
f). 1.0 M

To Calculate:

% change in mass

Final Mass-Initial Mass

100

———————–

Initial Mass

Table 1.3 Dialysis Bag Results: Class Data

percent change in Mass of Dialysis Bags

Bag Contents	Group 1	Group 2	Group 3	Group 4	Group 5	Group 6	Total	Class Average
Distilled Water
0.2 M
0.4 M
0.6 m
0.8 M
1.0 M

10. Graph the results for both your individual data and class average on the following graph. For this graph you will need to determine the following:

a). the independent variable. __________________________________

b). the dependent variable. ___________________________________

Graph Title ______________________________________________

Analysis of Results:
1. Explain the relationship between the change in mass and the molarity of sucrose within the dialysis bag.

________________________________________________________________________

2. Predict what would happen to the mass of each bag in this experiment if all the bags were placed in a 0.4 M sucrose solution instead of distilled water. Explain your response.

________________________________________________________________________

3. Why did you calculate the per cent change in mass rather than using the change in mass?

________________________________________________________________________

4. A dialysis bag is filled with distilled water and then placed in a sucrose solution. The bag’s initial mass is 20 g. and its final mass is 18 g. Calculate the percent change of mass, showing your calculations in the space below.

5. The sucrose solution in the beaker would have been ___________________ to the distilled water in the bag.

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DNA Quiz

DNA QUIZ QUESTIONS

1. What is the general name for chemicals like DNA and RNA
2. What general shape does the DNA molecule have?
3. List 4 differences between RNA and DNA
4. Describe the function of the mRNA in Protein Synthesis
5. What is the definition of a codon
6. What is the definition of an anti-codon
7. How many amino acids will result from the following strand of DNA?
A C G C C C A A A T A C
8. Name the two stages that make up protein synthesis
9. Where in the cell does replication take place?
10. Describe the function of the tRNA in Protein Synthesis?
11. Describe briefly the events that occur during transcription?
12. Name 2 common environmental mutagens
13. Describe briefly the events that occur during translation?
14. What is the definition of a) translation b) transcription
16. Define complementary base pairing and give an example?
17. Describe the function of the ribosome during protein synthesis
18. From a given strand of DNA. Show the results of Transcription or Replication
19. Make a drawing of DNA or RNA nucleotide and label the parts
20. Give 2 examples of a) purines b) pyrimidines
21. Name the 4 bases that make up DNA or RNA molecules
22. Describe how an environmental mutagen could cause a mutation
23. Describe briefly the events that occur during replication?
24. List 3 functions of DNA
25. Describe the function of the DNA in Protein Synthesis
26. What is the definition of a chromosomal mutation
27. What is the definition of a gene mutation
28. If the Nucleic acids are like ladders: What chemicals form the backbone of DNA or RNA molecules?
29. If the Nucleic acids are like ladders: What chemicals form the rungs of DNA or RNA molecule?
30. Briefly describe what occurs during Protein synthesis

31. What is recombinanant DNA. Give two uses of recombinant DNA

DNA SUBJECTIVE QUESTIONS
1. Describe 2 differences between the following pairs of terms
a. codon and anti codon b. replication and transcription c. RNA and DNA

d. transcription and translation e. chromosomal and gene mutation f. mRNA and tRNA

g. purine and pyrimidine h. complementary base pairing and joining of adjacent nucleotides
2. Describe complementary base pairing. Show an example.

3. Explain the roles/function of the following during Protein Synthesis:
a. DNA in the nucleus b. Transfer RNA (tRNA) c. Messenger RNA (mRNA) d. Ribosome
4. Name 2 environmental mutagens and describe how they could cause a mutation in an organism

5. Explain the process of DNA replication

6. Make a drawing of an RNA or DNA nucleotide and label the parts

7. Compare DNA and RNA with respect to the following things:
a. shape b. chemical makeup c. function d. abundance in the cell

8. Explain the process of translation

9. Explain the process of transcription

10. Describe in sequence, the process of protein synthesis. Include in your answer the names of the various steps, the organelles involved, and the names of the major molecules.

11. Describe how radiation or another such substance could cause mutations to occur.

12. From a given strand of DNA be able to determine the sequence of mRNA codons, and the amino acid strand produced.

Ecology Study Guide

Ecology Study Guide

List several biotic factors in an ecosystem.

List several abiotic factors in an ecosystem.

What serves as the ultimate energy for all life on earth?

What is transpiration & what cycle is it a part of ?

Why are the Rhizobium bacteria beneficial to plants?

What is nitrogen fixation?

What is denitrification?

Where is the intertidal zone found & list several organisms that would be found there?

Name 3 types of consumers based on their eating habits.

What is detritus & why is it important?

What are trophic levels & give an example?

What is the term for an organism’s total way of life?

How does an animal’s habitat differ from its niche?

Compare & contrast biomes.

Describe estuaries.

How does an oligotrophic lake differ from a eutrophic lake?

What is brackish water & where would it be found?

Where is the neritic zone found & what organisms would be found there?

Where would benthos organisms be found? Give an example of such a dweller.

Describe abiotic & biotic factors for each of these biomes:

Tropical rain forest

Taiga

Tundra

Grassland

Savanna

Desert

Deciduous forest

Intertidal Zone

Neritic Zone

Oceanic Zone

Oligotrophic River

Eutrophic River

Estuary

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Category: Curriculum Map

DNA Patterns

Ecology

Diffusion and Osmosis

DNA Quiz

Ecology Study Guide