Category: Curriculum Map

DNA Code for Insulin

 

DNA’s Instructions for Insulin  

 

Introduction:

Below are two partial sequences of DNA bases (shown for only one strand of DNA)  Sequence 1 is from a human and sequence 2 is from a cow.  In both humans and cows, this sequence is part of a set of instructions for controlling the production of a protein.  In this case, the sequence contains the gene to make the protein insulin.  Insulin is necessary for the uptake of sugar from the blood.  Without insulin, a person cannot use digest sugars the same way others can, and they have a disease called diabetes.

Materials:

paper, pencil, codon table

Procedure:

  1. Using the DNA sequence given in table 1, make a complimentary RNA strand for  the human.  Write the RNA directly below the DNA strand (remember to substitute U’s for T’s in RNA).
  2. Repeat step 1 for the cow.  Write the RNA directly below the DNA strand in table 2.
  3. Use the codon table in your book to determine what amino acids are assembled to make the insulin protein in both the cow and the human.   Write your amino acid chain directly below the RNA sequence.

Table 1 

 

Sequence 1 ­ Human
DNA C C A T A G C A C G T T A C A A C G T G A A G G T A A
RNA
Amino Acids

 

Table 2

Sequence 1 ­ Cow
DNA C C G T A G C A T G T T A C A A C G C G A A G G C A C
RNA
Amino Acids

Analysis:

1. The DNA sequence is different for the cow and the human, but the amino acid chain produced by the sequence is almost the same.  How can this happen?

 

 

2. Diabetes is a disease characterized by the inability to break down sugars. Often a person with diabetes has a defective DNA sequence that codes for the making of the insulin protein. Suppose a person has a mutation in their DNA, and the first triplet for the gene coding for insulin is C C C  (instead of C C A).   Determine what amino acid the new DNA triplet codes for.    Will this person be diabetic?

 

3. What if the first triplet was C A A ?

 

4. How is it that a code consisting of only four letters, as in DNA ( A, T, G, C ) can specify all the different parts of an organism and account for all the diversity of organisms on this planet?

 

 

DNA sequences are often used to determine relationships between organisms.  DNA sequences that code for a particular gene can vary widely.  Organisms that are closely related will have sequences that are similar. Below is a list of sequences for a few organisms:

 

Human CCA   TAG   CAC   CTA
Pig CCA   TGG   AAA   CGA
Chimpanzee CCA   TAA   CAC   CTA
Cricket CCT   AAA   GGG   ACG

 

5. Based on the sequences, which two organisms are most  closely related?

 

6. An unknown organism is found in the forest, and the gene is sequenced, and found to be   C C A  T G G  A A T  C G A  ,  what kind of animal do you think this is?

 

 

Echinoderm Study Guide B1

Echinoderm Study Guide

 

Know the answers to the following:

 

A water vascular system is a trait of?
Clams are the basic food for what echinoderm?
A sea star feeds by extending what?
A sea star’s endoskeleton is made of what type of plates?
What around the mouth of a starfish helps coordinate its movements?
Tube feet  are part of what echinoderm system?
The blastopore becomes the anus in what type of organism?
Are chordates & echinoderms protostomes or deuterostomes?
Echinoderms like the sea urchin have what type of symmetry?
Are echinoderms fast or slow moving organisms?
How do echinoderms move?
Echinoderm larva have what type of symmetry?
What are the muscular sacs that force water through the water vascular system called?
In what phylum are sea squirts or tunicates?
Tunicates have a leathery what?
What animals are in the class Ophiuroidea?
How do basket stars & brittle stars differ?
What is the purpose of spines on a brittle stars arms?
Name an adult echinoderm with bilateral symmetry.
Do humans have a tail at any point during their development?
What was the function of gill slits in early chordates?
What is the flexible tube below the nerve cord in chordates called?
Where are lancelets usually found?

Be able to label the parts of the water vascular system of a starfish.

DNA Replication Lab

Modeling DNA Replication

 

Introduction

Within the nucleus of every cell are long strings of DNA, the code that holds all the information needed to make and control every cell within a living organism. DNA, which stands for deoxyribonucleic acid, resembles a long, spiraling ladder. It consists of just a few kinds of atoms: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Combinations of these atoms form the sugar-phosphate backbone of the DNA — the sides of the ladder, in other words.

Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung — one for each side of the ladder.) A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide. Nucleotides are abundant in the cell’s nucleus. Nucleotides are the units which, when linked sugar to phosphate, make up one side of a DNA ladder.

During DNA replication, special enzymes move up along the DNA ladder, unzipping the molecule as it moves along. New nucleotides move in to each side of the unzipped ladder. The bases on these nucleotides are very particular about what they connect to. When the enzyme has passed the end of the DNA, two identical molecules of DNA are left behind. Cytosine (C) will “pair” to guanine (G), and adenine (A) will “pair” to thymine (T). How the bases are arranged in the DNA is what determines the genetic code.

 

When the enzyme has passed the end of the DNA, two identical molecules of DNA are left behind. Each contains one side of the original DNA and one side made of “new” nucleotides. It is possible that mistakes were made along the way — in other words, that a base pair in one DNA molecule doesn’t match the corresponding pair in the other molecule. On average, one mistake may exist in every billion base pairs. That’s the same as typing out the entire Encyclopedia Britannica five times and typing in a wrong letter only once!

Objectives

The replication of DNA before cell division can be shown using paper templates for the components of DNA nucleotides.

Materials

  • Cut Outs of basic subunits of DNA
  • Colors or markers
  • Scissors
  • Tape or glue
  • Paper & pencil

Procedure:

  1. Cut out all of the units needed to make the nucleotides from the handout provided.
  2. Color code the Nitrogenous bases, phosphorus, and deoxyribose sugar as follows —
    Adenine = red, Guanine = green, Thymine = yellow, Cytosine = blue, Phosphate = brown, and Deoxyribose = purple.
  3. Using the small squares and stars as guides, line up the bases, phosphates and sugars.
  4. Now glue the appropriate parts together forming nucleotides.
  5. Construct DNA model using the following sequence to form a row from top to bottom – cytosine (topmost), thymine, guanine, and adenine (bottommost).
  6. Let this arrangement represent the left half of your DNA molecule.
  7. Complete the right side of the ladder by adding the complementary bases. You will have to turn them upside down in order to make them fit.
  8. Your finished model should look like a ladder.
  9. To show replication, separate the left side from the right side, leaving a space of about 6-8 inches.
  10. Use the remaining nucleotides to complete the molecule using the left side as the base.
  11. Build a second DNA model by adding new nucleotides to the right half of the original piece of the molecule.
  12. Tape the nucleotides together to form 2 complete DNA ladders.

Questions

1. Of the 4 bases, which other base does adenine most closely resemble?

2. List the 4 different nucleotides.

3. Which 2 molecules of a nucleotide form the sides of a DNA ladder?

4. If 30% of a DNA molecule is Adenine, what percent is Cytosine?

5. What does the term replication mean?

6. What is another name for adenine and three phosphate molecules attached to it?

 

 

 

Dichotomous Keying

 

Dichotomous Keying

Introduction to Dichotomous Key Maker:

The identification of biological organisms can be greatly simplified using tools such as dichotomous keys.  A dichotomous key maker is an organized set of couplets of mutually exclusive characteristics of biological organisms.  You simply compare the characteristics of an unknown organism against an appropriate dichotomous key.  These keys will begin with general characteristics and lead to couplets indicating progressively specific characteristics. If the organism falls into one category, you go to the next indicated couplet.  By following the key and making the correct choices, you should be able to identify your specimen to the indicated taxonomic level.

Couplets can be organized in several forms.  The couplets can be presented using numbers (numeric) or using letters (alphabetical).  The couplets can be presented together or grouped by relationships.  There is no apparent uniformity in presentation for dichotomous keys.

Sample keys to some common beans used in the kitchen:

Numeric key with couplets presented together.  The major advantage of this method of presentation is that both characteristics in a couple can be evaluated and compared very easily.

 

 

 

 

1a. Bean round Garbanzo bean
1b. Bean elliptical or oblong Go to 2
2a. Bean white White northern
2b. Bean has dark pigments Go to 3
3a. Bean evenly pigmented Go to 4
3b. Bean pigmentation mottled Pinto bean
4a. Bean black Black bean
4b. Bean reddish-brown Kidney bean

 

Alphabetical key with couplets grouped by relationship.  This key uses the same couplet choices as the key above.  The choices within the first and succeeding couplets are separated to preserve the relationships between the characteristics.

 

 

A. Bean elliptical or oblong Go to B
   B.  Bean has dark pigments Go to C
            C.  Bean color is solid Go to D
            C.  Bean color is mottled Pinto bean
                     D.  Bean is black Black bean
                     D.  Bean is reddish-brown Kidney bean
   B.  Bean is white White northern
A. Bean is round Garbanzo bean

 

Rules for Using Dichotomous Keys: 

When you follow a dichotomous key, your task becomes simpler if you adhere to a few simple rules of thumb:

  1. Read both choices in a couplet carefully.  Although the first description may seem to fit your sample, the second may apply even better.
  2. Keep notes telling what sequence of identification steps you took.  This will allow you to double-check your work later and indicate sources of mistakes, if they have been made.
  3. If you are unsure of which choice to make in a couplet, follow both forks (one at a time).  After working through a couple of more couplets, it may become apparent that one fork does not fit your sample at all.
  4. Work with more than one sample if at all possible.  This will allow you to tell whether the one you are looking at is typical or atypical.  This is especially true when working with plants – examine more than one leaf, branch, cone, seed, flower,…etc.
  5. When you have keyed out an organism, do not take your effort as the final result.  Double check your identification scheme, using your notes.  Find a type specimen (if available) and compare your unknown to the type specimen.  If a type specimen is unavailable, find a good description of the indicated taxonomic group and see if your unknown reflects this description.
  6. When reading a couplet, make sure you understand all of the terms used.  The best keys will have a glossary of technical terms used in the key.  If a glossary is unavailable, find a good reference work for the field (textbook, biological dictionary,…etc.) to help you understand the term.
  7. When a measurement is indicated, make sure that you take the measurement using a calibrated scale.  Do not “eyeball” it or take a guess.

Exercise 1:

Using a container of beans, use one of the dichotomous keys above to identify the beans.  Glue the beans to the card provided and label them with their common name. Indicate what steps you followed to arrive at your answer.  Turn the card in to your instructor.  Compare your answers to the instructor’s descriptions and type specimen.

Exercise 2:

Obtain samples of the snack chips provided.  Develop a dichotomous key to identify the snacks.  In your notebook, keep track of the characteristics you used to differentiate between the different snack families.  What are the values of the characteristic for each snack food?

Exercise 3:

Use the dichotomous key to conifers provided below to identify conifers.

A Key to Selected North American Native and Introduced Conifers

 

 

01a Leaves needle-like Go to 02
01b Leaves flattened and scale-like Go to 27
02a Leaves are in clusters Go to 03
02b Leaves are borne singly Go to 15
03a Two to five leaves in a cluster Go to 04  Genus Pinus
03b More than five leaves in a cluster Go to 14
04a Leaves mostly 5 in a cluster White Pine (Pinus strobus)
04b Leaves 2 or 3 in a cluster Go to 05
05a Leaves mostly 3 in a cluster Go to 06
05b Leaves mostly 2 in a cluster Go to 08
06a Leaves twisted, less than 5 inches long Pitch Pine (Pinus rigida)
06b Leaves straight, more than 5 inches long Go to 07
07a Leaves 5-10 inches long, cones very thorny Loblolly pine (Pinus taeda)
07b Leaves mostly over 10 inches long, cones unthorned Longleaf pine (Pinus palustris)
08a Leaves mostly longer than 3 inches Go to 09
08b Leaves mostly shorter than 3 inches Go to 11
09a Leaves rigid, bark grayish Black pine (Pinus nigra)
09b Leaves narrower than 1.6mm; bark reddish brown or brown Go to 10
10a Cones thornless, twigs brown Norway pine (Pinus resinosa)
10b Cones thorny, twigs whitish Shortleaf pine (Pinus echinata)
11a Leaves mostly wider than 1.5 mm Go to 12
11b Leaves mostly narrower than 1.5 mm Go to 13
12a Leaves mostly longer than 35 mm Mugho pine (Pinus mugo)
12b Leaves mostly shorter than 35 mm Jack pine (Pinus banksiana)
13a

Twigs whitened

 Virginia pine (Pinus virginiana)
13b Twigs not whitened Scotch pine (Pinus sylvestris)
14a Leaves deciduous, clusters of 20-40 Larch (Larix sp.)
14b Leaves persistent, stiff, and four sided True cedar (Cedrus sp.)
15a Needles short and sharp Giant Sequioa  (Sequioadendron giganteum)
15b Needles longer than 12 mm Go to 16
16a Tiny pegs on twigs Go to 17
16b No pegs on twigs Go to 22
17a Pegs square, needles sharp Go to 18 Genus Picea
17b Pegs round, needles flat and blunt Hemlock (Tsuga sp.)
18a Leaves dark green or yellow green Go to 19
18b Leaves blue-green Go to 20
19a Branchlets droop Norway spruce (Picea abies)
19b Branchlets do not droop Red spruce (Picea rubens)
20a Leaves at right angles to stems Blue spruce (Picea pungens)
20b

Leaves point forward

 Go to 21
21a Leaves about 12 mm long, seed cones 15-32 mm in length, crown narrow and pointed Black spruce (Picea mariana)
21b Leaves about 19 mm long, seed cones 50 mm in length, spire-like crown

White spruce (Picea glauca)
22a Buds large and pointed Douglas fir (Pseudotsuga sp.)
22b Buds small and rounded Go to 23
23a Terminal buds round and clustered True fir (Abies sp.)
23b Terminal buds not clustered Go to 24
24a Needles white underneath Go to 25
24b Needles green underneath Go to 26  Genus Taxus
25a Needles pointed

Redwood (Sequoia sempervirens)
25b Needles blunt Hemlock (Tsuga sp.)
26a Leaves 18 mm long or less with inconspicuous midrib American Yew (Taxus canadensis)
26b Leaves 25 mm long or more with conspicuous midrib Japanese Yew (Taxus cuspidata)
27a All leaves short and sharp Giant Sequioa  (Sequioadendron giganteum)
27b Some leaves not sharp Go to 28
28a Cones round Go to 29
28b Cones not round Go to 31
29a Cones soft and leathery Juniper (Juniperus sp.)
29b Cones woody Go to 30
30a Cones under 12 mm in diameter False cypress  (Chamaecyparis)
30b Cones over 12 mm in diameter Cypress (Cuppressus)
31a Cones resemble rosebuds White cedar or arbor vitae (Thuja)
31b Cones resemble duck bills Incense cedar (Calocedrus)

 

Conifers to Identify:

1. Name: 2. Name:

3. Name: 4. Name:

5. Name: 6. Name:


7. Name: 8. Name:


9. Name: 10. Name:


11. Name: 12. Name:


13. Name: 14. Name:


15. Name: 16. Name:

Photos Copyright Nearctica.com

Click here for correct answers to conifer key

 

Ecology

Ecology

All Materials © Cmassengale 

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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