Author: Biology Junction Team

Scientific Method & Hand Size Lab

 

 

Using the Scientific Method

 

Introduction:

Humans are classified as a separate species because of all the special characteristics that they possess. These characteristics are controlled by strands of DNA located deep inside their cells. This DNA contains the code for every protein that an organism has the ability to produce. These proteins combine with other chemicals, within the body, to produce the cells, tissues, organs, organ systems, and finally the organism itself. The appearance of these organs, such as the shape of ones nose, length of the fingers, or the color of the eyes is called the phenotype.

Even though humans contain hands with five fingers, two ears, or one nose, there are subtle differences that separate these organs from another. There are subtle differences in a person’s genes that allows for these different phenotypes. In this lab, we are going to observe some of these differences in phenotype. All human hands look pretty much alike, but there are genes on your chromosomes that code for the characteristics making up your hand. We are going to examine two of these characteristics (hand width and hand length) and try to determine why these phenotypic differences occurred.

Materials:

  • metric ruler (see end of lab)
  • pencil
  • calculator

Procedures:

Day 1

  1. Choose a partner and have them measure the length of your right hand in centimeters. (Measure from the tip of your middle finger to the beginning of your wrist as shown in figure 1.)  Record your measurements in Table 1.
  2. Now measure and record the length in centimeters of your partners hand.
  3. Have your partner measure the width of your right hand, straight across the palm, and record the data in Table 1. (see figure 1.)
  4. Now measure & record the width of your partner’s hand.

Figure 1.

 

Table 1

 

Group Data on Right Hand Width and Length
Student Name Length of Hand (cm) Width of Palm (cm)

 

  1. After the entire class has completed Table 1, record your group data on the Class Data Table at the front of the room
  2. Record the Class Data Table information on your lab sheet’s Table 2.

Table 2

Class Data on Right hand Width and Length (cm)

Class Period:
Student Gender
(M / F)		 Hand Length (cm) Hand Width (cm)
1. M / F
2. M / F
3. M / F
4. M / F
5. M / F
6. M / F
7. M / F
8. M / F
9. M / F
10. M / F
11. M / F
12. M / F
13. M / F
14. M / F
15. M / F
16. M / F
17. M / F
18. M / F
19. M / F
20. M / F
21. M / F
22. M / F
23. M / F
24. M / F

Click for Class Data Table

Day 2

  1. In order to form a more accurate conclusion, the collection of additional data is necessary. Using the Class

. The teacher has the option to include the data from all the classes running this experiment. Below find tables that will allow the tabulation of several classes of data.

 

Table 3: All Classes Hand Length

Measurement of Hand length in cm. # of Males # of Females Total # ( Male + Female )
1.—————— ——————– ——————- ——————
2.—————— ——————- ——————- ——————-
3.—————— ——————- ——————- ——————-
4.—————— ——————- ——————- ——————-
5.—————— ——————- ——————- ——————-
6.—————— ——————- ——————- ——————-
7.—————— ——————- ——————- ——————-
8.—————— ——————- ——————- ——————-
9.—————— ——————- ——————- ——————-

 

Table 4: All Classes Hand Width

Measurement of Hand width in cm. # of Males # of Females Total # ( Male + Female )
1.—————— ——————– ——————- ——————
2.—————— ——————- ——————- ——————-
3,—————- ——————- ——————- ——————-
4.—————— ——————- ——————- ——————-
5.—————— ——————- ——————- ——————-
6.—————— ——————- ——————- ——————-
7.—————— ——————- ——————- ——————-
8.—————— ——————- ——————- ——————-
9.—————— ——————- ——————- ——————-

 

Line Graph the data from Tables 3 and 4. and then answer the questions that follow. Use the measurements of the width and length as your independent variable and the number of times that measurement appeared as your dependent variable.

Graph Tile: ___________________________________________________________

 

 

 

Analysis:

1. Examine the above graph. What is the shape of the line for hand length? _____________

________________________________________________________________________

2. What is the most abundant measurement for hand length? __________________.

3. What is (are) the least abundant measurement(s)? _________________________.

4. If we are to assign letters to represent the various lengths, what value(s) would we assign to the dominant genotype (HH)? ________________; the recessive genotype (hh)? ___________, and he heterozygous genotype (Hh)? _________________.

5. What would be the phenotypic name for the ( HH ) genotype? ___________________.

6. What would be the phenotypic name for the ( Hh ) genotype? ___________________.

7. What would be the phenotypic name for the ( hh ) genotype? ____________________.

8. Examine the above graph. What is the shape of the line for hand width ? ____________

________________________________________________________________________

9. What is the most abundant measurement for hand width? __________________.

10. What is (are) the least abundant measurement(s)? _________________________.

11. If we are to assign letters to represent the various lengths, what value(s) would we assign to the dominant genotype (WW)? ________________; the recessive genotype (ww)? ___________, and he heterozygous genotype (Ww)? _________________.

12. What would be the phenotypic name for the ( WW ) genotype? __________________.

13. What would be the phenotypic name for the ( Ww ) genotype? ___________________.

14. What would be the phenotypic name for the ( ww ) genotype? ___________________.

15. Are there any similarities in the graph of the above two characteristics? ____________.

16. If so, what are they? ____________________________________________________

17. Are there any differences in the graph of the above two characteristics? ____________.

18. If so, what are they? ____________________________________________________

19. Is there a difference in the length and width of the male and female hand? ___________.

20. Does the gender of a person have an effect on the phenotype of a trait? _____________.

Explain _________________________________________________________________

_______________________________________________________________________

________________________________________________________________________

 

Cut and use:

________________________________________________________________________

 

Unsegmented Worms Study Guide B1

Unsegmented Worm Study Guide

  • Describe the digestive tract of planarians
  • How are tapeworms able to get their food
  • What is the life style of most flatworms
  • What are the characteristics of rotifers
  • What are the general characteristics of all flatworms
  • Why do flatworms not need circulatory & respiratory systems
  • What causes schistosomiasis
  • To what kingdom & phylum do flatworms belong
  • Describe a pseudocoelom & give examples of worms that have this characteristic
  • Explain the life cycle of Ascaris
  • How do rotifers eliminate wastes
  • What is regeneration & give an example of an unsegmented worm that uses this process
  • What is the cuticle and what is its function
  • What are proglottids & what is their function
  • If a worm has a one-way digestive system, what must be true about the organism
  • Why are rotifers called “wheel animals”

Unsegmented Worm

Unsegmented Worms

All Materials © Cmassengale

Phylum Platyhelminthes
Characteristics

  • Called flatworms because bodies are flattened dorso-ventrally

  • Acoelomate – solid bodies without a lined body cavity
  • Have 3 body layers — outer ectoderm, middle mesoderm, & inner endoderm
  • Bilaterally symmetrical
  • Show cephalization (concentration of sensory organs at anterior or head end)
  • Body cells exchange oxygen & carbon dioxide directly with environment by diffusion
  • Single opening into gastrovascular cavity; two-way digestive tract
  • Some are parasites & others are free-living
  • Parasitic worms have thick cell layer called tegument covered with a nonliving cuticle covering their bodies as protection inside hosts
  • Includes 3 classes — Turbellaria (planarians), Trematoda (parasitic flukes), & Cestoda (parasitic tapeworms

Class Turbellaria

  • Most are marine but includes freshwater planarian (Dugesia)

Planarians

  • Spade-shaped at the anterior end & have two, light-sensitive eyespots
  • Can sense light, touch, taste, & small
  • Have 2 clusters of nerve cells or ganglia to form a simple brain
  • Nervous system composed of a nerve net
  • Capable of simple learning
  • Move by tiny hairs or cilia over a mucus layer that they secrete
  • Feed by scavenging or protozoans
  • Have a single opening or mouth located at the end of a muscular tube called the pharynx which can be extended when feeding
  • Flame cells help remove wastes to excretory pores

  • Hermaphrodites that cross-fertilize eggs that are then deposited into a capsule until hatching in 2-3 weeks
  • Reproduce asexually by fragmentation

Class Trematoda

  • Includes parasitic flukes
  • About 1 cm long & oval shaped

  • Require a host to live
  • Have both oral & ventral suckers to cling to host & suck blood, cells, & body fluids
  • Oral sucker around mouth at anterior end sucks blood
  • May be endoparasites (live inside a host) or ectoparasites (live on the outside of host
  • Covered in tough, unciliated tegument
  • Nervous & excretory systems like turbellarians
  • Hermaphrodites
  • Have a long, coiled uterus that stores & releases 10,000+ eggs
  • Eggs released through genital pore & develop into larva
  • Show complex life cycles
  • Life cycle of sheep liver fluke:
    * Adult liver flukes live in sheep liver & gall bladder where they mate & form eggs
    * Eggs enter intestines, pass out with feces, & hatch in water
    * Larva enter snails, asexually multiply, then leave snail & form cysts
    * Cysts (dormant larva with hard, protective covering) clings to grass
    * Sheep ingest cysts when they eat grass
    * Cysts hatch in digestive tract & bore through intestines into bloodstream
    * Mature & reproduce in the liver

  • Schistosomiasis (disease caused by parasitic blood flukes) infects people in Asia, Africa, & South America causing intestinal bleeding & tissue decay that can result in death

Class Cestoda

  • Includes tapeworms
  • Adapted for parasitic life
  • Tough outer tegument prevents being digested by host
  • Anterior end called scolex contains hooks & suckers for attachment to intestine of host

  • Long, ribbon-like bodies up to 12 m in length
  • Nervous system extends length of body but lacks sense organs
  • Lacks mouth & digestive tract but absorbs digested nutrients from host
  • Grows by making body segments called proglottids
  • Each proglottid produces eggs & sperm that cross-fertilize with other segments & also self-fertilize (hermaphrodites)
  • Oldest, mature proglottids containing eggs at posterior end break off & pass out with feces
  • Life cycle of beef tapeworm:
    * Cattle eat grass with proglottids containing fertilized eggs
    * Eggs hatch into larva & bore through cow’s intestine into bloodstream
    * Larva burrow into cow’s muscle & form cysts
    * Humans eat beef (muscle) & cysts travels to intestines
    * Cyst breaks open & adult beef tapeworm forms


BEEF TAPEWORM LIFE CYCLE

Phylum Nematoda
Characteristics

  • Called roundworms
  • Includes Ascaris, hookworms, Trichinella, & pinworms
  • Pseudocoelomates have fluid-filled body cavity partially lined with mesoderm
  • Pseudocoelom contains the body organs & provides hydrostatic skeletal support for muscles
  • Have long slender bodies that taper at both ends

  • Covered with flexible cuticle
  • Digestive tract with anterior mouth & posterior anus; called one-way digestive tract
  • Separate sexes in most species
  • Most are free living
  • Some are parasites on plants & animals
  • Ascaris is a parasitic roundworm living in the intestines of pigs, horses, & humans
  • Ascaris life cycle:
    * Enter body in contaminated food or water & hatch in intestines
    * Larva bore into bloodstream & carried to lungs & throat
    * Larva coughed up, swallowed, & return to intestines to mature & mate
    * Block the intestine causing death

  • Hookworm eggs hatch in moist soil & larva bore through bare feet of new host 
  • Trichinella are human parasites caused by eating undercooked pork containing the cysts
    * Cause disease called trichinosis
    * Cysts cause muscle pain & stiffness


 CYSTS IN CONTAMINATED PORK

Phylum Rotifera
Characteristics

  • Known as rotifers or wheel animals
  • Transparent, free-swimming microscopic animal
  • Freshwater & marine
  • Have a ring of cilia around mouth that rotates like a wheel to bring in food
  • Feed on unicellular algae, bacteria, & protozoa
  • Have a muscular organ called the mastax behind the pharynx to chop food
  • Nervous system composed of anterior ganglia & 2 long nerve cords
  • Show cephalization (head end)
  • Have 2 anterior, light-sensitive eyespots

Back

 

Toothpickase

Toothpick-ase: Introduction to Enzymes

    Enzymes are used in all metabolic reactions to control the rate of reactions and decrease the amount of energy necessary for the reaction to take place. Enzymes are specific for each reaction and are reusable. Enzymes have an area called the active site to which a specific substrate will bond temporarily while the reaction is taking place. Enzymes are proteins that are used as catalysts in biochemical reactions. A catalyst is a factor that controls the rate of a reaction without itself being used up. In biological systems, enzymes are used to speed up the rate of a reaction. However, there are a number of factors that can affect the rate of an enzyme-facilitated reaction, in addition to the presence of the enzyme, amongst them are:

  1. Substrate concentration
  2. Temperature

Here is a set of quick activities designed to simulate how substrate concentration and temperature affect enzyme function. In the activities that follow:

  • One person’s fingers are the enzyme TOOTHPICKASE
  • The toothpicks are the SUBSTRATE
  • Toothpickase is a DIGESTIVE ENZYME. It breaks down toothpicks into two units. To hydrolyse the toothpick, place a toothpick between the thumb and the first finger of each hand. Break the toothpick in two pieces.

Materials:
100 toothpicks per team
bowl
clock/watch with a second hand
Pencil

Procedure:

Part A – rate of Product Formation in an Enzyme-Facilitated reaction
In this activity, the toothpicks represent a substrate and your thumbs and index fingers represent the enzyme, toothpick-ase. When you break a toothpick, the place where the toothpick fits between your fingers represents the active site of the enzyme.

1. Count out 100 unbroken toothpicks into a bowl on your desk.

2. Have one person in the group serve as the timer, have one person serve as the recorder, and have another person in your group act as the enzyme or toothpick-ase.

3. The person acting as the enzyme is to break toothpicks without looking at the bowl and all of its products (broken toothpicks). All broken toothpicks must remain in the bowl along with the unbroken toothpicks, & you cannot re-break a broken toothpick!.

4. The experiment is conducted in 10 second intervals.

5. WITHOUT LOOKING AT THE BOWL, break as many toothpicks as you can in 10 second intervals and record this on the data table. Broken toothpicks should be kept in the bowl with unbroken toothpicks because products & reactants mix in metabolic reactions. DO NOT BREAK TOOTHPICKS ALREADY BROKEN! 

Remember when counting, two halves equal a whole broken toothpick! 

6. Do another 10 seconds of breaking (total of 20 seconds now), and then count & record the number of toothpicks broken.

7. Do another 10 seconds (thirty seconds total now) more of breaking and count and record the number of toothpicks broken.

8. Continue breaking toothpicks for these total time intervals ( 60, 120, and 180 seconds). REMEMBER TO ALWAYS THROW BROKEN TOOTHPICKS BACK IN THE PILE (because products & reactants stay mixed in reactions), BUT DON’T RE-BREAK THEM (the enzyme has already acted on the substrate!  

6. Graph the number of toothpicks broken as a function of time (10, 20, 30, 60, 120, & 180 seconds.) Be sure to title your graph and to label the x and y-axis.

Data Table:

 

Total Time (seconds) Number of toothpicks broken
10
20
(additional 10 seconds)
30
(additional 10 seconds)
60
(additional 30 seconds)
120
(additional 60 seconds)
180
(additional 60 seconds)

 

Graph Title: ____________________________________________________________

 

 

Materials:
1 box toothpicks per team
100 paper clips
clock/watch with a second hand
Pencil

PART B: EFFECT OF SUBSTRATE CONCENTRATION ON REACTION RATE

 

  1. Remove the broken toothpicks from the shallow bowl. Place 100 paperclips in the empty bowl. The paper clips represent a “solvent” in which the toothpicks are “dissolved”. Different concentrations are simulated by mixing different numbers of toothpicks in with the paper clips.
  2. For the first trial, place 10 toothpicks in the bowl with the paper clip. Mix them up. The enzyme has 20 seconds to react (break as many toothpicks as possible). Remember the enzyme breaks the toothpicks without looking at the bowl and all of the products (“broken toothpicks”) must remain in the bowl. Remember toothpicks can only be digested once; do not break toothpicks already broken! Record the number broken at a concentration of 10.
  3. Remove the broken toothpicks and repeat with concentrations of 20, 30, 40, 50, 60, 70, 80, 90, and 100 toothpicks, each time mixing them with the 100 paper clips.
  4. Graph the results.
  5. Discuss your results and explain why the rates were different at different concentrations. Summarize the effect of substrate concentration on enzyme action.

Discussion & summary:

 

 

 

Data Table:

 

Time (seconds) Toothpick Concentration Number of toothpicks broken
20 10
20 20
20 30
20 40
20 50
20 60
20 70
20 80
20 90
20 100

 

Graph Title: ____________________________________________________________

 

 

Materials:
10 toothpicks per team
ice & ice bucket
clock/watch with a second hand
Pencil

PART C: EFFECT OF TEMPERATURE SUBSTRATE CONCENTRATION ON REACTION RATE

 

  1. Select 10 toothpicks. Time how long it takes to break the 10 toothpicks as fast as you can.
  2. Place your hands in the pail of iced water for 10 minutes. Repeat step 1.
  3. Calculate the rate of enzyme action in toothpicks per second. Compare the two rates.
  4. Discuss your results and explain why the rates were different at different temperatures. Summarize the effect of temperature on enzyme action.

Discussion & summary: 

 

 

 

 

Analysis & conclusions:

1.What happens to the reaction rate as the supply of toothpicks runs out?

 

 

2. What would happen to the reaction rate if the toothpicks were spread out so that the “breaker” has to reach for them?

 

3. What would happen to the reaction rate if more toothpicks (substrate) were added?

 

4. What would happen to the reaction rate if there were two “breakers” (more enzymes)?

 

5. What happens if the breaker wears bulky gloves (active site affected) when picking up toothpicks?

 

 

6. Explain what would happen to an enzyme-facilitated reaction if temperature were increased. Be sure to include the effect if temperature were increased to 100°C.

 

 

7. What is the optimal temperature (°C) for enzymes functioning in the human body?

 

 

  BACK

 

TRAINING – HOW TO USE SMART BOAR

TRAINING – HOW TO USE SMART BOARDS
http://www.teacheronlinetraining.com/complimentary/ – Online training(60 minutes)
SMART BOARD FORUMS
Learn and share with other educators.
http://smartboardrevolution.ning.com/ – All SMART Board educators, unite! Let’s share ideas, tips, and lesson files and collaborate to maximize our students’ learning.
http://projects.minot.k12.nd.us/groups/smarttechnologies/ – SMART board Technology site: area to share and learn.
LESSONS AND TEMPLATES
http://www1.center.k12.mo.us/edtech/SB/templates.htm – Templates available for K-12 classes. http://eduscapes.com/sessions/smartboard/ – all grades
http://www1.center.k12.mo.us/edtech/resources/SBsites.htm – Interactive sites to use with your SMART board.
GAMES AND QUIZZES
Class Tools – Use this site to create your own interactive games using your curriculum.
http://tinyurl.com/27sbntd – Classroom games and quizzes, and other teacher resources
http://www.jigsawdoku.com/ – Jig Saw Doku http://tinyurl.com/25km2uo – SMART Boards and the Fifty Nifty States and Capitals
SCIENCE
http://www.getbodysmart.com/index.htm – AN ONLINE TEXTBOOK ABOUT HUMAN ANATOMY AND PHYSIOLOGY
SOCIAL STUDIES
http://tinyurl.com/25km2uo – SMART Boards and the Fifty Nifty States and Capitals