Lab Exam Final Flashcards
test for the presence of Starch
Potassium Iodine Reagent detects polysaccharide by turning blue/black
1 dropperful of unknown solution
3-4 drops of iodine
Turning violet = pos result
test for the presence of Lipid
Put unknown solution on a piece of brown paper
Allow to dry
hold paper up to light
oily film = pos result
test for the presence of Sugars
Benedicts Reagent detects Monosaccharides by turning red/orange and clumping at bottom
1 dropperful of unknown solution
2 droppersful of Benedict’s
Sit on hot plate for 5 minutes
clumping = pos result
test for the presence of Protein
Biuret reagent detects protein by turning violet color
2 droppersful of unknown solution
1 dropperful of biuret
swirl gently
wait 2 minutes
violet color = pos result
Subunits that make up carbohydrates
Monosaccharides
Subunits of Proteins
Amino Acids
how to focus the dissecting microscope
bring focus knob all the way down to the bottom
adjust oculars until there is a single field of view
center specimen
turn focus knob up until image is focused
the eyepiece on a microscope has a magnification of 10X , what is the total magnification with a 10x objective? What is the total magnification with a 45 X objective?
100 / 450
Why is it important to center a specimen on low power before attempting to focus on it at a high power?
By using low power, you have a wider field of view (you see more of the scene) so you know better which sub-part you want to ‘zoom into’.
what purpose does mitosis serve in development and growth?
Mitosis helps organisms grow in size and repair damaged tissue.
Besides the root tips, where else in plants would you expect mitosis take place in an onion plant?
Tip of the stem
Explain how the substances that stimulate taste and smell receptors are similar.
Taste and smell are sensed by chemosensation. The substances are made up of complex mixtures of chemicals that stimulate special nerve cells in the nose, mouth, or throat.
Photoreceptors are primarily responsible for dark adaptation. Explain how dark adaptation works.
Sensitivity to light increases in the dark because photosensitive pigments are reconstructed from vitamin A.
Bivalves have little sensory ability and heavy shells, while cephalopods have well-developed senses and reduced shells. How are these characteristics adaptive for each group?
These characteristics are different adaptations of survival mechanisms. Because bivalves have little sensory ability they have adapted heavy shells to keep them safe from predators. Cephalopods on the other hand have come to rely on their well-developed senses to keep safe. Some have even been known to gather shells and fully wrap themselves for protection.
Using as examples at least two bilaterally symmetrical organisms and two radially symmetrical organisms, discuss the adaptive value of bilateral versus radial symmetry.
Bilateral: Humans/Horse Radially symmetrical: Jellyfish/Sea star
Bilateral symmetry is more adaptive than radial symmetry for a motile animal because the animal can move faster because it can move in one direction.
Bilateral symmetry favors locomotion by generating a streamlined body.
Describe an experiment to test whether pill bugs are attracted to tannic
acid (a chemical found ln rotting wood)
By use of a choice chamber we can have a control condition in one chamber and the other chamber containing tannic acid. We can place 5 pill bugs into the control chamber and 5 into the acidic chamber and observe the choices they make over a period of time. This will allow us to determine whether they are attracted to, repelled by, or have a neutral response to the tannic acid.
Porifera characteristics
(Sponge)
Spongocoel
Osculum
Mesohyl
Monoecious
Cnidaria characteristics
(Jellyfish)
1) radial or biradial symmetry
2) reproduce both sexually and asexually
3) diploblastic
4) cnidocytes (“stinging cells”)
contain specialized organelle called the nematocysts
5) Alternate between two forms
Medusa- free floating (jelly fish)
Polyp – anemone
6) Three layers:
Epidermis – outer layer
Gastrodermis – inner layer
Mesoglea – jelly-like and non-living.
Characteristics of Platyhelminthes
(Flatworm)
Bilaterally symmetrical
Nematoda characteristics
(Round worm)
non segmented
Mouth
Pharynx
Intestine
Ventral nerve
Reproductive organs
Protective cuticle
Arthropoda characteristics
(insects/crustaceans)
Largest phylum
functional segmentation of the body
the presence of jointed appendages
exoskeleton
Mollusca attributes
(clams, barnacles, octupus, snail)
Asymmetrical
Gil – oxygen exchange
Radula – scrapes food particles
Annelida traits
(segmented worm)
Bilaterally symmetrical
Circular and longitudinal muscles
Chaetae- chitinous hairlike extensions from the cuticle
Four common features appear at some point in chordate development:
Notochord
dorsal hollow nerve cord
Pharyngeal slits
post-anal tail
note
(some of these traits are present only during embryonic development)
