biology lab final

Final Review sheet
Elements of Biology

Digestive Enzymes

Digestion: the mechanical and chemical breakdown of food into smaller particles that can be absorbed
by the bloodstream. We focus on the chemical breakdown. The “Do you like seafood” joke is based on the mechanical aspect of digestion.

Amylase: A digestive enzyme that breaks starch into smaller glucose molecules.

Protease: A digestive enzyme that breaks protein into smaller peptide chains.

Starch: A large complex of glucose molecules (simple sugars) bonded together, used as an energy store
or as a structural component in plants.

Gelatin: A mixture of peptides and proteins that congeals at room temperature.

Iodine Test: Tests for the presence of Starch molecules - polymer

Benedict’s Test: Tests for the presence of reducing sugars (glucose) - single molecules

Denaturation: a process where proteins (and DNA, we’re talking about weak interactions like hydrogen
bonds) lose their specific structure, causing them to linearize. You used a denatured enzyme in your
experiment. It was heated to denature it, prior to you coming into lab. The protein can refold when heat
is removed, but since the enzyme is not in a cell we cannot guarantee it will fold correctly again, thus
possibly losing some of its enzymatic activity.

Remember that enzymes have an optimal temperature, and in this experiment the 37ºC water bath
simulated optimal conditions. One the tubes were removed from the water bath, no further enzymatic
activity occurred. The Benedict’s test and Iodine test only showed us what activity had taken place in the
waterbath

Transport

Xylem: flows upward, carrying water up and out through the stomata, a process called transpiration.

Phloem: flows downward carrying sugars and other molecules from leaves.

Root hairs: Increase the surface area for water absorption. They are the sites of osmosis

Stomata: openings that allow water to evaporate out the opening on the underside of the leaf and lets sir into leaf.

Potometer: a device that measures the rate of transpiration.

Artery: Vascular tissue that carries oxygenated blood to the different tissues.

Capillary: tiny porous blood vessels that allow for diffusion of oxygen and nutrients to cells, along with the absorption of the waste product carbon dioxide.

Vein: Blood vessels that carry carbon dioxide-rich blood back to the heart and lungs to release carbon dioxide and pick up more oxygen.

Right Atrium: Receives deoxygenated blood from the body

Left Atrium: Receives oxygenated blood returning from the lungs

Right Ventricle: Sends deoxygenated blood to the lungs

Left Ventricle: Sends oxygenated blood out aorta to the body

Myocardium: the muscle tissue of the heart

Differences between plant & animal systems: The plant system is made up of two separate tissues, xylem and phloem. The two systems move in one direction (phloem goes down; water goes up). The animal system is one type of tissue, the vascular system. It is a closed system, and circulates throughout the body continuously. Different waste products. Plants give off oxygen as a waste product. Animals give off carbon dioxide.

Development

Sexual Dimorphism: Anatomical differences between males and females

Gamete formation: Through Meiosis, one parent cell divided into four daughter cells. Each daughter cell is unique and has half the number of chromosomes necessary for mitotic division.

Fertilization: Occurs when the the plasma membrane of the sperm and egg fuse. When the two nuclei fuse it is called a zygote.

Zygote: A zygote is a single cell with a full complement of parental chromosomes.

Cleavage: The zygote immediately begins dividing by mitosis. In the final stage you have a hollow ball of cells called a blastula.

Blastula: A hollow ball of cells. The final result of cleavage. The cells are ready to begin gastrulation.

Gastrulation: Division of cells into three cell types: endoderm, mesoderm, and ectoderm.
Cell differentiation: Cells within the three tissue types begin to express different genes, giving them
different properties. Some can become nerve cells, muscle cells, or fat-storing adipocytes.
Tissue and Organ formation: Once the three germ layers form, they split into subpopulations of cells.
Different sets of cells become unique in structure and function as they give rise to different tissues and
organs. Cells differentiate and move to form tissues that form organs.
Growth and tissue specialization: During the final stage of development, organs grow in size and take
on specialized properties and assume special functions. This stage continues into adulthood.
Embryonic Stem Cells: obtained from inner cell mass 5-7 days after fertilization in humans.
Metamorphosis: A biological process where an animal hatches and grows as one form, only to abruptly
change later through cell growth and differentiation. The change usually is accompanied by a different
lifestyle.

frogs take significantly longer (3 years) to metamorphosize than moths (23 days)

Population Growth

Population Dynamics: study of the principals that determine the growth and sustainability of populations.

Population Size: Affected by birth rate, death rate, immigration and emigration.

Carrying Capacity: the maximum size of a population that an environment can sustain.

Carrying capacity is affected by: Abiotic factors: non-living factors-water, air, rocks/minerals, fire, climate; Biotic factors: living factors: animals, plants, bacteria; Limiting Factors: light, temperature, food, competition, predators, disease, space & mating

Density-dependent control: The effect of the factor on the population size is dependent on the original size of the population. Biological factors: diseases, parasites, competition, etc

Density-independent control: The effect of the factor does NOT depend on original size
of the population. Abiotic factors: weather (severe snow storm/drought)

Emigration: migration out of a population

Immigration: migration into a population

Human growth curve: The human growth rate mirrored the hypothesized bacterial growth rate. This is
because Man had learned to create new sources of food and energy to support a larger population.

Nematode growth curve: The nematode growth curve is very similar to the human and bacterial growth curve, except we were actually able to witness the depletion of the nematode’s food source and the resulting population crash. Kind of makes a good argument for sustainable resources, huh?

Hare/Lynx curve: The most ideal curve. Instead of having a bunch of starving reindeer, the hare and lynx populations managed each other and kept either population from spiraling out of control.

Wolves population growth curve in Wisconsin resembles exponential growth AKA J-curve

J-curve: Exponential

S-Curve: Logistic

Oscillating Curve

Eco flask experiment

Biogeochemical cycling - The ways in which an element—or compound such as water—moves between
its various living and nonliving forms and locations in the biosphere is called a biogeochemical cycle.
Biogeochemical cycles important to living organisms include the water, carbon, nitrogen, phosphorus,
and sulfur cycles.

Importance of replication of an experiment - Replication lets you see patterns and trends in your
results. This is affirmative for your work, making it stronger and better able to support your claims. This
helps maintain integrity of data. On the other hand, repeating experiments allows you to identify
mistakes, flukes, and falsifications.

After local extinction, species can recolonize an area if they are introduced by humans or if they migrate
from near-by area.