Biology Lab Final

Scientific Method

1. Observe 2. Ask a question 3. Research 4. Hypothesis 5. Experiment 6. Analyze Data and form conclusions 7. Hypothesis is or is not supported 8. Report or revise

Hypothesis

A potential explanation of our observations of the external world

Hypothesis must be

testable

Conclusions should be...

consistent and verifiable

Define chemistry

the study of composition, properties, and reactivity of matter

How many known atoms are shown on the Periodic Table of Elements?

109

Atomic number is what

the number of protons

Atomic Mass

average mass of all the subatomic particles found in a atom

There are several types of chemical bonds that atoms can form depending on their....

Electronegativity

Define electronegativity

tendency of an atom to "pull" electrons toward it

Electronegativity depends on...

an atom's atomic number and the distance at which its valence electrons are from the nucleus

2 basic types of bonds

Covalent and Ionic

2 types of covalent bonds

polar and nonpolar

Define peptide bond

A non polar covalent bond that joins together chains of amino acids, which construct DNA

What are "dipoles" and what is an example.

They are molecules with distinct positive and negative ends. An example of a dipole molecule is water. H2O

In a water molecule are the electrons more drawn to the Oxygen or Hydrogen atoms?

They are more drawn towards the oxygen atom. Giving the oxygen atom and slightly negative charge.

Noble elements are

stable

Define ions

atoms that have gained or lost electrons

Define hydrogen bond

a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

What is the pH scale based on?

the concentration of free hydrogen

What does a one-unit change in the pH scale really mean?

In represents a ten-fold change in hydrogen ion concentration

Low pH has

a greater concentration of hydrogen ions and is therefor acidic

What is pH paper?

filter paper that has been treated with a natural water-soluble dye so it can be used as a pH indicator.

How does ice keep a cup of water cold?

Ice absorbs the heat energy from the liquid water causing the water molecules to move more slowly.

If there is a 4 pH level difference then...

there is 10,000 more hydrogen ions present

Robert Hooke

first to observe "small chambers" in cork and call them cells.

Who developed the cell theory?

Schleiden and Schwann

What are the three parts of the cell theory?

all organisms are made of cells, all existing cells are produced by other living cells, the cell is the unit of life

Define capsule (in the cell)

protective gelatinous outer layer of some prokaryotes

Define centrioles

structures involved in animal cell division

Prokaryotic characteristics

- simpler and smaller
- Bacteria and Archaea
- circular DNA
- no membrane bound organelles

Eukaryotic characteristics

- Plants, animals, fungi, protists
- linear DNA
- has membrane bound organelles

Anton van Leeuwenhoek

improved lens making and views objects in pond water that had never been seen by humans- microorganisms

ocular lenses

On the upper end of the head.

objective lenses

4 magnifying lenses mounted on the revolving nosepiece. Scanning (4x), low power (10x), high power (40x), and oil immersion lens (100x)

stage adjustment knobs

two knobs that are mounted on a vertical bar that hangs from the right hand side of the stage. Upper knob moves stage horizontally from front to back. Lower knob moves stage horizontally from left to right

total magnification formula

ocular lens magnification times objective lens magnification

When using an objective lens with a magnification greater than 10x one should ONLY use the...

fine adjustment knob

Define Parfocal

Property of microscope which allows objectives to be changed without having to refocus

Define working distance

distance between objective lens and the slide on stage

9 steps to using a Microscope

1. get a slide
2. clean slide
3. start with low power objective lens
4. Use coarse adjustment knobs then mechanical stage knobs
5. Use coarse focus knob to move slide as close up as possible
6. increase distance using coarse focus knob
7. Adjust diaphragm

What is used to stain the cheek cells?

methylene blue

citric acid cycle

biomolecules are further broken down into CO2 while electron carrier molecules pick up excess electrons and hydrogen ions that are produced

alcoholic fermentation

Converts food (glucose) into alcohol (C2H5OH), carbon dioxide (CO2), and ATP. WITHOUT oxygen.

Muscle cells carry out a type of fermentation called

lactic acid fermentation

Yeast

Prefer to carry out alcoholic fermentation without oxygen, but if needed it uses aerobic cellular respiration with oxygen.

Cell Cycle

the process all cells in eukaryotic organisms go through from their "birth" to when they make copies of themselves.

Interphase

the stage in the cell cycle leading up to cellular division. During this phase all the parts of the cell duplicate

Mitosis

follows interphase and it is cellular process necessary for growth and repair of cells in multicellular organisms and in certain organisms it is used as a form of asexual reproduction. During mitosis the nucleus and all its components divide.

Cytokinesis

follows mitosis and it refers to the division of all the other components of the cell, called the cytoplasm

Somatic cells

Only carry out mitosis and do NOT undergo meiosis. Use mitosis to create an exact copy of itself to repair or replace destroyed, old or worn out cells.

G0 phase. G zero

This occurs if the cell does not receive a signal to divide. It will remain in a non-diving state, and will carry out its metabolic activities, but it will not re-enter the cell cycle unless it receives signals to do so

G1 phase

First phase of Interphase. During this phase the cell grows, carries out basic functions and produces molecules
needed to build a new cell if necessary. Chromosomes during this phase are loosely coiled and appear as "strands of spaghetti

S Phase

Second phase of Interphase. During this phase enzymes replicate the DNA in chromosomes. At the end of the S phase each chromosomes now consists of two identical strands of DNA attached at a central region.

Duplicated chromosome

When the chromosome consists of two identical strands of DNA attached at a centromere

Sister chromatids

The two identical strands of the duplicated chromosome

G2 phase

During this phase the cell continues to grow but also prepares to divide. The DNA begins to coil more tightly and this signals cell to being mitosis

Prophase

First phase of mitosis. Chromosomes become more coiled, shorter and thicker, and the nuclear envelope dissolves.

Metaphase

Second phase of mitosis. The chromosomes are arranged near the center of the cell once each of the chromosomes is attached to spindle fibers from each centriole at the poles

Anaphase

Third phase of mitosis. The cell grows longer and the sister chromatids separate and begin to migrate towards each pole.

Telophase

Fourth phase of mitosis. In this phase cell division and reorganization of the contents of the 2 daughter cells begins.

Fertilized cells

Are called diploid cells or 2n

Homologous Chromosomes

Pair of chromosomes that are the same size, same appearance and same genes.

germ line cells

During sexual reproduction, specialized cells that are able to reduce the diploid chromosome number by half, to a haploid number to maintain a constant chromosome number from one generation to the next

Autosomes

All other chromosomes within an organism that are not sex chromosomes.

Alleles

Two different gene forms on the pair of chromosomes may be identical or different. The different forms are called alleles.

Gregor Mendel

the "father' of genetics, and although he had no knowledge of DNA or chromosomes he was able to formulate explanations about inheritance that still hold true today. His key ideas are as follows:
1. There are alternate versions of alleles that give us our

Linked genes

The segregation of alleles into gametes can be influenced by linkage, in which genes that are located physically close to each other on the same chromosome are more likely to be inherited together

sex-linked traits

those that are seen more often in one sex than the other.

sex-influenced traits

Certain genes on autosomes will be expressed more often in one sex or the other and this is often due to the presence of a hormone that is produced in greater quantities by one or the other sex

Population

a collection of individuals of the same species living in a particular area

Gene Pool

a collection of all the alleles of the different genes in a population of organisms of the same species

Gene Mutation

a permanent alteration in the DNA sequence that makes up a gene. Gene mutations are considered a random process, which means there is no apparent aim, reason or pattern to them

Natural selection

defined as the gradual process that increases the frequency of certain inherited traits and decreases the frequency of other inherited traits within a population

Taxonomy

the branch of
science that names and classifies living
things

What is the largest and most inclusive level of taxonomy and what is the least inclusive level?

Domain is the largest and species is the smallest

Phylogenic tree

a diagram that shows the evolutionary relationships between groups of living things.

dichotomous key

a tool that allows the user to determine the identity of items or organisms in an area or situation. Keys usually consist of a series of choices that lead the user to the correct name of a given item

Spider key

When creating a dichotomous key, after the sorting is completed you will end up with a branching diagram sometimes referred to as a "spider key

Fungi

a group of single celled or multicellular heterotrophs, which means they must absorb organic food molecules to get the energy they need to survive

Embryophytes

plants with protected multicellular embryo

Protists

Primarily microscopic and unicellular. All are eukaryotes, with their cells having a nucleus and specialized cellular machinery called organelles. Some are autotrophic and some are heterotrophic

Ecosystem

consists of a community of organisms together with their physical environment - the interacting biotic and abiotic components.

Energy transfer in trophic levels

Only 10% of energy is transferred to proceeding trophic levels

Pyramid of Numbers

represents the total number of individuals of different species at each trophic level.

Pyramid of Biomass

determined by collecting all organisms occupying each trophic level separately and measuring their dry weight

Energy Pyramid

Represents the amount of energy at each trophic level and sometimes shows the loss of energy at each transfer to another trophic level. An energy pyramid is always upward, with a large energy base at the bottom.

Bioaccumulation

the build up of a substance (usually a toxin) as it passes through a food chain

Biomagnification

The phenomenon where the concentration of a substance, such as a toxic chemical, is found at increased amounts in the tissues of organisms at successively higher levels in a food chain.

Biosphere

consists of all living things - the biotic parts, as well as the abiotic parts - the air, soil, water and any other non-living matter that surrounds them and is necessary for their survival

Sustainability

the capacity to survive or last into the future

Physical Parameters

abiotic factors that refer to the physical nature of an area and include the temperature of the area, the type of soil and rocks in an area and the shape of land or body of water in an area

Chemical Parameters

Abiotic factors that refer to the chemical nature of an area, particularly in aquatic ecosystems, and include the pH, dissolved oxygen, nitrate and salinity levels along with many other measures

Biological parameters

Biotic factors that refer to the numbers and types of organisms found in an area