LAB MIDTERM

Independent variable

The variable that is altered by scientist

Dependent variable

The variable observed in response to changes made to the independent variable

Replication

Replicating an experiment increases accuracy of results

Control variable

the group compared to the independent group

The scientific method

Ask, research, hypothesis, test hypothesis, analyze data, report results

Cell

- The smallest structural and functional unit of an organism

- ALL living organisms composed of cells

- Typically microscopic and consisting of several key structures enclosed in a membrane.

The Cell Theory

- All organisms are made of cells

- All cells arise from pre-existing cells

- Populations of single-celled organisms all have a common ancestor cell

- All cells in multicellular organism arose from a single cell All living organisms are

Implications of Cell Theory

- All life is cellular

- All cells in a population of sing-celled organisms are related by common
ancestry

- All cells in a multicellular organisms are descended from a single cell

- Hereditary Info. (DNA) is passed on from cell to cell

The 4 components present in all
Cells are:

- Cell membrane
- Nucleic Acids
- Ribosomes
- Enzymes

Cell membrane

selectively permeable, keeps environment out!

Nucleic acids

information carrying molecules in the cell (DNA/RNA)

Enzymes

protein catalysts used to increase the rate of biological reactions

Ribosome

makes proteins needed for cellular function

Three Domains of Life

Bacteria, Archaea, Eukarya

7 levels of taxonomic classification

Kingdom, phylum, class, order, family, genus, and species

Autotrophic

of or relating to organisms that can make complex organic nutritive compounds from simple inorganic sources by photosynthesis

Mixotrophic

an organism that can use a mix of different sources of energy and carbon, instead of having a single trophic mode (both autotroph and heterotroph)

Heterotrophic

requiring organic compounds of carbon and nitrogen for nourishment

Unicellular

having or consisting of a single cell

multicellular

consisting of many multicellular cells

colonial

an organism is composed of attached unicellular cells, but the cells are mostly similar in structure and function, can live on their own,

All plant cells have

cell walls, one vacuole, and chloroplast

Animal cells have

no cell walls, many vacuoles

Bacteria is

the most diverse domain of life

endothermic

an organism capable of internal generation of heat

ectohermic

an organism that regulates its body temp. by exchanging heat with environment

homeothermic

maintaining a constant body temp.

heterothermic

having body temp. that varies with environment

respiration rate

breathing rate of an organism

metabolic rate

rate at which an animal burns calories to produce energy

Specialized cell types

- Plants -> have guard cells

- Animals -> have muscle and nerve cells, etc.

- Volvox (algae) have different cells that have different functions in the colony as well!

cellular respiration

(done by both plants and animals) how an organism can turn food into energy cells can use (aka ATP)

photosynthesis

synthesis of compounds with the aid of solar energy

Body temp. is regulated by...

Reactions occur faster at higher
temperatures, but enzymes have an
optimal temperature at which they work the best.

At temperatures too low or two high, enzymes will lose their ability to bind to substrate and eventually denature.

Alu-PV92

- Located on chromosome 16
- ~300 bp
- Transposon

Transposon

a chromosomal segment of DNA that can undergo transposition within a genome, can reverse/create a mutation

Exon

sequence of a gene's DNA that transcribes into protein structures (affects phenotype)

Intron

sequence of a eukaryotic gene's DNA that is NOT translated into a protein

Regulatory Sequences

segment of nucleic acid molecule that's able to increase/decrease expression of certain genes

DNA isolation

extraction of DNA from cortex and purify nucleic acid to remove any inhibitors

Polymerase Chain Reaction (PCR)

a lab method used to make many copies of a DNA piece from a tiny sample

Gel electrophoresis

a lab method used to separate mixtures of DNA and RNA or proteins according to size

Alu insertions shared by different individuals are identical by descent...

so you can find a common ancestor

PCR steps

Denaturation (heat)- heat splits open DNA double helix

Annealing (cold)- primers bind to ends of target sequence of DNA. Primers tell DNA polymerase where to start copying DNA

Extension/Elongation- new nucleotides are added by a kind of DNA polymerase called Taq, making copies of DNA segment

Animal cell

Plant cell

Matrix