BIOL1113 Final: 1/3

Atoms

smallest unit that has the chemical properties of an element

Molecules and macromolecules

atoms bonded together --> molecule

Cells

simplest unit of life… surrounded by a membrane & contain various molecules/macromolecules. Unicellular organisms have one cell (prokaryotic & eukaryotic… things like bacteria

Tissues

in multicellular organisms

Organs

complex multicellular organisms

Organism

all living things are organisms. Organisms are classified as to belonging to particular species. Species are related groups of organisms that share a distinctive form & set of attributes in nature; closely related genetically.

Population

a group of organisms of the same species that occupy the same environment

Community

a biological community; an assemblage of populations of different species; types of species found are determined by the environment and by interactions of species w/ each other

Ecosystem

physical environments formed by interactions of a community of organisms w/ their physical environments

Biosphere

all of the places on Earth where living organisms exist

Discovery science

collection and analysis of data w/o preconceived hypothesis. EX: Leaves on maple trees fall in fall

Hypothesis

defined question that you can go off and test; testable and falsifiable. Not something you can prove, but if experiments support hypothesis, you can fail to reject the hypothesis or it can be consistent with existing data. EX: "the shorter amount of daylight causes leaves to fall"

Theory

a broad explanation of some aspect of the natural world, backed by experiment/data

Role of researcher

write journal/paper

Role of editor

determines if article is sufficient quality and appropriate content

Role of reviewers

identifies weaknesses and strengths about article; can vote either:

Yes (Major): yes this article makes sense, but needs these major revisions

Yes (minor): yes this article is sound, but needs clarification in these areas

No: article is not sound

Evolution

 heritable changes in a population of organisms from one generation to the next

Natural selection

process which eliminates individuals that are less likely to survive and reproduce in a particular environment

Theory of descent with modification through variation and natural selection

proposed with two arguments: 1. Variation in traits --> heritable traits passed from parent to offspring; genetic 2. Natural selection --> in each generation

Vertical descent w/ mutation

DNA passed down across generations.. Occurs w/in a lineage.. Mutations accumulate and new species eventually evolve. Random mutations throughout the cycle that accumulate through time --> phenotypic change

Horizontal gene transfer

genes transferred between organisms/species.. fast gene transfer; inserting a whole gene into the genome of another species

Cell

simplest functional unit of a living organism

Cell theory

1\. all living organisms are composed of one or more cells.

2\. Cells are the smallest unit of life.

3\. New cells come only from pre-existing cells by cell division (mitosis/meiosis)

Nucleus

houses DNA; genetic material.. makes up genome.. self replicating

RNA

ribonucleic acid is genetic material

Plasma membrane

barrier; attachment

Cytoplasm

made of cytosol (liquid)

Proteins

collectively the proteome; give structure and function to the body

Prokaryotic cells

lack internal compartmentalization and have no membrane-enclosed nucleus; bacteria… divide through binary fission

Eukaryotic cells

have internal compartmentalization and have enclosed nucleus; animal and plant cells… divide through mitosis/meiosis

Plasma membrane

a double layer of phospholipids and embedded proteins; forms an important barrier between the interior of the cell and its external environment; liquids and gases flow in and out

Endoplasmic reticulum

network of membranes that may have ribosomes for protein synthesis (rough ER)

Golgi apparatus

site of modification

Animal cell

Plant cell

lack lysosomes, centrioles, have a cell wall and chloroplasts

Genome

complete completement of genetic material in organism

Two key features in DNA: a) Double helix: two strands of DNA form double helix; follow AT/CG rule b) Base pairing: bases in opposite strands pair thru the AT/GC rule

Central dogma

DNA --> transcription (or DNA replication then translation) --> RNA --> translation --> proteins (triples of base pairs (ATCG's) called codons translate into polypeptides; amino acids)

Homologs

members of a pair of chromosomes; homologous chromosomes (in diploids!) are pairs of chromosomes that are very similar to each other

Ploidy: Haploid, diploid, polyploid

Ploidy: # of chromosome sets in a cell

\
Haploid: one set of chromosomes; gametes have 1 member of each pair of chromosomes.. in humans, total of 23

\
Diploid: two sets of chromosomes.. in humans, 23 pairs of chromosomes; 22 autosomes, 1 pair of sex chromosomes

What are the four necessary criteria for genetic material?

Information, replication, transmission, variation

Nucleotides

Building blocks of DNA and RNA

Chromosomes

DNA associated with an array of different proteins into a complex structure

What are DNA pairing rules?

A-T and C-G

Transcription

DNA to mRNA

Translation

mRNA to amino acids

Karyotype

Reveals number, size and form of chromosomes

Cytogenetics

Field of genetics involving microscopic examination of chromosomes and cell division

What are the stages of the cell cycle?

Interphase (G1, S, G2), mitosis and cytokinesis

What occurs in the G1 phase?

Growth and checkpoint

What occurs in the S phase?

Chromosomes replicate, two copies stay joined (sister chromatids), 46 pairs of sister chromatids=92 chromatids

What occurs in G2 phase?

Synthesize proteins

What is mitosis?

Division of cell nucleus to form two diploid cells, sister chromatids separate

What is cytokinesis?

Follows mitosis, division of the cytoplasm

External factors to divide

Environmental conditions and signalling molecules

Internal factors to divide

Checkpoints and cell cycle control molecules

How can CDKs be active?

They must bind to cyclins

What are the checkpoint proteins?

Cyclins or CDK

What are checkpoint proteins responsible for?

Advancing the cell through the cell cycle

What are cyclins?

Group of proteins that control the progression of a cell through the cell cycle by activating CDK enzymes

What are CDKs?

Family of protein kinases involved in regulating transcription, mRNA processing, differentiation in nerve cells

The loss of checkpoints can lead to:

Cancer and mutations

What is apoptosis?

Programmed cell death

What does the G1 checkpoint do?

Checks if conditions are appropriate

What does the G2 checkpoint do?

Checks for DNA damage and replication errors

What does the metaphase checkpoint do?

Checks if attached to spindle fibres

What is mitosis used for?

Asexual reproduction, growth and repair

What is a sister chromatid?

Two identical copies with associated proteins

Centrosome

site where microtubules grow and centrioles are found

Where do microtubules attach?

Kinetochore

Where do chromatids join?

Centromere

What are the three types of microtubules?

Astral, polar, kinetochore

Role of astral microtubules

Position spindles

Role of polar microtubules

Separates poles

Role of kinetochore microtubules

Attach to kinetochores

What is a centromere?

DNA

What is a kinetochore?

Protein

What are spindle microtubules?

Formed from microtubules formed from tubulin proteins

Sexual reproduction in diploid-dominant organisms

two haploid gametes unite to form zygotes

Sexual reproduction in haploid-dominant organism

they form diploid zygote then immediately go thru meiosis and produce four more haploid cells (unlike us; we go thru meiosis then into mitosis)

What are the advantages of pea plants?

Self fertilization, cross fertilization, many traits, easy to breed

How do you perform cross fertilization?

Remove stamens off of the plant you want to fertilize, place pollen from one plant onto the stigma of another

Monohybrid

Single trait

P Generation

True breeding parents

F1 Generation

Offspring of P generation

F2 Generation

F1 self fertilizes, recessive trait reappears

Dominant

Displayed in hybrids

Recessive

Masked by dominant

Allele

Two variant forms of a gene

Genotype

Genetic composition of an individual

Phenotype

Physical characteristics that are the result of gene expression

Law of Segregation

Two copies of a gene segregate from each other during transmission from parent to offspring

Test Cross

To determine if the unknown individual is heterozygous or homozygous dominant, cross the unknown to a homozygous recessive individual: if some offspring are dwarf, unknown was Tt, if all offspring are tall, unknown was TT

Dihybrid

Two traits

How many genes do we have for a character?

Two

Two genes are linked:

Variants are found together in parents and are always inherited as a unit

Two genes are independent:

Variants are randomly distributed

Ratio for independant assortment

9:3:3:1