Biology 2 Lecture exam 1

What are the properties of life

Order

Response to stimuli

Reproduction

Growth and Development

Homeostasis

Energy Processing

Adaptation

Regulation

Homeostasis and Regulation

Cells need appropriate conditions, organisms have the ability to maintain internal conditions despite external fluctuations

Producers (Anabolic Energy Processing

Energy from the sun to chemical energy (photosynthesis)

Consumers (Catabolic Energy Processing)

Chemical energy in molecules from food (cellular respiration)

3 Main Domains of Life

Bacteria

Eukarya (Humans)

Archaea

Virus

An infectious agent that can only replicate within a host organism

Capsid

Genetic information inside a protein shell

Science

a way of knowing – systematic study of the natural world

Who wrote down the scientific method

Sir Francis Bacon

The Scientific Method in order

Make Observation

Question

Form a hypothesis that tries to explain the observation

Make a prediction based on the hypothesis

Experiment

Analyze Data/Results

Report your results / Peer Review

Hypothesis

proposed explanation of a natural phenomenon that has to be testable

Variable

A characteristic that is measured

Independent Variable

Treatment controlled by the experimenter (X-axis)

Dependent Variable

Observed result (Y-axis)

Experimental group

receive a certain treatment

Control group

identical to an experimental group, but without exposure to the treatment

Scientific theories are

Generally accepted

Broad, comprehensive

Thoroughly, repeatedly tested and confirmed

Withstands rigorous scrutiny
Explanation for a set of observations and diverse phenomena

Phylogenetic trees

Evolutionary relationships between organisms are shown with branching
diagrams, can be drawn in many ways, rotated at any nodes

Sister Taxa

More closely related to each other than to any other taxon on the tree, Did NOT evolve from each other but from common ancestor

Speciation event

A speciation event marks the moment in evolutionary history when a single lineage divides into separate species.

How are phylogenetic trees made

They are based on analyzing characters (heritable traits) and group organisms based on shared, derived (new) characters

How scientists name species

Follows phylogeny(evolutionary relationships)

Who is the father of taxonomy

Carl Linnaeus

Rules for Binomial Nomenclature

• 1st name = Genus. Capitalized
  • 2nd name = species. Lowercase
  • Latin (roots)
  • Underlined or italicized

Genus

a group of species that share a set of traits

Trait/Character

an observable characteristic of an organism or species

Taxon

group of organisms that share a unique set of traits

Synapomorphy

shared, derived character state that originated in the most recent common ancestor of a group of organisms.

How to read a phylogenetic tree

Each node (branch point) represents a common ancestor, each taxon or group is united by synapomorphies

Homologous

Similar because of common ancestry

Analogous

Similar because of common function, evolved independently

Rule of simplicity

Parsimony, tree with least amount of steps.

Clades

each of the species that are at the end of branches, A clade is each group in a box

Monophyletic group

Known common ancestor in a clade

Paraphyletic Group

Missing some knowledge on ancestors

Polyphyletic Group

Don’t have a common ancestor, know the least amount

Shape of prokaryotic and chlorplast chromosomes

circular

Shape of Eukaryotic chromosomes

linear

Prokaryotes

No membrane bound organelles, one circular chromosome

Simplest and smallest organism yet globally outweighs all other organisms combined and the most dominant

Prokaryotes

How do most prokaryotes reproduce

Binary Fission (asexual)

What percentage of the sea do prokaryotes make up

90%

Cyanobacteria (Blue-Green Algae)

Not technically algae, only half are actually blue-green

What type of chlorophyll does Cyanobacteria ave

chlorophyll a, oxygen producing photosynthesis

Nitrogen Fixation

Few organisms can turn N₂ Into usable nitrogen

What does cyanobacteria use to turn n2 into nitrogen

Heterocysts, responsible for 1/3 of nitrogen fixation in some environments

Algal blooms

Caused by fluctuations in temperature that make bacteria more buoyant or caused by fertilizer

Prochlorophytes

Photosynthetic bacteria,

produces 20% of oxygen in our biosphere,

most abundant marine organism

What type of chlorophyll do Prochlorophytes contain

Chlorophyll a and b

Zygotic meiosis

Zygote → Meiosis → Haploid cells from meiosis become multicellular organism (Gamete) → Gametes come together for fertilization → REPEAT

Mitosis

1 diploid into 2 diploids (46 chromosomes

Meiosis

1 diploid into 4 haploids (each have 23 chromosomes)

Who performs Zygotic meiosis

Fungi, some algae

Gametic meiosis

Similar to zygotic meiosis, but instead of haploid cells it forms gametes

Who performs gametic meiosis

Animals, some protists, and algae

Sporic meiosis or alternation of generation

Zygote → Sporophyte → Meiosis→ Forms spores → Spores turn into Gametophytes → Fertilization → Repeat

Who performs sporic meiosis or AOG

Plants, many algae

Fusion process is what?

Fertilization

What do sporic meiosis form

Spores

Euglenoids

Algae like, Unicellular protist

Mixotrophic

Can obtain energy and carbon from consuming and photosynthesis

Stramenopiles

Diatoms

Golden algae

Brown algae

What do all stramenopiles have in common

All have fucoxanthins

Diatoms

Provides 25% of all carbon fixation, most unicellular or colonial

How do diatoms reproduce

Mainly asexual, to increase size it sexually reproduces

Oogamy

Type of sexual reproduction where gametes differ in size, females bigger than male gametes

Heteromorphic AOG

Reduced gametophyte, Large sporophyte (produces spores), Zoospores

Protist we talked about

Red Algae, Golden Algae, Brown Algae(ectocarpus

Euglenoids

Green Algae

Dinoflagellates

Diatoms

Chlamydomonas

Contractile Vacuole

Fritschiella

Thallus

More protists we talked about

Cladophora

Ulva Lactuca

Acetabularia (mermaids wine glass)

Halimeda

Spirogyra

Organization of life

Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ system → Organism → Population → Community → Ecosystem → Biosphere

What level of organization is considered alive

Cell

Population (One Species)

All members of one species living in the same area

Community (Many Species)

All different populations living and interacting in the same area

Ecosystem (Many species + nonliving environment)

Community + nonliving environment