Bio 2 Exam 1

Convergent evolution

Organisms with no common ancestor develop similar traits or adaptations in response to similar environmental challenges. This phenomenon often occurs in species that occupy similar ecological niches. ex. mammal and fish

Homologous Structures

Anatomical features in different species that share a common ancestry but may serve different functions. ex. fish and fish

Vestigial Structure

An anatomical feature that has lost most or all of its original function through the course of evolution. Examples include the human appendix and pelvic bones in whales.

Molecular Homologies

Similarities in genes among different species indicating shared ancestry. This provides insights into evolutionary relationships.

Homozygotes

Organisms that have two identical alleles for a specific gene, one inherited from each parent.

Heterozygotes

Organisms that have two different alleles for a specific gene, one inherited from each parent.

Genotype

The genetic makeup of an organism, consisting of the specific alleles it possesses for a given gene or set of genes.

Phenotype

The observable physical characteristics

Microevolution

Changes in a population’s gene pool, such as genes from one generation to the next

Hardy-Weinberg Equation

Allele frequencies will be the same from multiple generations if no change

Hardy-Weinberg Equilibrium (no change)

no muatations, no natural selection, no chance events, no migration, no random mating

Mutation

change in genetic material that is heritable

Radiometric Dating

method for dating fossils using radioisotopes that decay at a constant rate.

Hadean Eon (4,550 - 3,800 Mya)

Volcanism and atmospheric changes, cooling, oceans form

Archean Eon (3,800 - 2,500 Mya)

prokaryote dominated

Proterozoic Eon (2,500 - 543 Mya)

Multicellular eukaryotes introduced

Phanerozoic Eon (543 Mya - Present)

3 Major Eras: Paleozoic, Mesozoic, Cenozoic

How many mass extinctions?

5

Main Human Features?

bipedalism, large brains, and tool use

Smallest Known Cells

archea and bacteria

Ether bonds in their membranes (resistant to extreme conditions) and Isoprene chains

archea

Ester bonds like eukaryotes, cross linked by peptides

bacteria

Cyanobacteria

photosynthetic, abundant in water, only bacteria to generate oxygen, chloroplasts originate from this.

Proteobacteria

ancestor of mitochondria, some form symbiotic relationships like Rhizobium which converts gaseous nitrogen to ammonia

How do bacteria evolve and acquire new alleles?

horizontal or lateral gene transfer

How does reproduction in bacteria occur?

binary fission

Mucilage

slimy coat that holds cells together, dna exchange, repels attacks

Biofilm

aggregations of microorganisms that secrete adhesive mucilage

What are the cell walls of bacteria made of?

peptidoglycan

Gram + Bacteria

have thick peptidoglycan layer

Gram - Bacteria

have thin peptidoglycan layer and are enclosed by outer layer of lipopolysaccharides (much harder to kill)

Monophyletic

biological group with single common ancestor

Fungi produce a cell wall with this….

Chitin

Osmotrophy

feeding method where the organism absorbs dissolved organic nutrients through its cell membrane

Mycelium

body of fungi

Hyphae

branched filaments of fungi

Heterotroph

cannot make its own food, feeds on other things

Autotroph

creates its own food

Absorptive Nutrition

utilizes digestive enzymes to break down food (animals and fungi use this)

Dikaryotic State

fungi gives nuclei to new cell, now the cell has two nuclei unlike animals

Embryophytes

all land plants (450 Mya)

Tracheophytes (vascular plants)

produce internal water and nutrient tissues that provide structural support as well

Spermatophytes

seed plants (350 Mya)

Heterospory

production of two types of spores, microspores (pollen) and megaspores (ovules)

Gymnosperms

conifers (pines, etc.), ginkgo (stinky), and cycads (similiar to palm trees but have cones)

Dioecious

has distinct male and female reproductive organs on seperate individuals

Angiosperms

flowers, exclusively use double fertilization whiuch provides food for the embryo to develop

Secondary Metabloisms in Angiosperms

terpenes and terpenoids (main compound), phenolic compounds (colors and flavors, cinnamon, etc.), and alkaloids (affect the nervous system, drugs, etc.)

Coevolution

two or more organisms evolve to be specific to each other (ex. curved flower has bird with curved beak to feed)

Zygote

single cell is formed when a female egg and a male sperm join

Sporophyte

attached to gametophyte, nutritionally dependent, lacks conducting tissues

Bryophyte

liverworts, mosses, and hornworts (waxy cuticle but lack tracheids)

Gametophyte

prominent generation and free living

Tissue Differentiation

stems, leaves, and roots

What kind of plants have branched stems and conducting tissues (phloem and xylem)?

vascular plants

Obligate aerobes

require O2 to survive (many prokaryotes)

Obligate anaerobes

poisoned by O2

Aerotolerant anaerobes

do not use O2 but also not poisoned by it, obtain energy through fermentation or anaerobic respiration

Facultative anaerobes

can switch between O2, fermentation, or use inorganic chemical reactions for energy

Protists

eukaryotes that are not in the plant, animal, or fungal kingdoms (algae, diatoms, etc)

Anther

head that produces pollen (male gametophytes)

filament

thin stalk that supports anther

stigma

sticky top to collect pollen

style

tube that connects stigma to ovary

ovary

contains ovules, after fertilization develops into a fruit