Biol 1200 exam 2

What is vicariance?

The separation of a large group of organisms from the population due to a geographic barrier

what is dispersal

refers to the movement of organisms from one geographic area to another, often across a barrier such as an ocean or a mountain range.

sympatric speciation

a process of speciation where new species arise from a single ancestral species without any physical barriers separating the two populations. speciation occurs within the same geographic area, and it involves the evolution of reproductive isolation between the populations.

Polyploidy

This occurs when a cell or organism has more than two paired sets of chromosomes. ----- can arise from errors during cell division or hybridization between different species, leading to offspring with different chromosome numbers from their parents. These offspring are often sterile or have low fertility, which can lead to their isolation from the parent populations and the eventual development of a new species.

Habitat differentiation

This occurs when a single population adapts to different ecological niches or habitats within the same geographic area. As individuals within the population become specialized for different niches, they may no longer interbreed and eventually form reproductively isolated subpopulations that can evolve into distinct species.

Sexual selection

This occurs when certain traits or behaviors become more attractive to potential mates within a population. Over time, this can lead to the evolution of distinct subpopulations with different traits, behaviors, or mating preferences, which can eventually lead to reproductive isolation and the development of new species.

Hybridization

This occurs when individuals from different but related species interbreed and produce hybrid offspring. In some cases, these hybrids may be fertile and able to reproduce with other hybrids, but not with either of the parent populations, leading to the evolution of a new species.

Autopolyploidy

occurs when an individual or a population has multiple sets of chromosomes that are derived from the same species. This can occur due to a failure of chromosomes to separate during meiosis or fertilization. As a result, an individual with double or triple the normal chromosome number is formed. The ---------- individual can then self-fertilize or mate with other --------- individuals to form a new, reproductively isolated population.

Allopolyploidy

occurs when two different species hybridize, resulting in an offspring with a complete set of chromosomes from each parent species. The offspring of this hybridization will be sterile because the chromosomes of the two different species cannot pair correctly during meiosis. However, in rare cases, the hybrid plant can undergo chromosome doubling, resulting in a new species with four sets of chromosomes, two sets from each of the parental species. This newly-formed ---------- can reproduce asexually or mate with other ------------- to form a new population that is reproductively isolated from the parent populations.

What happens when isolated populations come into contact?

the outcome of contact between previously isolated populations can be complex and depend on a variety of genetic and ecological factors. Possible outcomes include hybridization, reinforcement of reproductive isolation mechanisms, fusion, stability, and ecological interactions such as competition and predation.

reinforcement

If the populations are partially reproductively isolated, hybridization can result in the production of hybrid offspring with reduced fitness. As a result, natural selection may favor individuals that avoid hybridization, leading to the --------- of reproductive isolation mechanisms

hybrid zones

geographic regions where two previously isolated populations or species come into contact and interbreed, producing hybrid offspring. --------- can occur when populations are separated by a physical barrier, such as a river or mountain range, that is later removed, or when populations expand into new territories and come into contact with previously isolated populations.

speciation by hybridization

is the process by which two different species interbreed to produce a new species. ------- can occur when two closely related species come into contact, and their reproductive barriers are not fully developed, allowing for the formation of hybrid offspring.

Know our system of biological classification (domain, phylum, class, etc.)

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Domain

is the highest taxonomic rank of all organisms taken together. According to the _______ system, the tree of life consists of either three domains such as Archaea, Bacteria, and Eukarya,\[1\] or two domains consisting of Archaea and Bacteria, with Eukarya included in Archaea.

Kingdom

the second highest taxonomic rank, just below domain. ______ are divided into smaller groups called phyla. Traditionally, some textbooks from the United States and Canada used a system of six ________ (Animalia, Plantae, Fungi, Protista, Archaea/Archaebacteria, and Bacteria/Eubacteria) while textbooks in Great Britain, Bangladesh, India, Greece, Brazil and other countries use five ---------- only (Animalia, Plantae, Fungi, Protista and Monera).

Phylum

a level of classification or taxonomic rank below kingdom and above class. ______means a race or a tribe that’s different from others based on some characteristic features.

class

***_____*** is a taxonomic rank (a taxon) consisting of organisms that share a common attribute; it is further divided into one or more orders. In the biological classification of organisms, a _____ is a major taxonomic rank below the *phylum* (or *division*) and above the *order*. For example, Mammalia belongs to the phylum Chordata. Mammalia consists of various orders, such as Chiroptera (bats), Primates (apes), Carnivora (dogs, cats, jaguar, bears, etc.), Cetacea (whales), Proboscidea (elephants), and many others.

order

is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, super__ __,__ is sometimes added directly above order, with sub__ directly beneath __. An ___ can also be defined as a group of related families. Ex. horses and monkeys are both mammals therefore monkeys have an*_____ called primates.\*

Family

is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus.\[1\] A family may be divided into sub-------, which are intermediate ranks between the ranks of ------ and genus. The official ------ names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the ------ Juglandaceae, but that ------ is commonly referred to as the "walnut -------".

What belongs to a ------—or if a described------ should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a -----, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opinions often enables adjustments and consensus.

Genus

a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses.\[1\] In the hierarchy of biological classification, ----- comes above species and below family. In binomial nomenclature, the ----- name forms the first part of the binomial species name for each species within the genus.

E.g. *Panthera leo* (lion) and *Panthera onca* (jaguar) are two species within the ---- *Panthera*. *Panthera* is a --- within the family Felidae.

species

basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A ----- is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.

humans all belong to one ------ (the scientific name of our --- is Homo sapiens), and we differ from other species, such as gorillas or dogs or dandelions.

What is a binomial species name, how is it written out

consists of a genus name and specific epithet. The scientific names of species are italicized. The genus name is always capitalized and is written first; the specific epithet follows the genus name and is not capitalized. There is no exception to this.

What is a phylogeny?

The evolutionary development or history of a species or of a taxonomic group of organisms.

Why do we construct phylogenetic trees?

In a phylogenetic tree, the species of interest are shown at the tips of the tree's branches. The branches themselves connect up in a way that represents the evolutionary history of the species—that is, how we think they evolved from a common ancestor through a series of divergence (splitting-in-two) events.

What is an outgroup?

a group of organisms not belonging to the group whose evolutionary relationships are being investigated.

Why is phylogenetic reconstruction difficult?

The DNA differences is vast

What are the major components of a phylogentic tree (e.g., root, node, branch, sister group, etc.)

Branches, nodes, polytomy, tips, sister taxa, root, outgroup, Monophyletic

Branches

populations or species through time.

Nodes

splitting or cladogenic events, splitting events - normally bifurcating, splitting into two (most resovled state)

polytomy

more than two descendants emerge from a node

tips

terminal nodes, endpoints (present day or end of the line)

sister taxa

groups that occupy adjacent branches on the tree

Taxa plural, taxon singular

an organism or group of organisms

Root

the bottom or basal most node, ancestor to all taxa on the tree

Monophyletic

ancestor and all of its descendants

How are phylogenetic trees constructed

may be built using morphological (body shape), biochemical, behavioral, or molecular features of species or other groups.

Define cladistics

A method of classifying living organisms based on the construction and analysis of cladograms.

Clade

A group of species that includes an ancestral species and all its descendants.

What is an ancestral character?

a character that originated in an ancestor of the taxon

What is a derived character?

trait that appears in recent parts of a lineage, but not in its older members

What is a synapomorphy, why are they important?

Possession by 2 or more organisms of a characteristics inherited from their common ancestor

What is homology?

similarity resulting from common ancestry

What is homoplasy (analogy)?

Similarity in characteristics in different species that's due to convergent evolution, not common descent

How do you differentiate homoplasy from homology on a phylogenetic tree?

how does maximum parsimony help you to select among possible trees

It states that the tree with the fewest common ancestors is the most likely.

Bacteria:

Prokaryotic organisms have peptidoglycan in their cell walls; decomposers, parasites , & autotrophs

Archaea:

Prokaryotic organisms; absence of peptidoglycan in their cell walls

Eukarya:

Membrane-bound nucleus contain several chromosomes

Are Prokaryotes monophyletic? Why or why not?

are polyphyletic b/c there are 2 main lineages that diverged very early in the history of life, the Archaea & the bacteria

When did prokaryotes first evolve, how were they instrumental in changing the atmosphere?

3.5 billion years ago and they were instrumental in changing the atmosphere by eventually producing oxygen, altering earth's early atmosphere. They were only organisms capable of nitrogen fixation.

Where do you find them prokaryotes? Why are they important?

They play a critical role in the recycling of nutrients by decomposing dead organisms and allowing their nutrients to be re-used. They are also important for many metabolic processes

What is nitrogen fixation in plants?

Nitrogen fixation refers to the conversion of atmospheric nitrogen gas (N 2 ) into a form usable by plants and other organisms.

Cocci:

Round shaped

Bacilli:

Rod Shaped

Spirilla:

Spiral shaped

Gram-postive:

Cell wall w/ peptidoglycan and cells look purple

Gram-negative:

Thin/gelatin cell wall w/ peptidoglycan surrounded by phospholipid bilayer & cells look pink

How do bacteria exchange genetic material and reproduce?

Bacteria Conjugation: Transfer of genetic material between bacterial cells by direct cell to cell

\*Bacterial is equivalent of sexual reproduction/mating b/c it involves exchange of genetic material

Chemolithotrophs:

(rock feeders) oxidize inorganic molecules w/high potential energy, such as ammonia (NH3) or methane (CH4). ATP is produced by cellular respiration & inorganic compounds serve as the electron donor.

Phototrophs:

(light feeders) use light energy to excite electrons. ATP is produced by photophosphorylation. Chemoorganotrophs: oxidize organic molecules w/high potential energy, such as sugars. ATP may be produced by cellular respiration, w/sugars serving as electron donors or via fermentation pathways.

Review the human interests in prokaryots - in terms of human health and ecosystem services provided.

Biologist use them to clean up pollutions; they are decomposers, recycling carbon & nitrogen through ecosystem

Be familiar with the role of bacteria in the nitrogen cycle and eutrophication.

Nitrogen cycle: Helps either as free-living entities or symbiotic relationships w/ animals & plants; (cyanobacteria) bacteria breaks down proteins in plants&animals into NH3 through decay; (nitrification) 2 nitrifying bacteria converts NH3 to nitrite, latter converts nitrite to nitrate; (Denitrification) breaks down nitrates into nitrogen & replenishes the atmosphere

Eutrophication:

Bacteria feeds on dead plants; increased # of bacteria reduce oxygen respiration in the H20 by carrying out aerobic respiration

What is the domain Eukarya?

Made up of all organisms w/ eukaryotic cells; animals, plants, and fungi \= eukaryotes, also contain prokaryotes

What is the endosymbiotic origin of eukaryotes - what is the evidence supporting it?

That fact that mitochondria have their own DNA, RNA, and ribosomes, supports the ----------- theory, as does the existence of the amoeba, a eukaryotic organism that lacks mitochondria and therefore requires a symbiotic relationship with an aerobic bacterium.

Mitochondria are most closely related to what group of bacteria?

Alpha-proeobacteria

To what group are chloroplasts most closely related?

Cyanobacteria

Primary:

Process in which eukaryote engulfs another living prokaryote

Secondary:

Eukaryote cell engulfs another eukaryote cell that has undergone primary endosymbiosis

Do protists form a monophyletic group?

no, they are a paraphyletic group because they represent some, but not all, of the descendants of a single common ancestor

Review the human interests in protists - in terms of human health and ecosystem services provided.

Protist are important to the earth's ecosystems b/c they were the 1st complex life on Earth, provide as a food source to many living things. & help clean large bodies of H20

What innovative reproductive technique is first seen in protists, and why is it important?

Sexual reproduction(based on meiosis): produce off spring that are genetically different from their parents

haploid life cycle

The haploid life cycle of protists is a type of sexual reproduction that involves a single, haploid phase in the life cycle of the organism. In this life cycle, the organism spends most of its time in the haploid phase, with a brief diploid phase during the process of fertilization.

The haploid life cycle of protists typically begins with the production of haploid gametes, which are specialized reproductive cells that fuse during fertilization to form a diploid zygote. The gametes are produced by a process called gametogenesis, which involves meiosis to reduce the chromosome number by half. This haploid phase of the life cycle may include a range of developmental stages, including vegetative growth, cell division, and differentiation into specialized cell types.

During sexual reproduction, haploid gametes fuse to form a diploid zygote, which undergoes mitosis to produce a multicellular diploid organism. This diploid phase is usually brief and is followed by meiosis to produce haploid spores or gametes, which develop into the haploid phase of the next generation.

Diploid life cycle

The diploid life cycle of protists is a type of sexual reproduction that involves a single, diploid phase in the life cycle of the organism. In this life cycle, the organism spends most of its time in the diploid phase, with a brief haploid phase during the process of gamete production.

The diploid life cycle of protists typically begins with the production of diploid gametes, which undergo meiosis to produce haploid spores or gametes. These haploid cells then develop into the haploid phase of the life cycle, which may include vegetative growth, cell division, and differentiation into specialized cell types.

During sexual reproduction, haploid gametes fuse to form a diploid zygote, which undergoes mitosis to produce a multicellular diploid organism. This diploid phase of the life cycle may include a range of developmental stages, including vegetative growth, cell division, and differentiation into specialized cell types.

What is alternation of generations?

one haploid and one diploid generation.

What structure produces spores?

sporophyte

What do spores grow into?

Spores can grow into different structures depending on the organism that produced them. In plants, spores can develop into gametophytes, which produce gametes that fuse to form a new sporophyte. In some algae, spores may develop into new haploid individuals directly, while in others, they may develop into gametophytes that produce gametes.

In fungi, spores can grow into a variety of structures, including hyphae, which are the thread-like structures that make up the body of a fungus, as well as specialized structures such as mushrooms or fruiting bodies. The spores of fungi are typically produced in large numbers and can be dispersed by a variety of means, such as wind or water, to colonize new habitats.

In some protists, such as the slime molds, spores can develop into multicellular structures called plasmodia, which can move and feed like a single organism. In others, such as the water molds, spores can develop into structures called zoospores, which are motile and can swim through water to find new hosts.

What structure produces gametes?

Gametes are typically produced by specialized structures called gametangia. Gametangia are multicellular structures that develop from the haploid cells of the gametophyte generation in plants, algae, and some protists. In animals, gametes are typically produced by specialized organs called gonads, such as the testes in males and the ovaries in females.

In plants, the gametangia are typically located on the gametophyte and produce gametes through the process of mitosis. The male gametangium, called an antheridium, produces sperm cells, while the female gametangium, called an archegonium, produces egg cells. The sperm and egg cells can then fuse to form a zygote, which develops into a new sporophyte generation.

In algae and some protists, gametangia may be similar to those found in plants, while in others, gametes may be produced directly by specialized cells. For example, in some green algae, gametes are produced by specialized haploid cells called gametocytes, while in some protozoans, gametes are produced by specialized structures called micronuclei.

What do gametes grow into?

Gametes are haploid cells, meaning they contain half the number of chromosomes as the parent cell or organism. When gametes fuse during fertilization, they form a diploid zygote, which contains the full complement of chromosomes.

The zygote then develops into a new individual through a process of cell division and differentiation. In plants and algae, the zygote develops into a sporophyte, which produces spores through meiosis that can develop into new gametophytes, completing the life cycle.

In animals, the zygote typically undergoes multiple rounds of cell division to form an embryo, which eventually develops into a mature individual through a complex process of growth and development. The specific details of this process can vary widely depending on the organism and its life cycle.

In summary, gametes do not grow into a new individual on their own, but rather combine with another gamete during fertilization to form a new diploid individual, which then develops into a mature organism through various processes of growth and development.

What are the ecosystem services provided by fungi?

Antibiotics, food & yeast

What are advantages and disadvantages of hyphae and mycelia?

Advantages: Structures make it easier to absorb nutrients b/c mycelium is a line of single cells in which each are in contact w/ the environemnt

Disadvantage:

loose H2O quickly

What are mycorrhizal fungi?

Form symbiotic relationships w plants @ the root level; penetrate the structure of plant roots to form an intimate connection that facilitates a 2-way nutrient exchange

Understand how fungi are able to decompose plant tissue and their role in the carbon cycle.

fungi play a crucial role in the carbon cycle by breaking down organic matter and releasing carbon dioxide back into the atmosphere, as well as by contributing to the accumulation of soil organic matter. Their ability to decompose plant tissue is essential for the functioning of many ecosystems, and their mutualistic relationships with plants are also critical for maintaining the health and productivity of these systems.

basics of fungal reproduction

the process of fungal reproduction involves the fusion of haploid cells of opposite mating types, followed by the fusion of their nuclei to form a diploid zygote. This diploid cell then undergoes meiosis to produce haploid spores, which can germinate and give rise to new fungal individuals.

Mating types

Fungi can have one or more mating types, which are determined by genetic differences at the mating type locus. Fungi with different mating types are able to fuse and produce offspring, while those with the same mating type are unable to mate.

Plasmogamy

When two haploid cells of opposite mating types come into contact, they can undergo --------, which is the fusion of their cytoplasmic contents. This results in the formation of a heterokaryotic cell, which contains multiple haploid nuclei from each parent.

Karyogamy:

n order to produce a diploid zygote, the haploid nuclei in the heterokaryotic cell must fuse through the process of --------. This results in the formation of a diploid nucleus, which then undergoes meiosis to produce haploid spores.

How old are plants?

475 million years old

Why are plants also called 'embryophytes'?

they live primarily in terrestrial habitats, while the related green algae are primarily aquatic.

What are the derived traits of plants, and which were the most important in contributing to plants successfully colonizing terrestrial habitats?

* In aquatic habitats, green algae provide oxygen and food for aquatic organisms; on land, plants produce oxygen, build soil, prevent erosion, moderate climate, and provide food for terrestrial organisms
* Plants were first multicellular organisms that could live with most of their tissues exposed to the air. A series of key adaptations allowed this. Plants now dominate terrestrial environments
* A sequence of important evolutionary changes made it possible for plants to reproduce efficiently on land, even in extremely dry environments

Why are plants important for essential ecosystem services?

They improve the atmosphere, surface water, and soil in ways that benefit other organisms. Plants produce oxygen, build and hold soil and water, are primary producers

What are the synapomorphies for green plants?

Chlorophyll a and chlorophyll b , Beta carotene (accessory pigment), membrane bound sacs called thylakoids, Cell Wall Composition, Starch as storage product • Sperm identical in structure

What are the major groups of land plants? Are they monophyletic?

* Non-vascular plants, seedless vascular plants, gymnosperms, and angiosperms.
* They are monophyletic, a single common ancestor gave rise to all the green algae and land plants

Review the basics of plant phylogeny.

The fossil record of land plants is massive •The origin of the oxygen atmosphere occurred not long before the appearance of animals in the fossil record and may have played a role in their origin and early diversification

What is the most derived and diverse group of land plants? What is the primary key innovation for this group?

* Angiosperms
* They have flowers

What are the major key innovations that allowed green plants to diversify on land?

* Preventing water loss (kept cells from drying out and dying) the cuticle and the stomata
* Providing protection from harmful ultraviolet radiation
* Moving water from tissues with direct access to water to tissues without direct access

What was required for plants to successfully transition from an aquatic to a terrestrial habitat?

Cuticle is a watertight sealant that covers the aboveground parts of the plant and gives them the ability to survive in dry environments

Stoma (plural: stomata): Consists of an opening called a pore surrounded by specialized guard cells

* Gas exchange is accomplished through the pore
* Stomata are present in all land plants except liverworts, which have pores but lack guard cells

What adaptation allowed seeded plants able to reproduce in the absence of water?

* seed was a sperm and egg
* Sperm form in antheridia
* Eggs form in archegonia
* Haploid to diploid through meiosis, mitosis, then fertilization

Nonvascular plants and most seedless plants...

* Bisexual gametes produces a sperm and an egg

Seed plants (heterosporous)

* Male gametophyte → sperm
* Female → eggs