Biodiversity Flashcards
What is chemoautotroph
Carbon from inorganic carbon
A chemoautotroph is an organism that can produce its own food by using chemical energy, rather than sunlight, to synthesize organic compounds
what is chemoheterotroph
carbon from breakdown of organic substances
what does natural selection cause
heritable variability between individuals in a population
what is the effect of random genetic drift
loss of alleles
reduced genetic variation
whats gene flow
genetic exchange between close populations due to migration of fertile individuals
What is endosymbosis
symbiotic relationship where one organism lives inside another one
What is the evidence that supports a close similarity between bacteria and the chloroplast and mitochondria of eukaryotes
Organelles and bacteria similar in size
-Replication by mitochondria and chloroplasts resembles binary fission in bacteria
-The single circular DNA in chloroplast and mitochondria lack histones , as in most prokaryotes
What are the protist supergroups
Excavata
SAR
Archaeplastida
Unikonta
What is a hetertroph
organism that eats other plants
What are the three phyla of the supergroup Excavata
Diplomands parabasalids Euglenozoans
What are the phylas (subgroups) of Euglenozoa
euglenids and kinetoplastids
What are the phyla for the supergroup SAR
diatoms
golden algae
brown algae
dinoflagellates
apicomplexans
cilliates
what are the phyla for the sub group stramenopila
diatoms
brown algae
golden algae
what are the phyla for the sub group of alveolata
dinoglagellates
apicomplexans
cilliates
are diatoms multicellular or unicellualr
unicellular
what are the phyla for the supergroup archeoplastida
red algae
chlorophytes
charophytes
what is the subgroup for unikonta
amboezoans
what are the phyla for the supergroup unikonta ( the phyla for the subgroup amboezoans
slime molds
tubulinids
entamoebas
what two types of lineages do slime molds include
plasmodial slime molds
cellular slime molds
why was the colonisation of land by plants so important
-They altered the composition of air by increasing the oxygen content
-Create habitats for other organisms
-Provide a food course for animals
What traits do land plants and charophytes share
peroxisome enzymes in both land plants and charophytes
what does water provide to plants
nutrient transport from water
support
stable temperature
what is the solution for desiccation on land for plants
-They form a cuticle layer with stomata which prevents water loss
What are the major features found in land plants but not charophytes
-Apical meristems
-Multicellular gametangia
-Alteration of generations found in land plants but not charophytes
What plants do cryptogams refer to
-Lower plants
-Seedless plants
-Spore-bearing plants
-Non-flowering plants
what are the features of byrophytes
small due to lack of vasculature
rely on capillary movement of water
what dictates bryophyte growth habitats
-Not strong enough to support tall structures
-Absence of vascular tissues prevents long distance water transport
what are the characteristcs of gametophytes?
Haploid
independent
bears the gametes
sexual reproduction
what are the charactertics of sporophytes
diploid
depdent on gametophyte (bottom layer)
meoisis
what was the significance of cooksonia
It was the first land plant to show apical dichotomous branching
first plant to have vascular tissues
what does homosporous mean
that the spores arent differentiated into male and female
what are the features of horestails
4 appendages attached to the spore
homosporous
what are the charactertics of club mosses
hetersporous
what are gymnosperms
cone-bearing plants with unenclosed ovules-exposed seeds
what are angiosperms
flowering plants with seeds enclosed in carpels
What advantages does gametophyte miniaturistan offer?
-Moist environment prevents drying out
-Protection from UV
what does heterosproous mean
produces two different types of spores which are usually different in size
what do megasporangia form
megaspores
what are megaspores
female gametophytes
what do microsprangia form
microspores
what are microspores
male gametophytes
what are integuments
sporophyte tissue that envelopes the megasporangium
what are the characteristics of seedless plants
-Flagellated sperm
-sensitive to desiccation
what are the characterstics of seed plants
-non flagellated sperm
-us wind/animals to move
-travel vast distances
what are the charactertics of spores
-can survive if local environment not favourable
-single celled so susceptible(cant repair)
-no nutrient supply
what are the characteristics of seeds
-Can survive for extended periods
-multicellular with protective coat
-nutrient supply
what are the 4 gymnosperm phyla
ginokphyta
cycadophta
gnetophyta
coniferophyta
what are the two distinct stages in the life cycle of a pine tree
-Haploid stage (gametophyte)
-Diploid stage (sporophyte stage)
what are microsproangia
Microsporangia are structures in plants that produce microspores, which develop into pollen grains and male gametophytes
what are angiosperms(what type of plants)
Flowering plants
What is a key adaptation of angiosperms
-Double fertilization
How does double fertilization occur in angiosperms
-Pollen grain germinates after landing on stigma
-Pollen tube grows the ovaries
-Penetrates through the micropyle
-Grows a pollen tube
-Signals which that is receiving tells the pollen tube in which direction to grow towards the nucleus to transport the pollen to the nucleus
What is the result of double fertilisation in angiosperms
-Pollen tubes discharges 2 sperm cells into the female gametophyte
-1 fertilises the egg to form a diploid zygote - divides to form the embryo
-other fuses with the 2 polar nuclei to form a triploid cell - divides to form the endosperm
-Way to coordinate embryogenesis and endosperm formation at the same time
Whare the differences between monocot and dicot angiosperms
-Monocots have :
-vascular tissue scattered
-veins that are usually parallel
-Dicots have :
-vascular tissue usually arranged in a ring
-veins usually netlike
What are the three basal angiosperms
-Amorella trichopoda
-Water lillies
-star anise
Did angiosperms evolve from gymnosperms
no
characteristics of fungi
-cell walls made from chitin
-Heterotroph-absorb nutrients
-No chlorophyll
-Growth through hyphae
-Reproduction through spores
-Can be saprophytic(feeding of dead tissue) or parasitic
structure of fungi
Hyphae of septate fungi are divided into cells
Cells can be dikaryotic
Hyphae of coenocytic fungi lack cross walls
Parasitic fungi can have specialised structures called haustoria
what are hyphae
Hyphae are the filamentous structures that make up fungi, oomycetes, and actinobacteria
Fungi life cycle (page 22)
-can either be asexual(default) or sexual(contingency-so if environment changes they can reproduce via sexual reproduction)
-Asexual;
Spore producing structures-spores-germination-mycelium
-sexual ;
Spores-germinate-give rise to mycelium-plasmogamy(fusion of cytoplasm)-karyogamy (fusion of nuclei) -diploid stage-meiosis-back to haploid
what does saprophytic mean
Saprophytic refers to organisms, especially fungi and bacteria, that obtain their nutrients from dead organic matter
what does parasitic mean
Parasitic refers to an organism or lifestyle in which one organism, the parasite, lives on or inside another organism, the host, and derives its nutrients or benefits at the expense of the host.
What is mycorrhiaze
-Symbiotic relationship between plants and fungi
-Plants benefit from increased surface area and mineral uptake
-Fungus benefits from carbohydrates leaking from plant cells (no penetration )
what are the 5 phyla of fungi
Chytridiomycota
Zygomycota
Glomeromycota
Ascomycota
Basidiomycota
what is the functional definition of an animal
Functional definition - multicellular , heterotrophic eukaryotes with tissues that develop from embryonic layers
what is gastrulation
formation of tissue layers
what are HOX genes
HOX genes are a group of related genes that control the body plan and the developmental patterning of organisms during early embryogenesis
was the ediacaran period where the first fossil evidence was found
yes
what happened during the cambrian explosion
-Emergence of predatory-prey relationships
-Increase in oxygen levels
-Evolution of Hox gene
whats bilateral symmetry
Bilateral symmetry refers to a body plan in which an organism can be divided into two symmetrical halves along a single plane
(a distinct left and right side)
whats radial symmetry
Radial symmetry refers to a body plan where an organism can be divided into multiple identical parts by drawing imaginary lines through a central point (like slicing a pizza)
-So multiple lines of symmetry
how many layers of tissue does gastrulation in animals generate, and what are the layers called
two layers
-Ectoderm and endoderm
(a third layer can emerge later , called a mesoderm)
what are triploblasts
Triploblasts are animals that develop three distinct germ layers during embryonic development. These three germ layers give rise to different tissues and organs in the body. Triploblasts are part of a larger group of animals called bilaterians
how do you classify body cavities in animals , what has a body cavity within mesoderm, mesoderm and endoderm and no body cavity at all
-Body cavity within mesoderm - coelom
-Body cavity between mesoderm and endoderm (roundworms)
-No body cavity(flatworms)
what is the phylum for a sponge
Porifera
characteristics of poirfera-sponges (ie what sponges , hox gene or not?)
-No symmetry
-No true tissue -aggregates of different cell types
-No Hox genes
-Reproduction : hermaphroditism ( no gonads)
-Sessile (cant move in any direction) so defences are chemical ,creating a micro environment
-Rich in microbial symbionts (holobiont concept)
-Compounds such as antifouling and antibacterial defences
-Can help human disease - eg - cribrostatin
what is a diploblast
Diploblast - an animal that has two embryonic tissue layers
what is the process in diploblasts that transforms the single layered blastula into a double layered gastrula
gastrulation
what does sessile mean
they dont move
what is a hydrostatic skeleton
-Enclosed volume of fluid used for support and to counteract muscles
-Well suited for aquatic habitat
-Antagonistic effect of longitudinal and circular muscles
do flatworms have a body cavity
no
is the body cavity between mesoderm and endoderm in roundworms
yes
is the body cavity within the mesoderm in annelids
yes
is planarian reproduction asexual or sexual
asexual
what type of symmetry do bilaterians/triploblastics have
bilateral symmetry
how many tissue layers do bilaterians/triploblasts have
three tissue layers
what are the two main groups of annelids
polychaetes and oligochaetes
what type of segmentation do annelida have
metameric segmentation
what does segmentation allow for
a bigger body
what is peristaltic crawling
It involves a series of wave-like muscular contractions that move along the body, allowing the organism to crawl forward in a controlled and coordinated manner.
what is chaetae
Chaetae (also called setae) are bristle-like structures found on the bodies of certain invertebrates, especially annelids (such as earthworms and polychaete worms). These structures are primarily made of chitin and serve a variety of functions related to movement, anchorage, and sensing the environment.
pseudocoelom is a type of body cavity , what does this mean
a pseudocoelom, a type of body cavity. The term “pseudocoelom” refers to a fluid-filled cavity that is located between the digestive tract and the body wall, but it is not entirely lined with mesoderm (the middle germ layer).
-Have fluid-filled body cavity partially lined with mesoderm
are molluscs protostomes
yes
coelom is a type of body cavity what does this mean
Coelom:body cavity lined with mesoderm
what is archenteron
Archenteron:endoderm lined cavity at gastrulation that develops into digestive tract
what are the three major monophyletic clades of bilateral animals
-Lophotrochozoa(annelids and molluscs)
-Ecdysozoa
-Deuterstomia
features of a lophotrochozoa
-Presence of a trochophore larvae
-Feeding structure called lophophore
features of an ecysozoa
-Presence of a steroid hormone called ecdysteroids
-Cuticular skeleton
what is the common ancestor of bilateria
triploblasts
what are the diagnostic features of molluscs
-Protostomic development (Mollusks are protostomes, meaning during embryonic development, the blastopore (the first opening formed) becomes the mouth)
-Mantle cavity (water filled)
-Unsegmented body
-shell
-Hermaphroditism in terrestrial snail meaning they possess both male and female reproductive organs
-Radula= feeding organ of molluscs
what does hermaphroditism mean
meaning they possess both male and female reproductive organs
what does protostomes mean
Mollusks are protostomes, meaning during embryonic development, the blastopore (the first opening formed) becomes the mouth
what is a radula
-Mollusks, especially gastropods (e.g., snails), have a specialized feeding organ called a radula. It’s a toothed, tongue-like structure used for scraping or cutting food, often algae or plant matter.
what are the major classes of phylum mollusca
-monoplacophora
-polyplacophora
-gastropoda
-bivalvia
-cephalopoda
what are chitons
Chitons are marine animals with oval shapes and shells divided into eight dorsal plates
-Chitoms use their muscular foot to grip the rocky substrate tight over the rock surface
-Chitons are grazers that use their radula to scrape and ingest algae
gastropods undergo torsion , what does this mean
Torsion:Gastropods undergo torsion in which the visceral mass is rotated up to 180 degrees , the anus and mantle cantle are above the head in adults
key characteristics of ecdysozoa
-3 layered cuticle
-Molting(ecdysis)
-
what are the features of the Bivalvia - Gastropoda
-No radula
-External fertilisation
-Includes clams and oysters
-Have shelves divided into two halves
-Clams can pull themselves using the muscular foot as an anchor
-The mantle cavity of a bivalve contains gills that are used for feeding and gas exchange
-Most bivalves are suspension feeders trapping fine particles in mucus that coats the gills
what are arthropods
highly diverse phylum of jointed limbed animals
why are arthropods successful
-Jointed appendages
-Exoskeleton (Ecdysozoa)
-Excretory system (Nephridia)
-Segmentation (Tagmosis)
-Compound eyes
what are the components of the insect exoskeleton
-epicuticle
-exocuticle
-endocuticle
what are the benefits and costs of an exoskeleton
Benefits:Prevents water loss (keeping water in , important for terrestrial species), chitin and protein ( strong but can flex)
Costs:Thicker exoskeleton requires for larger muscles (limit on maximum body size) , must moult in order to grow larger
what is exdysis
-Controlled by the hormone called ecdysone
Includes shedding of (everything): anterior and posterior regions of digestive tract , compound eyes
-Each growth stage is counted as an instar stage
-Hardending = scleritisation
what is tagmosis
Tagmosis is the grouping of segments into specialized body regions, aiding functional efficiency
what do compound eyes allow for
Compound eyes allow for enhanced vision with a wide field of view, and their presence in diverse taxa like arthropods, annelids, and bivalves highlights convergent evolution
what are nephridia in arthropods
Function: Nephridia are specialized organs in many arthropods (as well as some annelids) that help in excreting waste and regulating water balance. They play a role similar to that of kidneys in humans by minimizing water loss and allowing the reabsorption of water
what are the ancestors of arthropods
-triplobites
what are the major groups of arthropods
-chelicerata
-myriapoda
-crustacea
-hexapoda
does the chelicerata have anterioir appendages
yes
what is the tagmosis (body) of chelicerata
-Head and thorax fused = cephalothorax
-Two tagmata:Anterior prosoma and posterior opisthosoma
what are the 4 groups of myriapods
-millipedes
-centipedes
-symphyla
-pauropoda
what is the tagmosis of crustacea
Tagmosis of crustacea: three tagmata : head and thorax (cephalothorax) may be fused and abdomens
what are the 3 groups of crustacea
-xenocrada
-oligostraca
-vericrustacea
go over athropod characteristics
Hexapoda characteristics
-three pairs of legs
-Three tagmata
-Adults have two pairs of wings
-On repair of antenna
-Compound eyes
-Tracheal system for respiration
-Mouth parts contain madaparts
what makes insects so successful
-small size
-Highly organised sensory and neuro-moto systems
-Short generation time - faster evolutionary change
-Coevolutionary relationships
-Winged adults, fly to different locations
-Metamorphosis,adults arent in competition with young ones, not eating same food
how do insects respire , ie respiration through what
-Respiration through trachea
-Limits body size-o2 transport less efficient as body size increases
-Branched airways
-Allows insects to colonise land
-Body movement forces c02 out
Why are insects ecologically important?
-recycle nutrients,break down dead material
-plant pollinators
-Maintain plant community composition through grazing
what do the phloem feeders and the malpighian tubules allow for the hexapods to do , in terms of their diet
-Variable diet:phloem feeders (suck up phloem from plants ) so they have too much water and sugar , to overcome this the malpighian tubules remove water and sugars and water is excreted
-Desert insects-don’t have enough water , so the malpighian tubules are tightly bound to the rectum to extract as much water as possible
what are the 4 stages of metamorphosis
metaboly: develop to adulthood with little change in body form
2-Paurometaboly:gradual change in body form , with external wing buds getting lager at each moult
3-Hemimetaboly:gradual change in body form , with external wing buds getting larger at each moult
4-Holometaboly:drastic change from a wingless larva to winged adult stage via a pupal stage
what is holometabolous
Holometabolous refers to a type of complete metamorphosis in insects, where the life cycle includes distinct stages: egg, larva, pupa, and adult. In this type of metamorphosis, the insect undergoes a radical transformation from one stage to the next, resulting in significant changes in body structure and function
What are the characteristics of true sociality
1-Cooperation by individuals other than parents in caring for the young
2-Overlap of at least 2 generation capable of contributing to colony labour
3-Reproductive division of labour
what are the 5 extant classes of echinoderms
-Sea star
-Brittle star
-Sea urchin
-Sea lilly
-Sea Cucumber
are echinoderms deuterostomes
yes
what do deusterostomes contain (ie what 3 groups)
-chordata
-hemichordata
-echinodermata
what are the characertistics of echinoderms
-Have pentaradial symmetry
-Body plan divided into 5 sections / rays
-Skeletal and most organ systems are arranged 5 folded
-Can move with equal probability in any direction (no preferred direction of movement)
do echinoderms have a water vascular system
yes
describe the features of the water vascular system in echinoderms (page 50)
-The water vascular system are fluid filled canals
The WVS consist of a circular ring canal with radially extended canals
-The WVS ends in tube feet (used for locomotion)
-Tube feet are extended and retracted by hydraulic pressure
-The WVS opens to surrounding environment through the hydropore
do echinoderms have a biphasic lifecycle
yes
what are the 2 subphyla of echinoderms
-pelmatozoa
-eleutherozoa
what is pentaradial symmetry
Definition: Pentaradial symmetry refers to a body plan where the organism is symmetrically arranged around a central axis, typically with five or more equally spaced parts. This means the body can be divided into similar halves in multiple planes, usually five
-commonly found in echinoderms
what is secondary bilateral symmetry
Definition: Secondary bilateral symmetry refers to an organism that initially develops radial symmetry during early development (as in the larval stage) but later undergoes a process where the body is reorganized to exhibit bilateral symmetry (left and right sides that mirror each other).
Example: Echinoderms also exhibit this type of symmetry in their life cycle
what are the key characteristics of echinoderms
-pentaradial symmetry
-calcuim carbonate skeleton
-water vascular system
-biphasic life cycle
-decentralised nervous system
-regenerative properties
what are the 5 classes of echinoderms
-crinoids
-asteroids
-ophiuroids
-echinoids
-holothurians
what are the 4 unique traits that chordates have
-post-anal tail
-notochord
-dorsal nerve cord
-pharyngeal slits
what is a notochord (present in chordates)
-Longitudinal flexible rod , situated between nerve cord and digestive tube
-Composed of large , fluid filled cells encased in fibrous tissue
-Provides support and flexible structure
what are pharyngeal slits
-Slits in pharynx which allows water to exit body without having to go through digestive tract
-Used for filter feeding in primitive chordates
-Modified for gas exchange in lower vertebrates
what are the closest relatives of chordates
echinoderms
what is an amniote egg
The amniote egg is a key evolutionary adaptation that allows vertebrates to reproduce in terrestrial environments, where the risk of desiccation (drying out) and environmental damage is significant. The amniote egg is characterized by extraembryonic membranes that offer protection to the developing embryo
do gnathostomes have jaws
tehy are vertebrates which have jaws
what is the first groupof mammals
First group of mammals:Monotremata
-Have hair and produce milk
-Oviparous(lay eggs)
what are the 3 groups of mammals
-monotremata
-marusupialia
-eutheria
what characteristics allow eutherian mammals to be so successful ( example - tiger)
-Placental mammals
-Viviparous
-Embryo develops in uterus , fed through placenta
Success of eutherian mammals
Endothermy , supported by efficient circulatory system : allows relative independence from environment
Relatively large brain size, allows behavioural adaptation
Differentiation of teeth : allows evolutionary adaptation
what 3 things does a bird need for flight
-aerofoil
-low weight’
-energy (endothermy)
what does endothermy mean
Endothermy refers to the ability of an organism to generate and regulate its own body heat internally, maintaining a relatively constant body temperature regardless of external environmental conditions. This is commonly known as being warm-blooded
what are the phyla for protists
unikonta
sar
archeoplastida
excavata
