par Eleni Melissis Il y a 3 années
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Seed
Seed plants have special structures on them where male and female cells join together through a process called fertilization The parent plant disperses or releases the seed. If the seed lands where the conditions are right, the embryo germinates and grows into a new plant
Seedless
In seedless vascular plants, the plants reproduce using haploid, unicellular spores instead of seeds. The spores are very lightweight (unlike many seeds), which allows for their easy dispersion in the wind and for the plants to spread to new habitats.
Seedless plants multiply by spores that may produced asexually or as a consequence of asexual reproduction.
Sexual Fertilization Methods
Clownfish gender change
The female clown fish is at the top of the hierarchy, so when she dies, a male changes gender to female to take her place.
Tree Pollen Explosion
Pollen from the male cones of cedar trees is released into the air to be captured by the female cones
Earthworm Mating
Hermaphroditic worms couple in order to fertilize the eggs that each individual carries. The sperm is deposited into the slime tube that forms around the worms, and the eggs are then fertilized after the mating has finished
Coral Spawning
example of external fertilization. The sperm and egg cells are released at the same time one night of the year based on temperature and moon cues.
Salmon Spawning
example of external fertilization. The female deposits her eggs in a small depression, and the male releases the sperm over the eggs.
External
Gametes join outside of the body
Requirements: -Large number of gametes and water
Advantages: Parents do not need to be in the same location at the same time
Disadvantages: Less chance of fertilization
Examples: Frogs, corrals, sponges, many fish species
Internal
Gametes join inside of the body
Requirements: specialized organs and mating rituals
Advantages: greater chance of fertilization and lower number of gametes needed
Disadvantages: Parents must be in the same location at the same time
Examples = birds, reptiles, mammals, some fish species
sexual reproduction results in genetic variety and diversity.
individuals are produced from the fusion of two sex cells or gametes: a male or female cell only containing half the information of a body of somatic cell
in most cases - gametes come from 2 parents - male and female: The offspring are therefore not genetically identical to just one of the parents, as the genetic material comes from two different sources
combination of genetic material is what drives the variation in traits that we see in organisms that use sexual reproduction
Even if 2 offspring have the same parents there are differences between the individuals. This is due to the process of Meiosis from which the gametes are produced.
In some cases, both male and female gametes come from the same individual. Individuals that can produce both male and female gametes are called Hermaphrodites
Most plants and some animals (mostly invertebrates), like earthworms and molluscs, such as snails, are hermaphroditic.
DNA- Deoxyribonucleic acid. The genetic material of an organism.
Diploid -The full chromosome number of a somatic or body cell of the organism.
For example, humans have a diploid number of 46 chromosomes. Each gamete, the egg and the sperm, have the haploid number of 23 chromosomes. The resulting zygote will have the diploid number of 46 chromosomes. Remember, the chromosomes contain the genetic material, or DNA, that codes for all the instructions for the structure and function of that organism. Without the full diploid number of chromosomes, that zygote will not have a full set of instructions needed to form a complete organism.
Zygote- A diploid cell resulting in the fusion of two haploid gametes. Will have full diploid # of chromosomes
Fertilization: When to gametes fuse together
Haploid- Having half of the genetic information of a somatic or body cell of the organism. Chromosomes- A structure that contains DNA that carries traits of that organism.
produces daughter cells that differ genetic material- they also contain the Haploid and a number of chromosomes.
There are variations to each method based on whether the organism is unicellular or multicellular, terrestrial or aquatic, etc., but the general mechanism is the same.
Spores
Spore are reproductive cells that contain identical genetic information to the parent. These sporangia have tough outer cases to protect the genetic material inside. Once released, a sporangium will grow into a new organism if the conditions it lands in are favourable. The parent is preserved in this process
The vascular non seed plant including ferns, the fungi including bread moulds, and the fungi including mushrooms
Fragmentation
the body of the parent breaks into 2 or more pieces, with each piece having the ability to generate the missing parts and form a new genetically identical individual. The original parent is lost in the process.
The animal phylum of flatworms and the animal seastar
Vegetative Propagation
A new genetically identical plant is formed from a piece of root, stem, or leaves from the parent plant. The parent plant is usually preserved in the process.
wide range of plants from all Plantae phyla including non-vascular plants like moss, ferns, cedar trees, angiosperms like trillium.
Budding
a new individual develops from some generative anatomical point of the parent organism. In some species buds may be produced from almost any point of the body, but in many cases budding is restricted to specialized areas. The initial protuberance of proliferating cytoplasm or cells, the bud, eventually develops into an organism duplicating the parent.
The new individual may separate to exist independently, or the buds may remain attached, forming aggregates or colonies. Budding is characteristic of a few unicellular organisms (e.g., certain bacteria, yeasts, and protozoans). However, a number of metazoan animals (e.g., certain cnidarian species) regularly reproduce by budding.
Binary Fission
parent cell undergoes cell division to create two new genetically identical individuals. The original parent is lost in the process.
most members of the bacteria kingdom, the protist Amoeba, and the protist Paramecium
Bacteria prime example
Mitosis
Cytokinesis
Cell division occurs after mitosis
The spindle fibres break down and disappear
The nucleolous reappears
A nuclear membrane forms around each new set of chromosomes.
The cytoplasm (and all of its contents) divides between the two halves of the cell.
Cell membrane forms
2 new daughter cells have been formed.
4 phases of Mitosis
Telophase
Begins when the chromatids have reached the two opposite poles within the cell.
At this time, each of the chromatids is called a single, non replicated chromosome.
The chromosomes begin to unwind and become less visible
Anaphase
The centromere splits apart
The chromatids are pulled to opposite poles of the cell by the spindle fibres
Metaphase
Spindle fibres attach to the centromere of the replicated chromosomes.
The chromatids are guided by spindle fibres to the middle of cell, also known as the cells equator.
Each chromatid has its own spindle fibre attachment in order to ensure that each new daughter cell will contain one of each of the chromatids.
Prophase
Chromatin= Made of DNA and proteins, condenses and thickens to form visible duplicated chromosomes.
Each chromosome appears X-shaped
Chromosomes are made up of 2 chromatids that are held together by a centromere.
Nuclear membrane and nucleus disappear.
Centrioles Migrate to opposite poles of cell.
Spindle fibres start to form between the 2 centrioles
3 main functions
Maintenance
Repair
Growth
used to replicate somatic or body cells of the organism.
happens in all 6 kingdoms
This process allows a single organism to pass on its genetic information from one generation to the next
involves a single parent, the genetic material passed on is identical to the parent organism - barring any mutations.
Process results in genetic continuity
Veins
Veins are blood vessels that carry blood low in oxygen from the body back to the heart for reoxygenation.
Arteries
Blood vessels that carry oxygen-rich blood and other components away from the heart to tissues of the body.
From the nasal cavity, air passes through the pharynx (throat) and the larynx (voice box), as it makes its way to the trachea
At the end of the trachea it divides ito the left and right lungs
air enters the lungs through the bronchi which divide into bronchioles.
the air passes through all the branches of the bronchi into the tiniest air sacs, which are called alveoli. The alveoli are the structures where oxygen and carbon dioxide exchange.
oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.
The layers of cells lining the alveoli and the surrounding capillaries are each only one cell thick and are in very close contact with each other
word equation: carbon dioxide + water → glucose + oxygen
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil.
Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose.
The plant then releases the oxygen back into the air, and stores energy within the glucose molecules.
During photosynthesis, chlorophyll absorbs energy from blue- and red-light waves, and reflects green-light waves, making the plant appear green.
Light-dependent reactions vs. light-independent reactions
Light Independent Reaction
known as the Calvin Cycle
takes place in the stroma, the space between the thylakoid membranes and the chloroplast membranes, and does not require light
energy from the ATP and NADPH molecules is used to assemble carbohydrate molecules, like glucose, from carbon dioxide
Light Dependent Reaction
takes place within the thylakoid membrane and requires a steady stream of sunlight
The chlorophyll absorbs energy from the light waves, which is converted into chemical energy in the form of the molecules ATP and NADPH
Respiration occurs throughout the day and night, providing the plant with a supply of energy.
word equation for respiration: glucose + oxygen → carbon dioxide + water
In this process of cellular respiration, plants generate glucose molecules through photosynthesis by capturing energy from sunlight and converting it into glucose.
The gases diffuse into the intercellular spaces of the leaf through pores, which are normally on the underside of the leaf - stomata. From these spaces they will diffuse into the cells that require them.
Stomata are the are the structures through which gas exchange occurs in leaves. Their opening and closing depends on changes in the turgor of the guard cells. When water flows into the guard cells by osmosis, their turgor increases and they expand. Due to the relatively inelastic inner wall, the guard cells bend and draw away from each other, so the pore opens.
If the guard cells loose water the opposite happens and the pore closes. The guard cells lower their water potential to draw in water from the surrounding epidermal cells, by actively accumulating potassium ions. This requires energy in the form of ATP which, is supplied by the chloroplasts in the guard cells.
4 basic types of Tissue
Connective
binds and supports body parts
blood, ligaments, areolar, bone, adipose, cartilage
Areolar
fills the space inside the organs
gel like with elastic fibers and store fat molecules
cartilage
protects the bones preventing them from rubbing against each other
tough, flexible tissue
ligaments
function as a connection between the bones
fibrous and stretchy
bone
secrets calcium - hardens the bone and supports the main organs of the body
blood
transports gasses and other materials to different parts of the body
Muscle
cardiac
involuntary - contract and relax throughout life
shaped like a cylinder
smooth
provide involuntary movement
intestines, blood vessels
spindal shaped - flat and pointed at the ends and broad in the middle
skeletal
motion, voluntary body movement
long fibres with light/dark band
Nervous
cell body, nucleous, dendrites, axons, brain, spinal cord
Open Circulator
a system where blood is pumped into body cavities, where the tissues are surrounded by the blood.
Single Closed
a single loop of vessels in which blood circulates.
fish
Double Closed
two loops of vessels in which blood circulates; the systemic, or body, loop and the pulmonary loop.
humans
Epithelial
covers internal and external surfaces of the body
Columnar
impermeable barrier
catch ingested bacteria
tall - shaped like a column
Cubodial
Absorbtion/mechanical support, forma lining of kidney tubules
Shaped like a cube
Stratified Squamous
found in skin - multilayered
Simple Squamous
lining in the alveoli - thin, flat, single layered
animals that have a backbone
belong to phylum chordata
internal skeletal system
7 classes of vertebrae
Chondrichthyes
organisms with a cartilaginous skeleton
found in the ocean
Osteichthyes
true fish
fused teeth, lobed fins, and a skull
clown fish
Agnatha
jawless animals that look like fish
large head, notochord and sensory system
heterostraci
Amphibia
cold blooded
spend part of their lives in water
some have gills
frogs and salamanders
Reptilia
cold blooded, 4 legged animals. They have a tail and dermal scales. Eggs are fertilized internally
crocodiles, turtles
Aves/Birds
wings, feathers, beak, reproduction involves laying eggs
kiwi, chicken
mammal
epidermal hair, females give birth, suckle young
dog, bear, deer
8 classifications
Mollusca
octopus and squid
Arthropoda
insects
Annelida
earthworms
Platyhelminthes
flatworms
Echinodermata
starfish
Cnidaria
jellyfish
Ctenophora
comb jellies
profera
sponges
animals that lack a backbone
share 4 common traits
reproduce by 2 reproductive cells or gametes - coming together to produce a new organism
no cell walls
multicellular
they do not have a backbone
xylem, phloem, roots, stems, leaves
reproduce without water
ferns
seed producing
seeds let plants reproduce without water
seeds are dispersed through pollination
cones
produce flowers and fruits
seeds are enclosed in fruits
dicots and monocots
can reproduce without water
non vascular
seedless
have a protective cuticle
have stomata for gas exchange
no leaves or roots
instead of roots drawing moisture - each cell gets water through osmosis
no poem - sugars can not be transported around the plant
each cell needs to undergo photosynthesis to create the sugar it needs
A tiny pore found in the epidermis to allow gases to move between the inner leaf and atmosphere.
The vascular tissue in plants that conducts sugars and other metabolic products downwards from the leaves.
the vascular tissue in plants that conducts water and dissolves nutrients upwards from the roots to the leaves.
Surround each stoma to regulate pore size and ultimately the gas exchange.
loosely packed cells allowing gases to circulate around them. They allow for the interchanging gases needed for photosynthesis.
found directly below the epidermis. It is tightly packed and elongated to capture light energy. Also the location of many chloroplasts.
layer of cells on top and bottom of leaf for protection
3 main Tissue Systems
Vascular Tissue System
transport water and minerals, transport food (xylem tissue, phloem tissue)
Phloem
sieve tube members or sieve elements, make up the main structure of phloem. These cells are similar to the vessel elements found in xylem, but they are narrower and have pitted ends resembling small sieves
Unlike xylem, all the cells in the phloem tissue are alive
Each sieve tube cell is connected via a series of pores to a nucleated companion cell, and it is believed that these cells direct the functions of the sieve tube element.
xylem
tracheids
have angled ends and are narrower than vessel elements
tracheids are found in all types of vascular plants and not just angiosperms
The walls of these cells become rigid due to deposits of lignin and cellulose
Once the cell walls are fully formed, the cell will die, and becomes a rigid hollow tube
vessel elements
only found in angiosperms - flowering plants
tubes stacked end to end
Some elements will have porous end plates, while others don’t have ends at all
The vessel elements are pitted on the sides, and this allows the xylem sap to move laterally to other elements
Ground Tissue System
photosynthesis, food storage, regeneration, support, protection (parenchyma, collenchyma tissue, schlrenchyma tissue)
Dermal Tissue System
protection/prevention of water loss (Epidermis, Periderm)
Transpiration and Transportation in Vascular Plants
vascular plants have phloem and xylem to transport water and nutrients
phloem
moves glucose made in the leaves by photosynthesis and amino acids to the rest of the plant
phloem vessels - made of living cells - transport sucrose and amino acids up and down the plant
translocation - glucose, sucrose, amino acids made from photosynthesis - need to be transported around the plant to every single cell
transport in the phloem is up and down the stem
Phloem - the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as photosynthates, in particular the sugar sucrose, to parts of the plant where needed
xylem -
moves water and solutes from the roots to the leaves
made up of cells that form a continuous tube running the entire length of the plant
roots or vascular bundles are located at the centre to prevent plant from being pulled out of the ground
xylem vessels - made of dead cells/ impermeable to water and tough thick walls
transpiration - evaporation of water from aerial parts of the plant (leaves/stem). Water evaporates from leaves and a suction pressure is created which draws up water through the plant (transpiration pull)
xylem movement - 1 way - root to the leaves
transpiration - roots have root hairs - water passes in by osmosis passing into the root citoplasm and then to xylem vessels from the root to the stem to the leaf
Night
sugar produced by chloroplast gets used up
guard cells lose water by osmosis and shrink or become flacid
stomata close to reduce water loss
Daylight
chloroplast produces sugar - lowers the potential of guard cells and take in water by osmosis.
guard cells get swollen and turgid which causes stomata to open so that water can be lost
root
Function is to absorb water and minerals and to transport food and water and reproduction
Below ground - includes all root material
shoot
function is photosynthesis or to transport food/water reproduction and storage
organs found above the ground - stems, leaves, fruit, flower
2 cotyledons in the seed
vascular bundles on the edge
top root
net veined
pedals are in multiples of 4 or 5
1 cotyledon in the seed
vascular bundles in the stem that spread all around
fibrous spreading roots
parallel veins
Pedals in multiples of 3
act as a protective layer for the seeds
products of reproduction in plants
found in fruits where they germinate and develop into new plants
main agents for reproduction
contain pollen which helps with the pollination of the flower
reproductive products of plants
designed for the process of photosynthesis
all necessary food stored in the leaf
transfers food from leaves to other parts of the plant
delivery agents for water stored in the roots
support systems
responsible for saving up food for later use
support system
deliver water and minerals to the plant
responsible for transferring nutrients to the plant
Organisms that are alive make changes to their internal environment
Living organisms grow and develop
Plants, animals, people, and even microorganism that live can adapt to the world around them
A living organism will interact with another living organism
All living organisms have some form of respiration, though the process may differ between them
To classify an organism as living, it must exhibit some form of movement.
All living organisms reproduce
each question or observation has two possible answers. Essentially, using the key is a process of elimination. At the end of the questions, you are left with only one possible answer
8 taxa, Domain, Kingdom, Phylum, Class, Order, Family, Genius and species.
Kingdom
Old system had 5 kingdoms and Monera and Prokaryotae take place of Archaebacteria and Eubacteria
6 Kingdoms
Animalia
cells have no cell walls or chloroplasts
most reproduce sexually
1.2 million species
Can move
Get energy from eating other organisms
Heteroph Kingdom
Mostly multicellular
Plantae
Possess chloroplasts
Feed themselves
Most have cell walls of cellulose
Most are multicellular
Make glucose from sunlight energy
Autotrophs
Fungi
Reproduce sexually and asexually
Can not move
Made of chitin
Mushrooms, mold, yeasts, smuts, puffballs
structure: consist of hyphae - tubes filled with cytoplasm - thread like strands branch out as they mature and form a tangled mass called a mycelium
Basidiomycota
puffballs, mushrooms, bracket fungi - most decomposers
Ascomycota
yeast - beneficial to humans
some cause serious plant disease
zygomycota
case like fungi - bread and fruit moulds, soil fungi, parasites of insects
Most have cell walls (chitin)
Usually Multicellular, can be unicellular
Heterotrophs
Protista
Some have chloroplasts
Eukaryotic
all protists are aquatic
gas exchange happens through direct diffusion between the cell body and environment
Some have a Cell wall, some don't
Most= Unicellular, Can be multicellular
three types of protists
Fungus
decomposers -feed on dead organic material
slime
Plant like
contain chlorophyll
can photosynthesize
algae
Animal like
protozoans - ingest food from surroundings
amoeba
Autotrophs/Heterotrophs
Archaea
Can reproduce asexually
400 described species
example is pyrolobus fumarii
derived from Greek word meaning ancient
single celled prokaryotic organisms - lack a defined nucleus
single celled
have the ability to make their own food and others must find their food
E. coli, staphylococcus, Salmonella
predominantly unicellular
prokaryotic - lack a membrane bound nucleus
Developed in 1990's
Domain
Have DNA, Bacteria, Archaea, and Eukarya
Eukarya= Nucleous, DNA in the Nucleus
organisms consisting of one or more eukaryotic cells
presence of a membrane-bound nucleus containing the cell's genetic information.
multicellular and visible organisms, like people, animals, plants and trees
Non-cellular life is not included in this system.
Archaea= extremophiles, thermophiles
oldest type of bacteria
live in extreme environments
Bacteria = No membrane, No Nucleus
All bacteria is unicellular
DNA found in nucleoid
reproduce asexually
Structure: cell wall, capsule, plasma, membrane, cytoplasm, ribsomes, plasmid, pili, bacterial flagellum, nucleiod
Shape: diverse but some common shapes - spirillium (spiral), Bacillus (rod shaped), coccus (round), Diplo (pair),staphyla (cluster - looks like grapes) Strepto (chain),
they go from largest to smallest.
become more specific as you move from Domain to Species
Ranks or levels based upon shared characteristics - the more levels 2 organisms share the more closely related they are
Phylogenetic Tree
Phylogenetic Tree is another way to show relationships or how species or groups evolved from common ancestors
Evolutionary development or history of a species = phylogenetic
provides unique names for all organisms
Specific Epithet = lower case letter and italics
Genus = Capital letter and italics
