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Transport of water and minerals into the xylem (goes up the plant)
Water and minerals can travel through a plant by three routes
Transmembrane route: out of one cell, across a cell wall, and into another cell
Symplastic route: via the continuum of cytoplasm ( the cytoplasm of neighboring cells is connected by channels called plasmodesmata * best one*
Apoplastic Route: Via the cell wall and extra cellular spaces
Ferns eventually became coal.
Water must be present for flagellated sperm.
Ferns WOULDhave become part of the coal deposites.
Woody plants would NOT have become coal
All early plants had flagellated sperm until angiosperms evolved.
Phylum Lycophyta includes club mosses, spike mosses, and quillworts.
Phylum Pterophyta includes ferns, horsetails, and whisk ferns and their relatives
Angiosperms - The “vessel seed” plants, the flowering plants, and they are the most diverse group of land plants. They have flowers, beetles eat the pollen and spread it around when they poop.
Gymnosperms – The “naked seed” plants including the conifers. They don’t have flowers. The gymnosperms have “Naked” seeds not enclosed by ovaries. An example is pine cones, and there are four phyla:
Cycadophyta (cycads) – even though cycads are eaten by beetles like angiosperms, they are still gymnosperms.
Ginkgophyta (one living species: Ginkgo biloba)
Gnetophyta (three genera: Gnetum, Ephedra, Welwitschia)
Coniferophyta (conifer, such as pine, fir, and redwood)
A flower is a specialized shoot with up to four types of modified leaves:
Sepals which enclose the flower
Petals, which are brightly colored and attract pollinators
Stamens which produce pollen on their terminal anthers
Carpels which produce ovules
Sporophylls – Are modified leaves with sporangia
They all have double fertilization. So one sperm will fertilize the egg cell to form a diploid zygote. The other sperm will form the endosperm which provides nutrient for the zygote.
They have flowers for reproduction and produce fruit.
Ovule – Seeds.
Ovary – The fruit.
Fruit – the ovary.
Style – The shaft that supports the stigma.
Stamen – The shaft that holds up the pollen.
Stigma – Sits on top of the style, and it collects pollen.
Micropyle - is small opening in the surface of an ovule, through which the pollen tube penetrates, often visible as a small pore in the ripe seed.
Vascular Tissue – carries out long-distance transport of materials between the root and shoot systems. The two types of vascular tissue are called xylem (with tracheids) and phloem; they serve as the plumbing for the plant.
Epidermal Tissue – is the plant’s outer protective covering. It is usually a single tissue that is a layer of tightly packed cells. The cuticle is on the surface of the epidermal tissue
Meristem – 746-47
Ground Tissue – Tissue that is neither dermal dermal nor vascular are part of the ground tissue system. It is not just a filler, it includes various cells specialized for functions such as storage, photosynthesis, and support.
Xylem – conducts water and dissolved minerals upward from roots into the shoots.
Phloem – Transports sugars down the plant to where they are needed.
Sieve Tubes – Sieve tubes are mainly to transport sugars and nutrients up and down the plant.
Tracheids – Thick cells, dead, and found in hollow xylem. Have a smaller diameter that can move water higher up plants.
Vessel Elements – Have a thicker diameter so they can’t move water as high up a plant, but they can move more water at the same time. They are thick cells that are dead. A vessel element is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements are typically found in the angiosperms but absent from most gymnosperms such as the conifers. Vessel elements are the building blocks of vessels, which constitute the major part of the water transporting system in the plants where they occur. Vessels form an efficient system for transporting water (including necessary minerals) from the root to the leaves and other parts of the plant
Parenchyma Cells – They are the least specialized cells. They perform most of the metabolic functions, and they can divide and differentiate. (white fleshy part of the apple).
Collenchymas Cells – They are structural cells. They are grouped into strings and they help support the young plant cells. They are thicker and have uneven cell walls. They provide flexible support without hindering growth. Example is the stringy stuff in celery.
Sclerenchyma Cells – they provide the plant with strength. They have rigid structure; they are thick secondary walls that are strengthened by lignin. They are dead when at full maturity.
The waxy casparian strip of the endodermal wall blocks apoplastic transfer of minerals from the cortex to the vascular cylinder and filters material symplastically
The casparian strip ensure that all water and dissolved substances must pass through a cell membrane before entering the xylem in the stele.
Guttation is the appearance of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses. Guttation is not to be confused with dew, which condenses from the atmosphere onto the plant surface.
At night, transpiration usually does not occur because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes, forming drops. Root pressure provides the impetus for this flow, rather than transpirational pull.
So at night the root pressure is high and it forces water out the leaves.
Water potential is the combined pressure and osmotic gradient that determines the potential of water to move. The lower (more negative) the water potential, the more the water has the capacity to move. Water flows from high water potential areas to low water potential areas. (high pressure to low pressure) So the higher structures in the plant needs to have lower water potentials, to draw the water so high.
The leaves of the plant at the top would have the lowest water potential of all.
Transpiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants (similar to sweating), especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants they are more numerous on the undersides of the foliage. The stomata are bordered by guard cells that open and close the pore. Leaf transpiration occurs through stomata, and can be thought of as a necessary "cost" associated with the opening of the stomata to allow the diffusion of carbon dioxide gas from the air for photosynthesis. Transpiration also cools plants, changes cell's osmotic pressure, and enables mass flow of mineral nutrients and water from roots to shoots. Mass flow of liquid water from the roots to the leaves is driven in part by capillary action. In taller plants and trees however, the force of gravity can only be overcome by the decrease in hydrostatic (water) pressure in the upper parts of the plants due to the diffusion of water out of stomata into the atmosphere. Water is absorbed at the roots by osmosis, and any dissolved mineral nutrients travel with it through the xylem.
It occurs through xylem cells
Vessels have a larger diameter so they can move more water, but it can’t move it very high into the plant.
Tracheids have a smaller diameter, so they carry less water, but it means that they can transport water higher up in the plant than vessels can.
They have evolved closed stomata which prevent water from escaping out of the leaves during CO2/O2 exchange.
They have developed smaller leaves, or lost their leaves altogether.
Dormancy and C4 photosynthesis
If phloem transport of sucrose flows from “source to sink” what is a “source” and what is a “sink”?
- Movement from sugar sources to sugar sinks
A sugar sources is an organ that is a net producer of sugar, such as mature leaves
A sugar sink is an organ that is a net consumer or storer of sugar, such as a tuber or bulb, a fruit, a young growing leaf a growing root
A storage organ can be both a sugar sink in summer and sugar source in winter
Be able to account for each event in the mass flow of material in phloem.
- Movement of sugars, amino acids, hormones, etc. through the phloem is as follows:
Leaf produces the sugar
Sugar is transported from cell to cell in the leaf
Solutes are moved (actively transported) into the sieve tubes
Water diffuses into the sieve tubes
Sugar moves to a sink
Extomycorrhyzae are the fungus that live outside the cells
Endomycorrhyzae are the fungus that live inside the cells.
Haustoria is a parasite. It has a haustorium which is a structure that one plant sticks inside the other to suck out nutrients.
Dwarf mistletoe is an example of a parasite.
All of the following belong to the lobe-fin clade, except
What is the driving force for evolution, as it pertains to “new” structures within populations?
Animals with mutations that give rise to effective structures will become more abundant
Why have diverse animals such as sharks, and penguins evolved similar fusiform body shapes?
The laws of physics constrain the shapes that are possible for aquatic animals that swim very fast.
Correlation between body size and surface-to-volume ratio.
As body size increases in animals, there is a decrease in the surface-to-volume ratio
Why do multicellular organisms need their cells to be in a liquid medium?
Cells need an aqueous medium for the exchange of nutrients, gases and wastes
What is homeostasis?
The body’s automatic tendency to maintain a constant internal environment
What is endothermy?
Involves production of heat through metabolism
What is shivering thermogenesis. What animals employ this method of incubation?
A female Burmese python incubating her eggs warms them using shivering thermogenesis
What are examples of torpor?
Hibernation and estivation
How to tell if an animal is an endotherm or ectotherm.
An ectotherm is more likely to survive an extended period of food deprivation than would an equally-sized endotherm because the ectotherm invests little energy in temperature regulation
Know what fat has the highest energy output .
Metabolism of specialized brown fat depots in certain animals is substantially increased during non-shivering thermogenesis
Why are certain nutrients “essential” to animals?
An animal that migrates great distances would obtain the greatest benefit from storing its energy as "fat"
Know the fat-soluble vitamins.
Vitamin A, D, E, K
What are the fat-soluble vitamins (yes again)?
A, D, E K
Know which vitamins are deadly at high amounts.
A, D, E K. Fat-soluble. Essential amino acids, essential fatty acids, vitamins, minerals.
What animals and or insects have a crop?
Earthworms, grasshoppers and birds. Used for temporary storage of food, food storage also for nestlings and production of crop milk
What animals have a long cecum?
Muscular stomach chamber that uses ingested pebbles to pulverize food, some food storage which chemical digestion that was begun in the proventriculus continues
Cellulose to simple sugars
Which class of the phylum Cnidaria includes jellies with rounded medusa?
A unique anastomosing connection between the two aortic arches that aid in high level activity in a systemic circulation, which requires large amounts of oxygen in the blood.
The ray-finned fishes are characterized by
a. A bony endoskeleton, operculum, and usually a swim bladder
Know which animals use positive pressure in their respiratory system.
Frogs have positive pressure breathing
Which choice best describes a reasonable evolutionary mechanism for animal structures becoming better suited to specific functions?
C. Animals with mutations that give rise to effective structures will become more abundant
Similar fusiform body shapes are seen in sharks, penguins and aquatic mammals because
C. The laws of physics constrain the shapes that are possible for aquatic animals that swim very fast.
As body size increases in animals, there is
A. A decrease in the surface-to-volume ratio
Multicelluar organisms must keep their cells awash in an internal pond because
B. Cells need an aqueous medium for the exchange of nutrients, gases and wastes
The body’s automatic tendency to maintain a constant internal environment is termed
A female Burmese python incubation her eggs warms them using
E. Shivering thermogenesis
Hibernation and estivation are both examples of
An ectotherm is more likely to survive an extended period of food deprivation than would an equally-sized endotherm because
C. The ectotherm invests little energy in temperature regulation
Metabolism of specialized brown fat depots in certain animals is substantially increased during
D. Non-shivering thermogenesis
An animal that migrates great distances would obtain the greatest benefit form storing its energy as
In which group of animals would you expect to find a relatively long cecum?
Why are cattle able to survive on a diet consisting almost entirely of plant material?
E. They have cellulose—digesting, symbiotic microorganisms in chambers of their stomachs
In which of the following would you expect to find an enlarged cecum?
a. Rabbits, horses, and herbivorous bears
Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body’s cells are likely to have which of the following?
b. A closed circulatory system
Unique in invertebrates is that circulatory systems in molluscs are open in species of small-sized molluscs and are closed in species of large-sized molluscs
In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body
Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart?
Which of the following is an example of countercurrent exchange?
A. The flow of water across the gills of the fish and that of blood within those gills
Countercurrent exchange in the fish gill helps to maximize which of the following?
Which of the following is a characteristic of both hemoglobin and hemocyanin?
C. Transports oxygen
How does hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals?
C. Hemocyanin has protein couples to copper rather than iron
Marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death?
B. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate
Marine birds utilize their nasal glands to eliminate excess salt from the body. It is these organisms that make life at sea possible for species such as albatrosses. Similar salt glands provide the identical function in sea turtles and marine iguanas.
Unlike most bony fishes, sharks maintain body fluids that are isosmotic to sea water.. They are therefore considered by many to be osmoconformers because of the unusual way they maintain homeostasis. They osmoregulate by
C. Tolerating high urea concentrations that balance internal salt concentrations to sea water osmolarity.
Where and from what compound(s) is urea produced?
A. Liver from NH3 and CO2
Which of the following is true of urea? It is
b. The primary nitrogenous waste product of humans.
What is the main nitrogenous waste excreted by birds?
D. Uric acid
Which of the following nitrogenous wastes requires hardly any water for its excretion
c. Uric Acid
Which of the following is true of ammonia?
b. It is soluble in water
The advantage of excreting wastes as urea rather than as ammonia is that
B. Urea is less toxic than ammonia
Birds secrete uric acid as their nitrogenous waste because uric acid
a. Requires little water for nitrogenous waste disposal, which is conductive to the function of flight in terms of weight
Which group possess excretory structures known as protonephridia
b. Insects (Malpighian tubule-frog too)
Unlike an earthworm’s metanephridia, a mammalian nephron
D. Receives filtrate from blood instead of coelomic fluid
African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation?
B. Small stagnant pools do not provide enough water to dilute the toxic ammonia.
The blastopore is a structure that first becomes evident during
c. Spiral and indeterminate cleave, blastopore becomes mouth
Which of the following characteristics generally applies to protostome development?
e. Determinate cleavage
Protostome characteristics generally include which of the following?
d. Absence of a body cavity
Which group consists of deuterostomes?
c. II: Echinoderms, fish, amphibian, reptiles, birds, mammals
Generally, members of which flatworm classes are nonparasitic.
The members of which class of the phylum Cnidaria occur only as polyps?
While vacationing in a country that lacks adequate meat inspection, a student ate undercooked ground beef. Sometime later the student became easily fatigued, and lost body weight. At about the same time, whitish, flattened, rectangular objects full of small white spheres started appearing in his feces. Administration of niclosamide cured the problem. The student had probably been infected by a
Which molluscan class includes members that undergo embryonic torsion
A radula is present in members of which classes?
The heartworm that can accumulate within the hearts of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong?
The water vascular system of echinoderms
B. Functions in locomotion, feeding and gas exchange
Which of the following is a shared characteristic of chordates?
E. Dorsal, hollow nerve cord
Which of these are characteristics of all chordates during at least a portion of their development?
In which of these extant classes did jaws occur earliest?
There is evidence that ray-finned fishes originally evolved
f. In freshwater environments
The swim bladder of ray-finned fishes
a. Was probably modified from simple lungs of freshwater fishes
The respiratory pigment of almost all vertebrates and a wide variety of invertebrates is the protein hemoglobin, which is coupled with iron rather than copper.
Most dinosaurs and pterosaurs become extinct at the close of the _____ era.
What groups have nucleated erythrocytes?
Mammalian erythrocytes lack nuclei (unlike those of fishes, amphibians, birds, and reptiles which are nucleated)
Countercurrent flow maximizes 80 – 90% oxygenated blood.
Know which animals use negative pressure in their respiratory system.
Reptiles have negative pressure breathing. Mammals also have negative pressure breathing but with a diaphragm, lowering the lung pressure
Lungs of birds channel air through very tiny air vessels called parabronchi, where gas exchange actually takes place.
Three major groups: egg-laying, pouched, and placental
May have lungs, or gills and may use skin a respiratory system
Birds have negative pressure breathing, but it differs from that of mammals and is more efficient because of which of the following reasons?
b. The maximum PO2 is significantly higher in bird lungs.
Eating of the feces
With which of the following statements would a biologist be most inclined to agree?
a. Humans and apes represent divergent lines of evolution from a common ancestor.
During a dive, the heart rate slows, and all major blood vessels are constricted except those critical to survival under water. Metabolic rate slows, and tissues switch to glycolytic metabolism
What probably accounts for the switch to NDA-based genetic systems during the evolution of life on Earth?
a. DNA is chemically more stable and replicates with fewer errors (mutations) than RNA.
What is an endospore?
They live in harsh living conditions
The largest seaweeds belong to which group?
b. Brown Algae
This phylum contains the mushrooms, shelf fungi, and puffballs
The symbiotic associations involving roots and soil fungiare considered
What is true of stamens, sepals, petals, carpels and pine cone scales?
c. They are modified leaves
What tissue makes up most of the wood of a tree?
b. Secondary xylem
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