Biology 11 Final Objectives due 12/09/14 Flashcards
What were the adaptations to land that plants had?
One of plants adaptations is structural, Light and carbon dioxide are mainly available in the air, while water and mineral nutrients are found in the soil. Plants are able to take advantage of these two environments by having both aerial leaf-bearing organs called shoots and subterranean organs called roots. Exchange of carbon dioxide between the atmosphere and the photosynthetic interior of a leaf occurs via stomata, the microscopic pores on a leaf’s surface. A waxy layer called the cuticle coats the leaves and other parts of the pant helping the plant body retain water. An important terrestrial adaptation of plants is lignin, a chemical that hardens cell walls. The terrestrial equipment of most plants includes two vascular tissues that are important for transport. The Xylem transports water and minerals from roots to leaves and the Phloem distributes sugars from the leaves to the roots and other parts of the plant.
Another adaptation is reproduction, plants must keep their offspring from drying out in the air. Plants reproduce their gametes in a protective structure called gametangium, it has a jacket of protective cells surrounding a moist chamber where gametes can develop without dehydrating. For most plants, sperm reach the eggs by travelling inside pollen grains, which are carried by wind or animals. The egg remains within the tissues of the mother plant and is fertilized there. The zygote develops into an embryo while still contained within the female parent and keeps the embryo from dehydrating.
What are the unique characteristics of bryophyta?
Bryophyta are unique because they do not have vascular tissue to carry water from soil to aerial parts of the plant, also they need water in order to reproduce for the flagellated sperm to reach the eggs. It has separate female and male structures on the same plant. Gametophyte is the dominant generation with the sporophyte totally dependent on it for nutrition. The cells of a gametophyte are haploid—they have one set of chromosomes. The sporophyte is made up of two diploid cells with two chromosome sets. Gametophytes produce gametes and sporophytes produce spores. The gametophyte and sporophyte alternate generations that take turns producing eachother.
What is unique about vascular plants?
The plant vascular system is made up of two networks of tubes, known as the xylem and phloem, which are the water and food conducting systems. These are not present in nonvascular plants, which is the major difference between the two. The xylem transports water up from the roots and circulates it to all the other sections of the plant’s body. The phloem transports food, nutrients, and photosynthetic material throughout the plant to keep it healthy and growing. The xylem is made up of dead hollow cells known as tracheids. The phloem, however, contains living cells, which are known as sieve-tube members. They have pores to allow the passage of molecules, but lack nuclei and other organs. Their companion cells, or the cells located next to them, function to keep them alive and healthy.
Vascular plants have lignin that helps support larger structures. There are two types of vascular plants, seedless and seed plants. Vascular seedless plants still need water to fertilize—the sperm still needs to swim to the egg. Plants with seeds have gametophytes that are dependent on sporophyte generation. The embryo is protected by the seed and the sperm is encased in pollen. The seeds are carried by wind or animals.
What are the unique characteristics of the seedless plants? What evolutionary advantages does it have over moss and hornworts?
Seedless vascular plants are unique because they have no xylem or trachea and in the phloem companion cells are absent. Vascular seedless plants still need water to fertilize—the sperm still needs to swim to the egg. The two types are; Lycophytes—club mosses and Pterophytes—ferns. The fern has roots, rigid stems, fronds and reproduces with spores instead of seeds. The evolutionary advantage that it has over moss and hornworts is that unlike regular seed-bearing and flowering plants, seedless plants do not go through the regular reproduction cycle of flowering and fertilization. The advantage of reproduction in seedless plants is that they are not dependant on external factors such as pollination by insects.
What is the evolutionary advantage of seeds and pollen?
Pollen and seeds allow genetic dispersal away from water. As plants adapted for terrestrial habitats the gametetophyte generation became smaller and self-contained. This eventually became pollen able to travel by wind or be carried by a pollinator. This allows plants to use sexual recombination over long distances without water to carry the pollen. Seeds have a coat for protection and endosperm (stored food) to support the plant embryo until conditions are right for germination.
What is the gymnosperm and angiosperm life cycles?
Be able to name the parts of the flower.
Be able to describe the life cycles and the alternation of generations for each of the examples given in the powerpoint presentation.
Answer
What are the characteristics that define animals?
Animals are 1. multicellular, 2. heterotrophic (An organism that cannot synthesize its own food and is dependent on complex organic substances for nutrition) eukaryotes that obtain nutrients by ingestion. 3. Lack a cell wall 4. Motile during some point of their life 5. Able to respond rapidly to external stimuli 6. Able to reproduce sexually
What is the animal life cycle?
- Meiosis 2. Fertilization 3.Mitosis 4.Blastula 5.Early Gastrula 6.Later Gastrula 7. Larva
Define zygote
Union of egg and sperm
Define embryo
A developing stage of a multicellular organism.
In humans, the stage in the development of offspring from the first division of the zygote until body structures begin to appear, about 9th week of pregnancy.
Define blastula
A hollow ball of cells in many species-which is an embryonic stage that marks the end of cleavage during animal development.
Define gastrula
Invagination of the hollow ball to form the three germ layers (ectoderm, mesoderm, and endoderm)
Define ectoderm
Outer layer of cells that will eventually develop into the outer layer of cells in the animal (ie. skin or epidermis) and nervous system
Define Endoderm
Inner layeer of cells becomes the innermost lining of the digestive system (and organs such as the liver, pancreas, and thyroid - in humans)
Define Mesoderm
Forms the muscles and other internal organs (such as the heart and kidneys)
Define Larva
Immature individual that looks different from the adult version of the animal.
Define metamorphosis
Change in body form to become the adult (such as the transformation of a larva into an adult)
Define symmetry
Radial Symmetry: parts radiate from the center, so any slice through the central axis divides into mirror images. Bilateral Symmetry: only one slice can divide left and right sides into mirror-images halves.
Define coelom
A body cavity completely lined by tissue derived from mesoderm.
Define pseudocoelom
A body cavity that is not completely lined by tissue derived from mesoderm.
Be able to describe how animal complexity incresased with evolution.
Answer
Define protostomes
invertebrate animal: an invertebrate animal, e.g. a mollusk or arthropod, in which the mouth forms directly from the blastopore
Define deutrostomes
any member of the phyla (Chordata, Hemichordata, Echinodermata, Chaetognatha) in which the anus appears first, developing at or near the blastopore, cleavage is radial and indeterminate, and the mesoderm and coelom form from outgrowths of the primitive gut.
Define polyp
Polyps are one of two forms of the cnidarians. Polyps may be sexual or asexual. The other body form is the medusa. When medusae mate, the result may be polyps, when polyps replicate, the result may be medusae.
Define medusa
In biology, a medusa (plural: medusae) is a form of cnidarian in which the body is shaped like an umbrella. The other main body-form is the polyp.
What are the characteristics of phylum porifera?
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What advances do we see with cnidara?
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What advances are seen with the platyhlminthes (flat worms)?
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What advances are seen with Nematode (round worms)?
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What advances are seen with Nematode (round worms)?
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What are the characteristics of Mollusca?
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Etymology:- From the Latin Molluscus meaning soft of body.
Characteristics of Mollusca:-
1)Bilaterally symmetrical.
2)Body has more than two cell layers, tissues and organs.
3)Body without cavity.
4)Body possesses a through gut with mouth and anus.
5)Body monomeric and highly variable in form, may possess a dorsal or lateral shells of protein and calcareous spicules.
6)Has a nervous system with a circum-oesophagal ring , ganglia and paired nerve chords.
7)Has an open circulatory system with a heart and an aorta.
8)Has gaseous exchange organs called ctenidial gills.
9)Has a pair of kidneys.
10)Reproduction normally sexual and gonochoristic.
11)Feed a wide range of material.
12)Live in most environments.
Describe the three classes of Mollusca.
Answer
class gastropoda (snails) class cephalopoda ( octopi and squid) class bivalvia ( mussels and clams)
What are the characterisitics of Annelida?
Answer
Symmetry and Size. Annelids are all bilaterally symmetrical animals. …
Coelom. Nearly all annelids have a fluid-filled cavity between the outer body wall and the gut, and this is referred to as a coelom (Figure 1). …
Body wall. …
Parapodia. …
Nervous system. …
Sense organs. …
Circulation and respiratory structures. …
Segmental organs.
What are the characteristics of Arthropoda and what are the three classes? What are the the characteristics of each of the three classes?
Answer
The three main classes of arthropods are: insects (cockroachs, ants, flies, bees, beetles, butterflies), crustaceans (crabs, lobsters, shrimps, barnacles) and arachnids (scorpions, spiders, mites). Other classes are onychophorans (velvet worms), diplopods (millipedes) and chilopods (centipedes).
Divided into 3 classes; Arachnida, Merostomata & Pycnogonida
Body divided into 2 regions
Abdomen
Cephalothorax (fused head & thorax)
Lack jaws
Have 6 appendages & no antennae
First appendages form chilicerae (frequently fangs)
What are the characteristics of Echinodermata?
Answer
Characteristics of Echinoderms. Echinoderms are characterized by radial symmetry, several arms (5 or more, mostly grouped 2 left - 1 middle - 2 right) radiating from a central body (= pentamerous). The body actually consists of five equal segments, each containing a duplicate set of various internal organs.
What is a watervascular system?
The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation, and respiration.[
What are the characteristics of chordata? What are the two subphylum?
Answer
These characteristics are only present during embryonic development in some chordates.
The notochord provides skeletal support, gives the phylum its name, and develops into the vertebral column in vertebrates.
The dorsal hollow nerve cord develops into the central nervous system: the brain and spine.
Subphylum Chelicerata
and
Subphylum Mandibulata
What are the characteristics of lampreys?
Answer
Adults physically resemble eels, in that they have no scales, and can range from 13 to 100 cm (5.0 to 40 inches) long. Lacking paired fins, adult lampreys have large eyes, one nostril on the top of the head, and seven gill pores on each side of the head. The unique morphological characteristics of lampreys, such as their cartilaginous skeleton, suggest they are the sister taxon (see cladistics) of all living jawed vertebrates (gnathostomes), and are usually considered the most basal group of the Vertebrata. Instead of true vertebrae, they have a series of cartilaginous structures called arcualia arranged above the notochord. Parasitic lampreys feed on prey as adults by attaching their mouthparts to the target animal’s body, then using their teeth to cut through surface tissues until they reach blood and body fluid. Although attacks on humans do occur, they will generally not attack humans unless starved. Non-parasitic lampreys, which are usually freshwater species, do not feed as adults; they live off reserves acquired as ammocoetes (larvae), which they obtain through filter feeding.
What advances do we see with Chondrichthyes (sharks and rays)?
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What are the characteristics of Osteichthyes (bony fish)?
Answer
Bony fish are characterized by a relatively stable pattern of cranial bones, rooted, medial insertion of mandibularmuscle in the lower jaw. The head and pectoral girdles are covered with large dermal bones. The eyeball is supported by a sclerotic ring of four small bones, but this characteristic has been lost or modified in many modern species. The labyrinth in the inner ear contains large otoliths. The braincase, or neurocranium, is frequently divided into anterior and posterior sections divided by a fissure.
Bony fish typically have swim bladders, which helps the body create a neutral balance between sinking and floating. However, these are absent in many species, and have developed into primitive lungs in the lungfishes. They do not have fin spines, but instead support the fin with lepidotrichia (bone fin rays). They also have an operculum, which helps them breathe without having to swim.
Bony fish have no placoid scales. Mucus glands coat the body. Most have smooth and overlapping scales of that are ganoid, cycloid or ctenoid.
What are the major adaptations to land seen in amphibians?
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What are the major adaptations to land seen in reptilia?
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What are the evolutionary advances seen in aves?
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What are the characteristics of Mammalia?
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1) Warm blooded.
2) Possess hair which is made of keratin. The evolution of mammalian keratin is believed to be independent of reptilian keratin. Hair provides insulation .
3) Endothermic. The majority of the heat energy is used to maintain their high body temperature.
4) Four chambered heart.
5) Mammary glands are used to produce milk to nourish their young. Female glands are the only functional glands.
6) Thediaphragm is a muscle that separates the thoracic cavity from the abdominal cavity.
7) Seven cervical vertebrae (neck bones) are present in most mammals.
8) Most are viviparous though some are oviparous. An extended gestation period uterine development is common in most placental mammals.
9) Teeth are imbedded in the jaw bone and come in a variety of forms.
10) Well developed brain.
11) Mammals developed from the therapsid ancestors during the Triassic period.
12) Mammals are heterodontic, meaning that their teeth are different shapes, except those with no teeth at all.
13) Reptiles and fish have teeth that are all basically the same, though they can vary in size throughout the mouth. See image above.
14) The Buccal Cavity (the mouth) has a false palate as a roof, meaning that the nostrils do not lead directly into his mouth.
15) The body is maintained at a constant temperature they generate heat within their bodies metabolically and also have special cooling mechanisms.
16) Highly developed neopallium.
17) Tectum reduced to corpora quadrigemina: functions mainly as a relay center for auditory information and to control visual reflexes.
18) Corpus callosum in eutherians provides additional communication
19) Smell acute except whales and higher apes.
20) Eye typical of amniotes.
21) Tapetum lucidum well developed in nocturnal mammals.
22) Touch- most have vibrissae that are controlled by facial muscles.
23) Lateral movement of jaw during mastication.
24) Viviparous except monotremes which are egg lying.
25) Parental care well developed.
Define: Herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material for the main component of its diet.
Define Carnivore
is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue.
Define Omnivore
is an animal that can derive its energy and nutrients from a diet consisting of a variety of food sources that may include plants, animals, algae, fungi and bacteria
What is a suspension feeder?
are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure.
What is a substrate feeder?
Organism that lives on their food source. Ex. lice (live on the skin and feed off skin , termites live in wood and feed off wood), caterpillars, maggots and fruit
What is a fluid feeder?
Fluid feeders are organisms that feed on the fluid of other organisms. It can refer to:
Hematophagy, feeding on blood
Nectarivore, feeding on nectar
Plant sap feeders
Leeches
What is a bulk feeder?
Ingest large pieces of food. Ex: Boa constrictors eat mouse whole.
Be able to follow food through the digestive tract.
Answer
Be able to describe the evolutionary advances in the digestive tract from no digestive tract to one opening to two and to compartmentalization.
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Be able to describe the digestion that takes place in the mouth.
Answer
The digestion that occurs in the mouth is both mechanical and chemical. Your teeth and tongue are involved in mechanical digestion, helping you to grind and mix the food to make it easier to swallow. Saliva secreted from salivary glands provides the chemical digestion, which helps to break down foods in the mouth.
Describe what happens during swallowing the movement of the food down the digestive tract.
Swallowing, which is accomplished by muscle movements in the tongue and mouth, moves the food into the throat, or pharynx. The pharynx, a passageway for food and air, is about 5 inches (12.7 centimeters) long. A flexible flap of tissue called the epiglottis reflexively closes over the windpipe when we swallow to prevent choking.
From the throat, food travels down a muscular tube in the chest called the esophagus. Waves of muscle contractions called peristalsis force food down through the esophagus to the stomach. A person normally isn’t aware of the movements of the esophagus, stomach, and intestine that take place as food passes through the digestive tract.
At the end of the esophagus, a muscular ring or valve called a sphincter allows food to enter the stomach and then squeezes shut to keep food or fluid from flowing back up into the esophagus. The stomach muscles churn and mix the food with acids and enzymes, breaking it into much smaller, digestible pieces. An acidic environment is needed for the digestion that takes place in the stomach. Glands in the stomach lining produce about 3 quarts (2.8 liters) of these digestive juices each day.
Describe what digestion is taking place in the stomach and the role the stomach plays in digestion.
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Describe the digestion that takes place in the intestines and the organs that are involved and the role those organs play.
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Where does the majority of the absorption take place in the digestive system?
Most of the absorption of food takes place in the ileum of the small intestine. The villi lining the walls absorb the nutrients from food.
Where does the majority of the absorption take place in the digestive system?
Answer
Most of the absorption of food takes place in the ileum of the small intestine.
What is the role of the large intestine in digestion?
Answer
Major function of the large intestine. The major function of the large intestine is to absorb water from the remaining indigestible food matter and transmit the useless waste material from the body.
How do digestive tracts differ with differing animal diets?
Answer
Digestive systems take many forms. There is a fundamental distinction between internal and external digestion. External digestion is more primitive, and most fungi still rely on it.[2] In this process, enzymes are secreted into the environment surrounding the organism, where they break down an organic material, and some of the products diffuse back to the organism. Animals have a tube (gastrointestinal tract) in which internal digestion occurs, which is more efficient because more of the broken down products can be captured, and the internal chemical environment can be more efficiently controlled.[3]
Some organisms, including nearly all spiders, simply secrete biotoxins and digestive chemicals (e.g., enzymes) into the extracellular environment prior to ingestion of the consequent “soup”. In others, once potential nutrients or food is inside the organism, digestion can be conducted to a vesicle or a sac-like structure, through a tube, or through several specialized organs aimed at making the absorption of nutrients more efficient.
Describe respiration in plants and the role the stomata play.
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Describe the anatomy of the leaf.
Answer
The leaf is the primary photosynthetic organ of the plant. It consists of a flattened portion, called the blade, that is attached to the plant by a structure called the petiole. Sometimes leaves are divided into two or more sections called leaflets. Leaves with a single undivided blade are called simple, those with two or more leaflets are called compound.
The outer surface of the leaf has a thin waxy covering called the cuticle (A), this layer’s primary function is to prevent water loss within the leaf. (Plants that leave entirely within water do not have a cuticle). Directly underneath the cuticle is a layer of cells called the epidermis (B). The vascular tissue, xylem and phloem are found within the veins of the leaf. Veins are actually extensions that run from to tips of the roots all the way up to the edges of the leaves. The outer layer of the vein is made of cells called bundle sheath cells (E), and they create a circle around the xylem and the phloem. On the picture, xylem is the upper layer of cells (G) and is shaded a little lighter than the lower layer of cells - phloem (H). Recall that xylem transports water and phloem transports sugar (food).
Within the leaf, there is a layer of cells called the mesophyll. The word mesophyll is greek and means “middle” (meso) “leaf” (phyllon). Mesophyll can then be divided into two layers, the palisade layer (D) and the spongy layer (F). Palisade cells are more column-like, and lie just under the epidermis, the spongy cells are more loosely packed and lie between the palisade layer and the lower epidermis. The air spaces between the spongy cells allow for gas exchange. Mesophyll cells (both palisade and spongy) are packed with chloroplasts, and this is where photosynthesis actually occurs.
Epidermis also lines the lower area of the leaf (as does the cuticle). The leaf also has tiny holes within the epidermis called stomata. Specialized cells, called guard cells (C) surround the stomata and are shaped like two cupped hands. Changes within water pressure cause the stoma (singular of stomata) to open or close. If the guard cells are full of water, they swell up and bend away from each other which opens the stoma. During dry times, the guard cells close.
How do the stomata function?
The stomata are located on the leaves. They’re involved witht eh
How is gas exchange accomplished in animals?
Answer
Describe respiration in earthworms.
Earthworms breathe through their skin. Beneath their skin are capillaries that release CO2 and take in O2. They have to move out of the soil to breathe. Under soil with lots of H20 will make them drown. We can see a close association between respiratory and circulatory systems.
Describe respiration in fish.
- Fish get their oxygen through their gills.
- Gills have capillaries that release CO2 and absorb O2 and they also are highly folded which increases the surface area allowing more absorption of O2.
- Gills are protected by a flap of skin called operculum.
- HOW: Fishes open their mouth to let water flow in , the operculum ejects outward so water can flow over the gills where O2 is recieved.
- Fish breathing: http://youtu.be/XEIRlw5rCUk
- Fish in stagnant water have larger gill surface areas. Fish need O2 in water. Ocean waves oxynegate the water for fish whereas smaller ponds don’t so you won’t see a large fish population.
- Inside gill arch with blood vessels and gill filaments O2 exchange happens
- Important feature: O2 rich blood and O2 poor blood flow opposite of eachother over the Lamelia. Counterflow makes sure there’s always diffusion occuring.
Describe respiration in beetles.
- Beetles do not have a central lung repsiratory system and no capillaries
- Instead, beetles have tracheae reinfored with chitin and air tubes along their exoskeleton
- Tracheae is like a vaccuum cleaner that sucks air in chitin are like the ridges of the vaccuum.
- Trachae branches into tracheoles (not reinforced by chitin)
- Air enters through spiracles on the abdomen
- Muscles contract to suck air in
- Efficiency: Have an individual delivery system for muscle and tissue cells that need it.
- Closed tubes have H20 at the end.
Describe respiration amphibians.
- Amphibians have tiny lungs
- They need H20 to breathe
- Use skin surface as a secondary respiration organ in addition to lungs
- They keep their skin moist to absorb dissolved O2
- Have a hard time breathing through nostrils b/c they have no diaphragm. They have to open mouth cavity and close nostrils to force air in.
- http://www.brown.edu/Departments/Engineering/Courses/En123/MuscleExp/Frog%20Respiration.htm
Describe respiration in reptiles.
- Reptiles have highly folded lungs = large surface area; very complex
- Water proof skin so just give them drinking water
Describe respiration in birds.
- One way flow respiration/circular breathing
- Can get 5% more O2 with each breath compared to humans
- Air sacs fill on inhalation
- Air sacs empty on exhalation but lungs fill
- They have: Anterior and posterior air sacs, trachea (where air enters and leaves), and lungs that have air tubes
Define the terms conducting and gas exchange systems. (For the human respiratory system):
- The Conducting System- brings air into lungs (moist surface)
- The Gas Exhange system- gas exhange with the circulatory system
* Large enough to give to cell’s mitochondria
- Trachea has cartillage thats u-shaped
- Lots of surface area on alveoli = more O2
- Thin layer of H20 on alveoli
- O2 rich blood and poor blood vessels attach to alveoli
- Blood capillaries on alveoli
How are the lungs protected?
- Nasal Cavity and trachea filters and gets rid of large particles before it hits the lungs
- NOSE-Mucus collects debris including invading viruses
- TRACHEA-Cilia (hair on cells) moves invaders up to the pharynx area where they are redirected to move down the esophagus to get destroyed by stomach juices.
- Cilia is sticky to catch bacteria and dirt
- Lots of mucus is created to protect lungs from bacteria going in lungs
Describe how the surface of the lung is increased?
- Alveoli increases lung surface area by around 75 square meters (80 times the area of skin)
- Diffusion occurs because alveoli and capillaries surrounding them are only one cell thick (not a thick barrier)
- Continual branching! Trachea to bronchi to bronchioles to alveoli (gas exchange)
Describe inhalation and exhalation.
- Inhalation-AIR sucked IN Diaphragm contracts and moves down and rib cage expands (increase)
- Exhalation-AIR pushed OUT Diaphragm relaxes and moves up and rib cage shrinks (decrease)
- Breathing means an alternation of the two
What is the difference between positive and negative pressure breathing?
Negative pressure breathing sucking air into the lungs (?) and air being pushed out of the lungs (i.e. humans when diaphragm decreases and relaxes)
Positive pressure breathing is gulping/forcing air into the lungs to improve pressure issues. (i.e. Frogs will push air in and close their nasal passage, their thorax will expand and they’ll swallow air into their trachea down to their lungs).
Where are the breathing control sensors and what do they monitor?
- Medulla Oblongata is found at the lowest part of the brain near brain stem and monitors CO2 levels
http: //brainmadesimple.com/medulla-oblongata.html - CO2 levels are monitored via pH
- Sensors near heart monitor CO2 levels
Describe hemoglobin and how it functions. How does it superload the blood with oxygen?
- Structure:
- Quartenary Structure meaning 4 polypeptide chaings
- Each chain has a heme group
- In the center of the heme group is an Fe
- Uses cooperative binding (when one binds theres a change so the next one will bind easier)
- It lowers conc. of O2 next to lungs when it binds to an O2 itself-WHY?
- B/c it plays a trick on the system by changing the identity of O2 to being an oxyhemoglobin so the body thinks it has a low concentration of O2 in the plasma so diffusion will occur into the plasma
- Therefore this allows blood to carry 70 times more O2 aka SUPERLOADINGTHE BLOOD with O2
- Heme group will being to Carbon Monoxide which can lead to problems
What happens with carbon monoxide?
The heme group will bind tightly with carbon monoxide (CO).
http://www.cdc.gov/co/faqs.htm
Red Blood cells/heme group will bind to CO but not enough O2, this will cause cherry red cheeks and fingers and can leave a person poisoned to death.
This is why fireman carry pure O2 tanks to keep from breathing CO. CO will not let go of hemoglobin and will take the place of O2.
Describe the human heart and the role of each of the chambers in circulation.
Answer
Exploring the Heart - The Circulatory System!: http://youtu.be/-s5iCoCaofc
Circulatory System Bill Nye on the Heart (Part …: http://youtu.be/GbttJ-5do9M
Circulatory System Bill Nye on the Heart (Part …: http://youtu.be/RiYOuI7iyp8
