Shark embryo, Squalus acanthias FundamentalsofBiology

What does it mean to be alive?? You may find that your definition, or view, of life differs radically from your neighbor’s. You wouldn’t be alone there. Most scientists can’t agree on it either! Today’s material will cover the basics of biology.

What Scientists Do Agree Upon Life uses energy for metabolism Life maintains itself (homeostasis). Life grows Life reproduces Life reacts to changing conditions Life finds a way!!

What does it take? If you are trying to determine what it takes to be alive what would you do? Water would be a good starting point. Most organisms are composed largely of water.

Where to go next? Organic molecules also play a major role in life processes. Organic molecules are those which contain a source of carbon (except CO 2 which is still considered inorganic), hydrogen, and oxygen.

Which of the following is NOT a class of organic molecules? A.Lipids B.Hydrogens C.Carbohydrates D.Nucleic Acid E.Proteins

What is an example of “Synthesis” and “Breakdown” in organisms? A.Polymerization and decription B.Monomers and polymers C.DNA and RNA D.Photosynthesis and Glycolysis E.Respiration and chemosynthesis

Just imagine how much energy is stored in this whale blubber (fat).

…and even antifreeze!

How are proteins synthesized? A.Ribosomes assemble amino acids by “reading” RNA B.Mitochondria use ATP to create proteins C.Proteins are made by lysosomes using instructions from DNA

Crash course- biological molecules

Other necessities… In addition to proteins, carbs., and lipids, organisms rely on DNA, RNA, and ATP to transfer genes, build proteins, and store energy, respectively. ATP is extremely important because it serves as “energy currency” for most cells.

ATP BioVid- ATP

Most energy used by organisms originates from photosynthesis.

An example of a structural carbohydrate is… A.ATP B.RNA C.Chitin D.Glucose

Photosynthesis Crash Course- Photosynthesis

Photosynthesis respiration Photosynthesis makes it and respiration takes it!! Each process is essentially the reverse of the other.

Photosynthesis and respiration combine to facilitate primary production. Primary producers are photosynthetic organisms for the most part. Each relies on Nitrates (NO3-1), phosphates (PO4-2), and occasionally silica (SiO2).

Which of the following organisms is an example of a producer? A.Clownfish B.Algae C.Snails D.Nitrifying Bacteria E.Foxface Rabbitfish

Crash Course- Glycolysis

Cells, or the basic unit of life, contain a nucleus, and various cellular organelles which carry out cell specific functions. In addition to the organelles listed certain bacteria also contain motility structures called flagella or cilia.

Sometimes, all you need in life is one cell, especially if you’ve got 10,000 buddies just like yourself!!

Challenges to life!

Introduction Maintaining steady-state equilibrium in the internal environment of aquatic and marine organisms is challenging. Much is done involuntarily (hormones, enzymes, osmoregulation, etc.) so little physical action is required, however… “Pick-up-and-move” still an option! (Poor environment.)

Definitions Homeostasis = maintaining steady state equilibrium in the internal environment of an organism Solute homeostasis Solute homeostasis = maintaining equilibrium with respect to solute (ionic and neutral solutes) concentrations (i.e. salts) Water homeostasis = maintaining equilibrium with respect to the amount of water retained in the body fluids and tissues

Osmoregulation in different environments Challenge to homeostasis depends on – Solute concentration of body fluids and tissues – Concentration of environmental solutes marine: ~34 ppt salinity = 1000 mosm/l freshwater: < 3 ppt salinity = mosm/l

Diffusion video

Osmoregulation in different environments Each species has a range of environmental osmotic conditions in which it can function: – stenohaline - tolerate a narrow range of salinities in external environment – euryhaline - tolerate a wide range of salinities in external environment short term changes: estuarine ppt, intertidal long term changes: diadromous fishes (salmon)

Four osmoregulatory strategies in fishes 1. Isosmotic ( nearly isoionic, osmoconformers ) 2. Isosmotic with regulation of specific ions 3. Hyperosmotic (fresh H 2 0 fish) 4. Hypo-osmotic (salt H 2 O fish)

Ions naturally flow from areas of low concentration to areas of high concentration. A.True B.False

A marine osmoconformer placed into fresh water would shrink due to osmotic water loss. A.True B.False

Osmoregulation Strategies Osmoconforming (no strategy) Hagfish internal salt concentration = seawater. However, since they live IN the ocean....no regulation required!

Osmoregulation Strategies Elasmobranchs (sharks, skates, rays, chimeras) – Maintain internal salt concentration ~ 1/3 seawater, make up the rest of internal salts by retaining high concentrations of urea & trimethylamine oxide (TMAO). – Bottom line…total internal osmotic concentration equal to seawater! – How is urea retained? Gill membrane has low permeability to urea so it is retained within the fish. Because internal inorganic and organic salt concentrations mimic that of their environment, passive water influx or efflux is minimized.

– ionic conc. approx. 1/3 of seawater – drink copiously to gain water – Chloride cells eliminate Na + and Cl - – kidneys eliminate Mg ++ and SO 4 = advantages and disadvantages? Osmotic regulation by marine teleosts

Saltwater teleosts: Na +, Cl - chloride cells Mg ++, SO 4 = kidneys

A molecule that speeds up a chemical reaction is called…? A.Lipid B.Enzyme C.Hormone D.Deoxyribonucleic Acid

Which of the following is NOT included in the 5 kingdom system? A.Viruses B.Bacteria C.Fungi D.Multicellular Seaweeds

Which is the correct arrangement of biological taxa? A.Kingdom-Phylum-Class-Order… B.Kingdom-Class-Phylum-Order… C.Class-Phylum-Order-Family… D.Phylum-Order-Class-Family…

Thermoregulation in Fishes

Thermoregulation video

Temperature is always an issue.

A.True B.False Unlike mammals, no fishes can maintain body temperatures different from that of the surrounding environment.

Fish are conformers (well, sort of...) Body temperature is that of the environment (poikilothermic ectothermy) Each species has particular range of temperatures that they can tolerate and that are optimal Big difference!

Behavioral Thermoregulation in Fishes Although fish are ectotherms, they can alter their body temperature by moving to habitats with optimal temperature Some fish can maintain body temperature greater than ambient - tunas, billfishes, and relatives (they are nearly endothermic)

Hot Fishes Billfishes have warm brains – excess heat production from muscles around eye

In photosynthesis, A.carbon dioxide and water are used to produce glucose. B.glucose is broken down into carbon dioxide and water. C.energy stored in organic matter is transferred to ATP. D.carbon is converted to an inorganic form.

Budding in coral allows multiple replications of the same entity. Since coral uses itself as a template, this is a form of asexual reproduction.

The direct function of genes is to A.code for a trait, such as blue eyes. B.allow natural selection to proceed. C.specify the order of amino acids in one protein. D.make perfect copies of each strand of DNA.

Rhizomes (runners) sent from sea grass is another example of asexual reproduction.

Meiosis v. Mitosis video

Sexual reproduction: Union of two gametes.

Reproductive strategies may involve mass production of young…like this jawfish. Advantages??? Disadvantages???

Single offspring with a high degree of parental care

Meiosis Crash course- Meiosis

Next time…real animals and real names.