Transition to Land Biomes AP Biology Transition to Land Biomes

What is the main material in all life forms? Water Because life is mostly made of water, all life forms will be greatly affected by….. Sunlight intensity

Why is water so important to life and to the earth? It regulates temperature

What controls the expression of genes in an organism? Enzymes

What is the ultimate source of energy for the earth? Sunlight What are some of the functions of sunlight? Powers photosynthesis Keeps the earth warm Determines the types of biomes

What actually causes the Hadley cells to form? Intensity of sunlight Wind patterns Where is light intensity greatest? At the equator What results from this? Massive evaporation of water from oceans

How is the light intensity in the polar regions? Much less, so there is very little evaporation

Why are the tropics considered to be mainly deserts? High light intensity Little water availability High evaporation

What happens to sunlight during photosynthesis? The process of photosynthesis converts the sunlight energy into energy stored up in the chemical bonds of carbohydrates C6H12O6

What is another way that sunlight affects plants? It directs plant growth What is auxin? A growth hormone released by plants Where is it released? From the meristems (the tip end of the shoots)

How does auxin affect a plant? It travels down the dark side of the plant This makes the cells on that side elongate Unequal growth occurs when one side grows faster than the other The plant begins to bend toward the side that is slower in growing If it is bending toward the side that is getting light, then it is bending toward the light

What is phototropism? The growth of or the movement of an organism toward light What does “photo” mean? Light What does “tropism” mean? Turning movement or growth in response to a stimulus

Who was the first person to recognize and describe phototropism? Charles Darwin

What causes flowering to occur in plants? The absence of sunlight What determines flowering? Genetics and protein/enzyme activation What are these proteins called? Phytochromes What is their function? To act as biological clocks

How is the Signal Transduction Pathway involved in the activity of plants? Sunlight causes a shape change in the receptor protein The shape change allows the activation of transcription and translation of genes These genes give instruction for making some of the leaves into flowers This is accomplished by adding different reflecting pigments to the cells, which changes their color

What are long-night flowers? Plants that require long, uninterrupted periods of dark in order to flower These plants usually flower in the fall or winter

What are short night flowers? Plants that require short periods of dark in order to flower

What is the critical limit? The duration of night (amount of dark) needed in order for the plant to flower

What is transpiration? Water loss by plants through the stomata in the leaves How is transpiration controlled? By the guards cells What controls the guards cells? The phytochromes and potassium ions

Why don’t the stomata stay closed all the time in order to prevent water loss? They have to be open for carbon dioxide to come in What is the continuous battle for plants? Letting enough carbon dioxide in, while preventing too much water loss

What causes the differences between C3, C4, and CAM plants? The types of environments and water availability What influences transpiration rate? Light intensity Wind Humidity

What is osmoregulation? The control of water loss in animals Why is osmoregulation important? All organisms must maintain homeostasis in order to live What is required for homeostasis? Large amounts of energy

What are some things that will remove water from animal cells? Sweating Panting Breathing Waste removal Carbon dioxide oxygen

What must be removed from animals in order to keep them from dying? Ammonia How is the ammonia produced? During the process of cellular respiration when amino acids are broken down What is this process called? Deamination

How do fish get rid of the ammonia? They release it directly into the water

How do birds and reptiles get rid of the ammonia? They change it to uric acid, which is a paste-like substance that does not require too much water

How do mammals and amphibians get rid of the ammonia? They change it into urea, and then dilute it with lots of water, which is then called urine

Besides causing a loss of water, what do sweating and panting do for the organism? They help to cool the organism Water acts as a heat “trapper”, so removing the water takes heat away

What is evaporative cooling? Air movement removing water as it evaporates

What are endotherms? Organisms that maintain their own internal heat

What are ectoderms? Organisms whose body temperature conforms to the temperature of their environment

What is counter-current heat exchange? Transferring heat from within the body to outer parts of the body through the blood

What are ways body temperature can be increased? Shivering and metabolism

What is thermoregulation? Control of heat within an organism What accomplishes this control? Hypothalamus

endotherm vs. ectotherm How is heat lost by different organisms? Through moist surfaces Fish – gills Amphibians – skin Mammals - lungs one-celled amphibians echinoderms insects fish mammals endotherm vs. ectotherm size cilia water vs. land •

Hadley Cell Model

Meristematic Tissues

Darwin’s experiment on Phototropism

Phytochrome activation

Signal Transduction Response

Long night plants

Short night plants

Transpiration

Guard Cell operation

Amino Acid structure (Remove the amine on the left)

Nitrogenous Waste forms

Countercurrent Heat Exchange Canada goose Pacific bottlenose dolphin Blood flow Artery Vein Vein Artery 35°C 33° 30° 27° 20° 18° 10° 9°

Internal body temperature Temperature control Thermostat in hypothalamus activates cooling mechanisms. Sweat glands secrete sweat that evaporates, cooling the body. Blood vessels in skin dilate: capillaries fill with warm blood; heat radiates from skin surface. Increased body temperature (such as when exercising or in hot surroundings) Body temperature decreases; thermostat shuts off cooling mechanisms. Homeostasis: Internal body temperature of approximately 36–38°C Body temperature increases; thermostat shuts off warming mechanisms. Decreased body temperature (such as when in cold surroundings) Blood vessels in skin constrict, diverting blood from skin to deeper tissues and reducing heat loss from skin surface. Thermostat in hypothalamus activates warming mechanisms. Skeletal muscles rapidly contract, causing shivering, which generates heat.

Gas Exchange in Many Forms… one-celled amphibians echinoderms insects fish mammals endotherm vs. ectotherm size cilia water vs. land • Endotherms have larger surface area of respiratory surfaces because of their increased metabolic demands. Gills, trachea, lungs