1. Transition to Land Biomes
AP Biology
Transition to Land Biomes

2. 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

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

4. What controls the expression of genes in an organism?
Enzymes

5. 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

6. 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

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

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

9. 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

10. 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)

11. 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

12. 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

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

14. 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

15. 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

16. 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

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

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

19. 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

20. 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

21. 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

22. 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

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

24. 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

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

26. 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

27. 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

28. 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

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

30. What are endotherms?
Organisms that maintain their own internal heat

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

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

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

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

35. 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 •

38. Hadley Cell Model

39. Meristematic Tissues

40. Darwin’s experiment on Phototropism

41. Phytochrome activation

42. Signal Transduction Response

43. Long night plants

44. Short night plants

45. Transpiration

46. Guard Cell operation

47. Amino Acid structure (Remove the amine on the left)

48. Nitrogenous Waste forms

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

50. 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.

51. 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