PLSC 161 Final Exam Review

1. Do plants have the same scientific name in other countries?

a. Yes, derived from Latin or Greek roots

2. What is biological nitrogen fixation? Where does it occur and what organisms are involved?

a. Biological nitrogen fixation is the conversion of N2 -> NH3 by legume plants!

i. Nitrogen fixation happens in the nodules of legumes

ii. From the nodules creates a rhizobium bacteria

iii. Rhizobium bacteria creates the NH3

3. Why is the stomata important for plant health?

a. The stomata is important because it creates respiration, transpiration, and photosynthesis

b. Stomata: natural microscopic openings

i. In photosynthesis: involved in gas exchange, lets in CO2 and O2 leaves

ii. Respiration: o2 -> co2

iii. Transpiration: guard cells regulate the opening and closing and let in water

c. Accounts for < 1% of leaf surface area

d. >90% water transpiried

4. What is a plant hardiness zone?

a. Graph, table, or map that shows what would grow well in the certain area. It is created by the USDA

5. What is required for all seeds to germinate and what is the first structure to appear?

a. Moisture/water

b. Oxygen

c. Temperature

6. What is an example of an abiotic disease?

a. Iron deficiency, natural disasters, etc.

7. What are the three weed distribution patterns?

a. Random

b. Regular: least likely seen

i. From contaminated seed

c. Patchy: associated with perennials

i. Rhizomes: below

ii. Stolons: above

8. What is a perfect flower?

a. Has to include all of these parts:

i. Stigma

ii. Style

iii. Ovary

iv. Ovules

v. Stamen

vi. Anther

vii. Filament

9. What is the dormant state for insects called?

a. diapause

10. What is a dicot (provide an example)?

a. 2 cotyledons

i. soybean or peanut

b. Broadleaf plants

11. What percent of weeds are native to North America?

a. 40%

12. What is a lichen?

a. Symbiotic relationship of 2 organisms alge and fungi

i. Alge provides carbohydrates

ii. Fungi provides protection

13. Do plants with bright colors have lightweight pollen?

a. No

i. brighter the flower is, the more dependent that they are on pollinators

14. Compare and contrast epigeal and hypogeal emergence.

a. Epigeal: above emergence,

i. soybean

b. Hypogeal: below emergence

i. Pea

15. What is usually desired when domesticating a plant?

a. Wild species are more likely to shatter

b. Flowers at the same time=same time harvest

c. Higher germination rate

d. Bred out dormancy

16. What is a vascular system in plants?

a. Vascular tissue:

i. Xylem: water

ii. Phloem: sugar and carbs

17. Where would you go to find a plant species greatest biodiversity?

a. Center of origin

b. Pest: also center of origin

18. Draw, label and describe the disease triangle for the Irish Potato Famine.

a. BC

b. A: environment

i. Cool and wet

c. B: virulent pathogen

i. Phytophthora infestans aka late blight

d. C: Host

i. lumper

19. What does IPM stand for?

a. Integrated pest management

20. What do weeds take away from crops?

a. Light

b. Water

c. Nutrients

d. Space

21. What type of seeds would you most likely “save the seeds” to plant in future years?

a. Hybrid: cannot be saved

i. Doesn't withhold genetic integrity

ii. why do we grow hybrid?

1. Higher yield

2. Vigor

b. Answer: variety/cultivar

22. What is a nematode?

a. Unsegmented roundworm

b. The most abundant microcellular organism on earth

c. Good; they eat bacteria

23. What do most nematodes feed on in the soil?

a. bacteria

24. What are some advantages to growing hybrid seed?

a. Vigor/uniformity

25. What is the difference between germination and emergence?

a. Germination: formation of the radicle

b. Emergence: epigeal or hypogeal

26. How much can landscape plants add to the value of your home?

a. 15% of home value

27. Compare and contrast annual and perennial flowers.

a. Annual:

i. sees to sees in 1 year

ii. grow quicker

iii. longer bloom/flowing peroids

iv. used for cut flowers

b. Perennial:

i. Flower for 1-2 weeks

ii. Propiagting: rhizomes and stolons

1. Stolon: strawberry

2. Rhizomes: Canada thistle

28. What is the difference between a pathogen and a disease?

a. Pathogen: no host, scientific name

b. Disease: has a host

29. What crops require pollination?

a. Coffee, fruits, berries, nuts

b. Anything that has a bright flower

30. Where does photosynthesis occur?

a. Mesophyll layer

i. Mesophyll cells: contain chloroplasts

ii. Can occur on stems

31. How does temperature influence photosynthesis?

a. Bell curve shape represents the relationship between temperature and the rate of photosynthesis, where optimal temperatures yield the highest rates, while extreme temperatures can inhibit enzyme activity and reduce overall efficiency.

b. As temperatures rise beyond the optimal range, the rate of photosynthesis may decline due to denaturation of proteins and disruption of metabolic processes.

32. Where do trees get their biomass from?

a. Atmosphere through photosynthesis

33. What influences nitrogen fixation?

a. Healtiness of the plant

i. Determined by:

1. Light

2. Water

3. Nutrients

4. Space

b. Length of growing system

34. How do plants decompose?

35. Why do damaged trees have more lichens?

a. Lichens do not have to compete with the live tree to create photosynthesis

36. Compare and contrast natural selection and artificial selection.

a. artificial selection: selection made by humans

b. Natural selection: selection made in natural ways

37. Compare and contrast winter annual weeds and summer annual weeds.

a. Winter: Actively grow when least amount of competition and greatest amount of water

b. Summer: grows at different time during the season

38. What influences a plant’s phenotype?

a. Genotype and environment

39. How would you differentiate SCN from a nodule?

a. SCN is made up of cysts of eggs while nodules are apart of the plant

40. What is pH and how does it influence plant health?

a. Soil pH is the measure of how alkaline or acidic a soil is, and pH has a large impact on plant health and growth. The more normal the pH is the better the health of the plat will be.

41. Do wild species germinate more uniformly as compared to domesticated ones?

a. No

42. What does the USDA stand for?

a. United States Department of Agriculture

43. What is one goal of breeders when creating crops with enhanced root biomass?

a. Larger leaves to create more photosynthesis

44. Compare and contrast photosynthesis and respiration.

a. Photosynthesis: CO2->O2

b. Respiration: O2 -> CO2

45. What is meristematic tissue?

a. meristematic regions

i. rapid cell division

ii. root cap, apical, axillary