Lecture 1: Intro to Plants, Intro to Science

1. Lecture 1: Intro to Plants, Intro to Science

2. Why do we love plants? What makes them so special? Plants are:

3. People and Plants • We affect each other. – how? • We can’t live without them! • . • . • They can destroy habitat, harming our economy – invasive plants!! • We can alter the course of their evolution, through: • Gm crops, conservation genetics, selective breeding

5. Plants are sources of • food • paper • fibers • Medicine • Chocolate • Sugar • vanilla • cinnamon • pepper • wood • cotton • linen • roses • paper • oxygen

6. THE PROCESS OF SCIENCE • The word science is derived from a Latin verb meaning “to know” • Science is a way of knowing • .

7. The Process of Science: "The Scientific Method"

8. What’s a Scientific Question? • Scientific Questions are….

9. What’s a Hypothesis? • Tentative, but untested explanations • Ex. • Make predictions that can be tested • Predictions written as “If [hypothesis], then……” statements • .tree to grow taller

10. How do you test a Hypothesis? • Via controlled experiments or pertinent observations • All variables must be controlled • Kinds of variables: • Independent variable – • Dependent variable – • Controlled Variables - All other things (variables) that you try to hold constant

11. Experiments of classical design • Individuals studied divided into two groups • Experimental group • Control group • exposed to theidentical conditions as the experimental group, but not be exposed to the independent variable

12. What happens if all of our experiments fail to disprove our hypothesis? • What if workers in other parts of the community, county, state, country, or world also fail to disprove your hypothesis?

13. Theory • We arrive at theories by scientific method

14. To Prove or Not to Prove • Experimentation can either support or reject a hypothesis. • Experimentation can never prove a hypothesis 100% correct. – why? • After each each experiment we need to re-evaluate our results and observations to either make changes in our hypothesis or more likely design a new experiment.

15. Which end of a plant is up?

16. Muscle cell Parenchyma cell Cells Tissues Muscle tissue Dermal tissue Organs Heart Leaves Circulatory system Systems Shoot system

17. Three organs: Roots, stems, leaves • Roots– • Covered with root hairs – increased surface area for absorption

18. Sweet Potato – storage root Modified Roots – Prop roots Aerial strangler roots Buttress roots Pneumatophores

19. 2. Stems/shoots • Two types of shoots • Vegetative – • Reproductive – • Two parts of stem: • Node – point of leaf attachment • Internode – stem segments between nodes

20. Two types of buds • Terminal bud – • Axillary buds – in angle (axil) between leaf & branch, contain meristem with potential to become a vegetative shoot. Mostly dormant. Apical dominance = -remove or depress apical bud, axillary buds begin to grow.

21. Modified Shoots (stems): • Stolons – • Rhizomes – • Bulbs – swollen underground shoots • Tubers – swollen rhizomes Asexual, vegetative propagation Stores food for later growth

23. 3. Leaves – main photosynthesis organs http://www.knotweed.co.uk/japknot_Info.htm

24. Modified leaves • Compound, doubly compound – why??

25. Modified leaves

26. Leaf types: Simple leaf = Compound leaf = divided into distinct units called leaflets

27. Four types of leaf arrangement: • Acaulescent – • Alternate – • Opposite – leaves borne across from each other at the same node • Whorled – 3 or more leaves arising from the same node.

30. 3Each male flower part is called a stamen. The stamen is composed of: 1. Filament – 2. Anther – a collection of pollen sacs that sits on top of the filament.

31. Each female part is called a pistil. Pistil = the female reproductive organ, consisting of: 1. Stigma – 2. Style – 3. Ovary – the base of the pistil, contains the ovules. (Mature ovules are seeds and mature ovary is the fruit)

32. More terms!!! Complete flower = Incomplete flower = lacks one of the above parts

34. Fruit types Fruit = *the primary function of a fruit is seed dispersal