BIS 2A: Introductory Biology: Cell Functions

Professor Terence M. MurphyPlant Biology Department

University of California, Davis

Prerequisites: BIO 1 Text: Rost, Barbour, Stocking, and Murphy, Plant Biology 2nd edn, 2006, Cengage. Web site: general information and help; lecture schedule; lecture pdfs; objectives (what I want you to know from each lecture) plus some sample exam questions. http://www-plb.ucdavis.edu/courses/bis/1C/nlu-w11/index.htm Lectures: Three morning lectures each day (two on exam days). Lectures use PowerPoint slides, and the slides will be on the web site for review.

Discussions: Discussion of issues from lecture, clearing up sticky points;

problems relating lecture to “real” situations (and exam questions).

Topics:

Plant body

Photosynthesis

Roots and respiration

Transport

Growth and development

Reproduction

Ecology

Evolution

Lecture topics (readings in Rost et al., 2nd edn)

First hour Second Hour Third hour Discussion

Monday,

January 10

Introduction (2-10) The Flowering Plant

Body, Cells, Tissues

(29-40; 49-67)

Shoot Primary Growth

(86-90)

Tuesday,

January 11

Photosynthesis (106-

119;146-156)

Photosynthetic

Adaptations to

Environment (156-159)

More Photosynthetic

Adaptations (156-159)

Wednesday,

January 12

Root Structure and

Growth (69-84)

Root Structure and

Mineral Uptake (165-

180)

Cellular Respiration

(133-146)

Thursday,

January 13

Xylem and

Transpiration (165-

180)

Phloem and

Translocation (180-

182)

EXAM (Lectures

through Respiration)

Friday,

January 14

Secondary Growth (90-

104)

Control of Plant

Development:

Hormones (238-253)

Control of Plant

Development: Light

(254-258)

Monday,

January 17

Eukaryote Life Cycles

(184-194)

Angiosperms: Flowers

and Fruits (425-433)

Flower Adaptations

(197-211)

Tuesday,

January 18

Fruits and seeds (215-

234)

Ecology: Energy flow

(449-450)

Midterm Exam 2

(Topics through Flower

Adaptations)

Wednesday,

January 19

Life History Patterns

(450-455)

Population Dynamics

(450-455)

Competition and

Predation (468-484)

Thursday,

January 20

Theories of

Evolution:

Adaptation

Genetic Variation hardy-Weinberg:

Natural Selection

(468-484)

Friday,

January 21

Succession, Diversity,

and Stability (468-484)Biomes of the World

(468-484)

Final Exam (Topics

from Fruits and

Seeds, and

comprehensive)

Final Exam

Tests and grading:

1st Midterm 20% A >85% or >80%ile

2nd

Midterm 20% B >75% or >50%ile

3rd Midterm/Final 40% C >65% or >20%ile

Discussion/T.A. 20% D >50% or >10%ile

Course objectives

Objective 1: expand view of sessile (plant) life style,

physiology (Can I make you see a tree the way I do?)

When I see a tree, I see a structure, twice as big as

what is visible above ground, held together by carbon-

based fiber composite materials (high tech)

When I see a tree, I see a chemical factory. Bathed

in sunlight (2 x 109 J/m2-yr), it converts 1% of the incident energy into high-energy organic compounds

(2 x 107 J/m2-yr). Assuming 300 m2 leaf area, it

produces 6 x 109 J/yr. That is equivalent to the energy needed to drive your scooter over 5600 km

(assuming 42 km/l, 4.5 x 107 J/l octane).

When I see a tree, I see a complex distribution system. High-energy molecules being pumped (non-mechanically) throughout the plant.

When I see a tree, I see a growing organism. Both above and below ground, there are hundreds of growing points. Below ground, these push through soil with a pressure of several atmospheres (up to 100

lbs/in2) yet resist abrasion.

When I see a tree, I see an organism resisting a hostile environment: dry air (sucks 4-15 l/day of water from leaves); parasites (bacteria, fungi, insects, nematodes, mammals); high light, UV, O2 oxidize essential lipids; lack of O2;

cold; heat. Mechanisms of resistance cannot depend on escape.

When I see a tree, I see a sexually reproducing organism--even if not easily visible, this plant has (or will have) flowers and a sexual system that is both similar and different from ours. It may depend on a different species for fertilization; it will include a period of suspended animation (in which plantlet loses 50-90% of its water).

Objective 2: Describe the interactions among

community members

When I see a forest, I see several individual populations

of organisms, changing in number and age distribution

according to the supply of food and the benevolence (or

stress) of the environment; over the long term, adapting

to the stresses and opportunities of the environment.

When I see a forest, I see a flow of matter and

energy from the abiotic environment into living

organisms and back.

...a community of organisms of different species, all

interacting, some preying on others, some

depending on others.

...a community whose most obvious members (the

plants) reveal much about major environmental

processes and determine whether more transient,

mobile members (animals, microorganisms) can

survive.

Objective 3: describe how physiology and ecology interact in evolution When I see a plant (or an animal), I recognize an organism that fits its environment in many ways. ...I see a species whose members will produce more offspring than can all survive, but the “fittest” offspring will survive and reproduce. ...I recognize that it is just one of over 300,000,000 species of organisms that have appeared on (and disappeared from) the Earth.

Life has an origin and a history. That history is reflected in fossils, but also in the physical history of the Earth.

Why so late?

Was global warming good?

Why methane then and not now?

The history of life has led to an amazing diversity of organismsMajor groups of organisms (as defined in the “Five

kingdom system” 60 years ago, using electron

microscopy to differentiate cells):

Prokaryotes (Bacteria, Archaea)—no nucleus,

unicellular and simple multicellular

Protists—eukaryotes, ±multicellularity, ±motility,

±photosynthesis, various life cycles

Plants—eukaryotes, photosynthetic, alternation of

generations (or sporic life cycles)

Fungi—eukaryotes, simple multicellular, non-motile,

haplontic (or zygotic) life cycles

Animals—eukaryotes, consumers, diplontic (or

gametic) life cycles

Our understanding of the diversity of life has expanded and changed, as genetic techniques have been used to differentiate among organisms