BSC 2011

Fall 2007

Dr. Herrera

• BSC 2011 Integrated Principles of Biology II• Fall Semester 2007• Section 6992: Period 10• Lecturer: Dr. J. C. Herrera, Zoology• Office: 3175 McCarty Hall A• Office Hours: TWTh 2nd period until 9/27, after which time they will

change, and by appointment• Phone: 213-2498, Email: herrera@zoo.ufl.edu• Discussion Leader: • Office: Silvia Lomascolo• Email: slomascolo@zoo.ufl.edu• Office Hours: TBA• Course Home Page: http://nersp.nerdc.ufl.edu/~herrera/bsc.html • Additional Help: • Core Biology Office: Tangelyn Mitchell, 210 Carr Hall, 392-1565 • Coordinator of Biological Sciences: Dr. Kent Vliet, 392-1566 • Email:

kent.vliet@zoo.ufl.edu

• Lectures• Tuesday, Wednesday, Thursday, 10th Period (5:10pm). McCarty C

100 (MCC 100)• Discussions• Friday, 10th Period. MCC 100; May include lectures as needed.• Textbook• Campbell, et al., 7th Edition, "Biology"; you are responsible for using

the correct edition. “Copies on Reserve at the Marston Science Library - Ask at the circulation desk.”

• Examinations: All machine-graded exam questions must be answered with a #2 pencil. NO MAKE UP EXAMS WITHOUT PRIOR PERMISSION. In case of illness, a note from your physician is required. A personal matter requires a note from the Dean of Students (P202 Peabody Hall). ANY MAKE UP EXAMS MAY BE IN AN ESSAY FORMAT. Each lecture exam is worth 175 points. Total points possible = 700. Grade is based on the student's total score relative to the class curve and class mean. NO EXTRA CREDIT IS ALLOWED. Exams are not cumulative.

• Academic Honesty: The Honor Code reads: “We, the members of the University of Florida community, pledge to hold ourselves and our peers to the highest standards of honesty and integrity”. You must sign your exam papers to confirm that you neither gave nor received unauthorized aid in taking the exam.

• EXAMS WILL BE GIVEN ON THE FOLLOWING DATES. ATTENDANCE IS MANDATORY.

• Exam I: Friday, September 14, In Class Period – McCarty C 100 (MCC 100)• Exam II: Friday, October 12, In Class Period - McCarty C 100 (MCC 100)• Exam III: Friday, November 9, In Class Period – McCarty C 100

(MCCC100)• Exam IV: -- Sec. 6992 (10th period): December 10, 8:00 – 9:00 PM

Location: TBA• Many students experience test anxiety and other stress related problems.

“Self help guides for students are available through the Counseling Center (301 Peabody Hall, 392-1575) and at their website: http://www.counsel.ufl.edu

• Stress: For students with test anxiety or stress-related problems, self help guides are available at the Counseling Center, 301 Peabody 392-1575, and at www.counsel.ufl.edu http://www.counsel.ufl.edu/.

• Note: Attendance is required. “Makeup” notes are not available. You are expected to be in class. You are responsible for all announcements made in lecture and/or posted on the class webpages. Exam issues may be addressed for one week only after each exam. You may not review previous exams, other than the final, after the semester has ended. Challenges to exam questions must be submitted in writing. Scantrons are not available for individual student review. There is no extra credit. Please do not request individual special treatment at the end of the semester because we do not adjust grades for individuals for ANY reason. Plan to do well on all exams from the beginning of the semester. All email correspondence must be from your ufl.edu account, must have your full name in the body of the email, and in the subject line you must identify the course in which you are enrolled. Emails not meeting these requirements may not be answered.

• What is the relevance of science to your own life? We introduced the course last semester by listing some of the current issues, in the news today, with which science helps us understand, cope with, and/or make decisions about our world. Common topics of concern often include:

• Stem cell research• Cloning• Biological warfare• Global warming• Pollution

Biology = the study of life

Properties of life:

• Review some of the basic properties of life. Review your notes from last semester or take a look at Chapter 1.

• Much of 2010 is about mechanisms for maintaining homeostasis, the workings of the cell and the physiology of larger organisms.

• More than half of 2011 concerns genetics. Genes contain all the information to build even complex organisms and code for all the chemistry and structure necessary for physiological processes. We will talk about the cellular basis of reproduction, how genes are passed from parent to offspring, and how genes control physiology.

• The rest of the course covers evolution, which at its simplest level is a change in gene frequency (genetics again) and ecology, looking at biology on larger scales than just individual organisms. We will discuss populations, communities and ecosystems.

I. All life is based on the cell:

A. The cell: the fundamental unit of life.

• Cell Theory • 1. all living things are made of cells • 2. all cells arise from other cells • 3. a cell can divide, to form new cells

-----The ability of cells to divide is the basis of reproduction, growth, development, maintenance and repair.

B. What is a cell?

• 1. All cells are bound or enclosed by a membrane

• 2. All cells contain DNA at some stage in their lives (e.g., a red blood cell eventually loses its DNA at maturity)

C. There are two major types of cells:

• 1. Prokaryotic cells• a. bacteria and blue green algae (cyanobacteria) only • b. have no internal membrane-bound organelles • c. nearly all have cell walls

• 2. Eukaryotic cells • a. all other forms of life • b. subdivided by internal membranes into organelles • c. have chromosomes organized within a nucleus • d. may (e.g. plants) or may not (e.g., animals) have a

cell wall

D. The ability to reproduce is characteristic of living things, and this ability has a cellular basis.

• 1.  All cells arise from preexisting cells. Cells divide to form new cells.

• 2.  Cell reproduction:  In the cell cycle, a cell duplicates its contents, and then divides in two. The two main phases of the cycle are interphase and "m"-phase which includes mitosis (division of the nucleus) and cytokinesis (division of the cytoplasm).

II. The Roles of Cell Division

• 1.   Unicellular organisms: reproduces an entire organism.

100 µm

(a) Reproduction. An amoeba, a single-celled eukaryote, is dividing into two cells. Each new cell will be an individual organism (LM).Figure 12.2 A

A. Reproduction, growth, development and repair

• 2.   Multicellular organisms: reproduction, plus cell division allows:

• a.   Growth and development from the fertilized egg (zygote)

• b.   Maintenance and repair

20 µm200 µm

(b) Growth and development. This micrograph shows a sand dollar embryo shortly after the fertilized egg divided, forming two cells (LM).

(c) Tissue renewal. These dividing bone marrow cells (arrow) will give rise to new blood cells (LM).

Figure 12.2 B, C

• 3.  Cell division: the distribution of identical hereditary material (DNA to two daughter cells.

• The cell:

a.  Precisely replicates DNA b.  Allocates the two copies of DNA to opposite ends of the cell c.  Separates into two daughter cells

B. Distribution of identical sets of chromosomes to daughter cells

• 1.  The genome: total set of genes in a cell of a particular species

The genomes of bacteria are small, while the genomes of other species are larger.

2.  Chromosomes: allow the duplication and distribution of the large genomes of eukaryotes.

50 µm

Figure 12.3

• 3.  Eukaryotic Chromosomes: supercoils of  DNA-protein complex (chromatin). Each chromosome has:

• a.  A single, long, molecule of DNA, segments of which are the genes. b.  Various proteins which maintain the structure of the chromosome or are involved with the expression of genes, DNA replication, and DNA repair

• 4.  Each species: has a characteristic number (e.g., human somatic cells have 46); gamete cells (sperm or ova) have half the number of chromosomes of somatic cells (e.g., human gametes have 23)

• 5.  Chromosomes: are in different states at different stages of the cell cycle.

• a.  Interphase:  loosely folded; not visible.

• b. Mitotic phase: highly folded and condensed; visible with a light microscope (basis of karyotype)

6. The genome is duplicated: for cell division. Now, each chromosome =  two sister chromatids attached at the centromere.

0.5 µm

Chromosomeduplication(including DNA synthesis)

Centromere

Separation of sister

chromatids

Sisterchromatids

Centromeres Sister chromatids

A eukaryotic cell has multiplechromosomes, one of which is

represented here. Before duplication, each chromosome

has a single DNA molecule.

Once duplicated, a chromosomeconsists of two sister chromatids

connected at the centromere. Eachchromatid contains a copy of the

DNA molecule.

Mechanical processes separate the sister chromatids into two chromosomes and distribute

them to two daughter cells.

Figure 12.4

III. Cell division (M phase) has two steps: mitosis and cytokinesis.

A.  Mitosis – nuclear division - sister chromatids pulled apart into two sets of chromosomes, one at each end of the cell.

B.  Cytokinesis – division of the cytoplasm into two separate daughter cells, each containing 1 nucleus with 1 set of chromosomes.

• 1.  Animal cells - cytokinesis = "cleavage" • 2.  Plant cells - cytokinesis by cell plate

formation, a cell wall forms from the cell plate.

• Not all cells undergo cytokinesis following mitosis.

Figure 13.5

Key

Haploid (n)

Diploid (2n)

Haploid gametes (n = 23)

Ovum (n)

SpermCell (n)

MEIOSIS FERTILIZATION

Ovary Testis Diploidzygote(2n = 46)

Mitosis anddevelopment

Multicellular diploidadults (2n = 46)

IV. Human Life Cycle Adult inherits 46 chromosomes

Meiosis in gonads halveschromosome number

Sperm cell (23 chromosomes)Ovum (23 chromosomes)

Fertilization restores thechromosome number to 46

Zygote (46 chromosomes)

Mitosis produces genetically identical daughter cells. Mitosis is responsible for growth and development into an adult, plus cellular repair.

• Note: chromosome, chromatid, chromatin – this course includes several sets of words which are very similar – be sure you know the differences among each set of similar words.