Bio-LAB Notes! By PiNoY!

2^nd RELEASE date: 12-7-97

Vocab 2 know:

Cell cycle - a repeating set of events that include all the activities of the cell

mitosis - nuclear replication of eukaryotic cells

cytokinesis - the division of the cell and cytoplasm into halves, each half containing a nucleus

interphase - the remainder of the cell cycle other than mitosis, including cytokinesis (C ), gap 1 (G₁), synthesis (S), and Gap 2 (G₂).

chromatids - each chromosome consists of an identical pair of these chromosomal DNA strands

centromere - point at which the two sister chromatids are attached

prophase - mitotic spindle begins to form. Polar kinetochore fibers comprise the mitotic spindle.

metaphase - the chromosomes align on a plane in the center of the cell

anaphase - the sister chromatids separate.

telophase - mitotic apparatus disassembles.

centrioles - microtubule organizing centers (found only in eukaryotes…)

polar fibers - protinaceous microtubules that form between the centrioles

mitotic spindle - (spindle apparatus) the bridge of microtubules formed between the centrioles

kinetochore fibers - polar fibers that extend to each chromosome’s kinetochore

kinetochore - are where the kinetochore fibers (microtubules) reach and hook up

aster - arrangement of microtubules radiating from a centriole

cleavage furrow - crevasse in the cell where cytokinesis takes place

meristems - localized areas of rapid cell division (found on the outmost end of onion root tips)

cell plate - partition setup perpendicular to the axis of the spindle apparatus in a plant cell

diploid - refers to a nucleus with two of each type of chromosome.

Key points:

know the stages of mitosis and the placement of mitosis in the cell cycle:

gap 1

synthesis

gap 2

MITOSIS:

prophase

metaphase

anaphase

telophase

(Note: This is all according to the BIO LAB book, NOT PIRTLE…)

Be able to identify stages of mitosis when viewing a slide through a microscope.

know the movement of "stuff" during mitosis (what goes where… ex: where do the chromosomes go during metaphase…)

know what the spindle looks like in 3-D

what color does Schiff’s reagent turn after the reaction of staining an onion root tip? (clear to bright red)

what color were the roots tips actually? (purple)

Nice QUIZ questions:

Vocab 2 luv:

meiosis - process of nuclear division that reduces the number of chromosomes by half (a.k.a. "reductive division")

diploid - occurring in double sets (pairs) in each nucleus

homologous chromosomes - the two chromosomes of a pair

loci - sites on a chromosome that represent a gene

haploid - single set of chromosomes (meiosis reduces diploid cells to this)

synapsis - the pairing of homologous chromosomes

alleles - various segments of the genetic material that are "crossed over" during synapsis

crossing-over - the exchange of this genetic material

gametes - reproductive cells with haploid nuclei resulting from meiosis

gametogenesis - the formation of gametes

spermatogenesis - the formation of sperm cells

oogenesis - the formation of egg cells

seminiferous tubules - tightly coiled tubes where spermatogenesis occurs, in the male testes

spermatogonia - diploid cells that constantly reproduce that are packed tightly against the inner walls of the tubules

primary spermatocytes - daughter cells that move inward toward the lumen of the tubule and begin mitosis

secondary spermatocytes - products of the primary spermatocytes after going through meiosis I (TWO are produced)

spermatids - products of the secondary spermatocytes after going through meiosis II (Four total now)

sperm - spermatids that mature and differentiate along the length of the seminiferous tubule

oocytes - cells of the ovary that produce female gametes

primary oocytes - the oocytes found in the ovaries of females (NOTE: these are one and the same - primary oocytes are never produced - the female fetus carries them all from conception)

follicular cells - these cells surround the primary oocytes at birth, when they have begun meiosis I, but stopped in prophase I

follicles - the whole thing (primary oocytes surrounded by folicular cells)

(oocyte enlarges as the number of folicular cells around the oocyte increases)

(at puberty, hormones begin to stimulate growth of one or two of these dormant follicles and their primary oocytes each month)

ovulation - release of the oocyte from the ovary

secondary oocyte - product of the entire meiosis II process

polar body - product of meiosis II - small mass left over from huge cell division

Graafian follicle - a mature follicle that contains a secondary oocyte

fertilization - fusion of the two sex nuclei

corpus leteum - what the remaining follicle cells form that produces hormones that prepare the uterus for the potential arrival of a fertilized egg

Key stuff to note and glance at:

(REMEMBER THIS ONE?: It’s the lab from hell that took FOREVER! We got a handout on this, so read it…)

Chemicals to taste:

TE (Tris/Ethylene diamine tetraacetic acid pH 8.0) - buffer

SDS (sodiuim dodecyl sulfate) - detergent that denatures proteins

NaCl - salt used to neutralize DNA

CTAB (methylated ammonium bromide) - precipitates polysaccharides

chloroform - solubilizes lipids (a.k.a. KNOCK OUT GAS)

isoamyl alcohol - deproteinizes DNA

isopropanol - precipitates (dehydrates) DNA

ethanol - wash that removes the salt (NaCl) from the DNA

RNAse - enzyme that degrades RNA

lysozyme - an enzyme that breaks down the cell wall

-------- PART TWO ---------

Endonuclease - DNA binding protein (enzyme) that cuts specific regions of the DNA strand

TBE (Tris / Boric Acid / EDTA) - running buffer (1X)

Agarose - a product of seaweed. Provides matrix for separating DNA according to size

Ethidium Bromide (ETBr) - reacts with ultraviolet light to produce an orange glow. Intercalates between base pairs (CARCINOGENIC!!!! Use gloves!!!)

loading dye - has GLYCEROL which causes DNA to sink. Also allows you to track migration of DNA

UV illumination - use glasses - you can burn your EYEZ out… J

stuff you MIGHT just wanna know:

Vocab you hate:

Mendelian genetics - the conclusions that led to the basis of genetics by Gregor Mendel

particulate theory - the blending theory of inheritance that Mendel replaces (mixing paint)

Law of Segregation (1^st law) - Each gamete has an equal chance of possessing either member of a pair of homologous chromosomes

Law of Independent Assortment (2^nd law) - genes on nonhomologous (different) chromosomes will be distributed randomly into gametes

gene - the basic unit of heredity on a chromosome

alleles - alternate states on a gene

dominant - over recessive

recessive - under dominant

genotype - the gene expression

phenotype - the physical appearance of the trait

homozygous - same alleles (tt or TT)

heterozygous - different alleles (Tt)

first filial - f₁ generation = first generation of offspring

codominance - genes that are both expressed

antigens - proteins on the surface of red blood cells that determine blood type (ANTIGENS ARE THE TYPE!!!)

antibodies - proteins that agglutinate other foreign blood cells

widow’s peak - pointed hairline

galactosemia - inability to metabolize galactose, MILK SUGAR

------ PART TWO ------

evolution - theory that broadly describes genetic change in populations

mutations - changes in the genetic message of a cell

fitness - tendency to produce more offspring than competing individuals produce

natural selection - U SHOULD KNOW THIS ALREADY!!!

frequency - the proportion of individuals in a certain category relative to the total number of individuals considered

Hardy-Weinberg Principle (equilibrium) - p + q = 1 p²+ 2pq +q²= 1

selection - the differential reproduction of genotypes

selection pressures - factors that affect organisms and result in selective reproduction of genotypes (i.e. temperature)

The Volvocine Line:

Chlamydomonas - unicellular green algae: most primitive & widespread. Isogamous (all gametes identical in size and appearance)

Gonium - simplest colonial member of the Volvocine line. 4, 8, 16, or 32 Chlamydomonas-like cells held together by a gelatinous matrix. Isogamous

Panadorina - 16 or 32 chlamydomonas cells held in gelatinous matrix. Moves via flagella. When at biggest size, they divide to form two new colonies.

Eudorina - spherical colony --? 32, 64, 128 cells. Differ in size. Cannot reproduce to form new colonies.

Volvox - largest in line. Thousands of vegetative cells. End of the Volvocine Line.

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