Chromosomes- vehicles for transmitting genetic information

Mitosis- somatic cells

Meiosis- production of sex cells (gametes)

1940- year when transmission electron microscope was developed

Electron microscope- allowed cells to be seen in highly organized structures (form and function)

Mitochondria and chloroplasts- contain their own unique genetic information

Plasma membrane- outer covering that defines cell boundaries and delimits cell from external environment

Cellulose- polysaccharide, what the cell wall is made of

Glycocalyx- cell coat, provides biochemical identity, cell-identity markers

Receptor molecules- recognition sites, transfer chemical signals across the cell membrane into the cell

Animal Cells- plasma membrane, glycocalyx

Plants cells- cell wall

Chromosomes- what chromatin fibers condense into

rRNA- ribosomal assembly

NOR (nucleolus organizer region)- portions of DNA that encode rRNA

ER (endoplasmic reticulum)- compartmentalizes the cytoplasm, increasing the surface area for biochemical synthesis

Ribosome- serve as site where genetic information contained in mRNA is translated into proteins

Mitochondria- oxidative phases of cell respiration, generate ATP

Chloroplasts- photosynthesis

Centrioles- located in centrosome, organizes spindle fibers

Tubulin- protein polymers, what microtubules are made of

Centrosomes- responsible for organizing microtubules into the spindle fibers

Cohesin- multi-subunit protein complex holding sister chromatids together, formed during s phase

Metaphase plate/ equatorial plane- midline region of the cell

Kinetochore- plates of proteins where spindle fibers bind

Shugoshin- protein family “guardian spirit” protects cohesin from being degraded

Separase- enzymes that degrades cohesin

Middle Lamella- cell plate laid down during telophase

Why “p” arm and “q” arm? P for petite and Q because it is the next letter

Karyotyping- chromosomes are photographed, cut out, printed, and matched up

Locus/Loci- identical gene sites

Zygotes- single-celled fertilized egg

Mitotic activity- basis for wound healing and cell replacement

Reticulocytes- shed their nuclei and replenish the supply of red blood cells in vertebrates

Karyokinesis- nuclear division

Cytokinesis- cytoplasmic division

Interphase- the initial stage of the cell cycle, replication of DNA

Cell Cycle Sequence= G1, S, G2, M

G1, G2, S phase= intensive metabolic activity, cell growth, and cell differentiation

By the end of G2, the volume of the cell has doubled

Vitro- “in glass”

Time Interval of Cell Cycle

1. G1- 5 hrs

2. S- 7 hrs

3. G2- 3 hrs

4. M- 1 hr

   1. Prophase- 36 mins

   2. Metaphase- 3 mins

   3. Anaphase- 3 mins

   4. Tel- 18 minutes

Prophase- cell phase migrating 2 pairs of centrioles

Prometaphase & Metaphase- migration of every chromosome

Prometaphase- chromosome movement

Metaphase- chromosome configuration

Anaphase- chromosome distribution, shortest stage of mitosis

Telophase- 2 complete sets of chromosomes are present, one set at each pole

For complete disjunction to occur:

1. Shugoshin must be degraded

2. The cohesin is cleaved by separase

3. Sister chromatids are pulled towards opposite poles

Difference between plant and animal cell cytokinesis? Plants just have a metaphase plate down the middle, animal cells undergoes constriction

CDC mutations- mutation that exert an effect at one or another stage of the cell cycle

Kinases- enzyme products of many of the mutated genes, can add phosphates to other proteins

Cyclins- molecules that control conjunction with proteins, bind to kinases

Cyclin-dependent kinases- phosphorylate target proteins that regulate the progress of the cycle

Why must meiosis be very specific? Haploid gametes must contain precisely one member of each homologous pair of chromosome for genetic continuity

Crossing over- meiotic event resulting in genetic exchange between members of each homologous pair thus genetic variation

Prophase 1

Synapsis- pairing up of homologous chromosomes

Bivalent- synapsed pair of homologs

Tetrad- 2 pairs of sister chromatids

Dyad- half of a tetrad

Chiasma- chromatids are intertwined, crossing over

Terminalization- chiasmata shift towards the chromosome ends

1. Leptotene- homology search

2. Zygotene- synapsis, pairing up

3. Pachytene- recombination

4. Diplotene- chiasmata formation

5. Diakinesis- separation

Metaphase 1- chromosomes are shortened and thickened

Spermatogenesis- productions of male gamete,

Oogenesis- production of a female gamete

Spermatogonium- diploid germ cell

Spermatocyte- male gametocyte, sperm

Ova- female gametocyte, egg cell

Equal amount of genetic material but unequal amount of cytoplasm because it is needed to nourish the developing embryo

Diploid sporo[hyte stage and haploid gametophyte stage- life cycle of multicellular plants

Why is Meiosis important?

1. Serves as a bridge between the sporophyte stage (mitosis) and gametophyte stage (reproduction) of the life cycle

2. Mechanism that reduces diploid amount of genetic information into haploid which is needed for the sexual reproduction of all diploid organisms

Ernest DuPraw- folded-fiber model