Cocci
roughly spherical shaped prokaryotic cell
Bacilli
rod shaped prokaryote
What are the two types of spiral prokaryotes?
Spirillum (stiff) and spirochetes (flexible)
vibrios
slightly curved rods
coccobacillus
intermediate shape between cocci and rods
pleomorphic
prokaryotes that vary in size and shape
Binary fission
a form of asexual reproduction and cell division used by all prokaryotes
Snapping division
a mode of cell division characterized by rapid horizontal division
spores
reproductive cells produced by actinomycetes at the ends of their filamentous cells -- each spore can develop into a clone of the original organism
budding
a form of asexual reproduction in which an outgrowth of the parent cell receives a copy of the genetic material, enlarges and detaches.
what characteristics determine the arrangement of prokaryotic cells?
the plane in which cells divide and weather or not the daughter cells seperate completely or remain attached.
diplococci
cocci that remain in attached pairs
streptococci
long chains of cocci
tetrads
the result of cocci that divide in two planes and remain attached
sarcinae
the result of cocci that divide in three planes
staphylococci
clusters of cocci that form due to random planes of division
what happens to daughter bacilli when they seperate?
they can either become single cells or remain attached as pairs or as chains
what is a palisade?
a v shape or side by side arrangement of cornynebacterium diptheriae that remains attached.
Endospore
a dormant, tough and temporarily non reproductive structure produced by bacillus and clostridium bacteria.
what is meant by the term dormant as it pertains to endospores?
a resting stage that barely metabolizes and germinates only when environmental conditions improve.
Name 4 general characteristics of eukaryotic reproduction
1. Eukaryotic DNA is packaged with histone proteins as chromosomes.. 2. eukaryotes have a variety of methods of asexual reproduction. 3. many eukaryotes reproduce sexually.. 4. algae, fungi, and some protozoa reproduce both sexually and asexually.
how many complete copies of the chromosomal portion of a cells genome are contained in a eukaryotic nucleus?
either one or two
Diploid
the nucleus has two sets of chromosomes. Typically a zygote is diploid.
haploid
the nucleus has a single copy of each chromosome. Typically gametes are haploid.
What are the two main stages in the life cycle of a cell?
Interphase and mitosis.
Interphase:
the phase during the life cycle of a cell in which cells grow and eventually replicate their DNA
Mitosis
the phase during the life cycle of a cell during which the cells nucleus divides.
What are the four stages of mitosis?
Prophase, Metaphase, Anaphase, and Telophase.
Prophase:
chormatin condenses into cisible chromatids..... Sister chromatids are joined by centromeres
Metaphase
chromosomes line up on a plane in the middle of the cell
anaphase
sister chromatids seperate and move to opposite poles of the cell
telophase
the cell restores its chromosomes to their less compact, nonmitotic state.
Chromosome
consists of two chromatids during prophase and metaphase
during which phases do chromatids seperate?
anaphase and telophase.... then each chromatid is called a chromosome
Meosis
a special type of cell division that produces gametes with half as many chromosomes. It's like back to back mitosis without the replication of DNA between them.
What are the phases of meosis?
Early prohase 1, Late prophase 1 Metaphase 1, anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase2, and Telophase 2.
What does Meiosis produce from a single diploid nucleus?
Four haploid nuclei
What is Cytokinesis?
Cytoplasmic division which occurs simultaneously with the telophase of mitosis.
How does cytokinesis occur in plant and algae cells?
Cytokinesis occurs as vesicles deposit wall material at the equatorial plane in plant and algae cells.
Schizogony
form of division in which a series of nuclear divisions takes place before the segmentation of the cytoplasm.
Schizont
a multinucleate cell formed by multiple mitoses, which eventually bursts releasing daughter cells called merozoites.
Early prophase 1 (Meosis)
homologous chromosomes line up side by side.
Late prophase 1
exchange of DNA among homologous chromosomes (crossing over)
Metaphase 1
tetrads align on plane in middle of cell
Anaphase 1
chromosomes of tetrads move apart but sister chromatids remain attached.
Telophase 1
cell divides to form two cells
Prophase 2
nuclear envelope disintegrates
Metaphase 2
chromosomes align in the middle of the cell
Anaphase 2
sister chromatids seperate as in mitosis
telophase 2
Daughter nuclei form, cells divide yielding 4 haploid cells.