Multicellularity Flashcards
Module 2
Main components of a bacterial cell are:
- no membrane-bound nucleus
- no mitochondria or chloroplasts (energy-producing organelles)
- small size
What are the three prokaryotic shapes
streptococcus, e. coli and streptomyces
What kind of bacteria aggregate to form multicellular reproductive structures made of several cell types
myxobacteria
How do bacteria reproduce?
Conjugation
- synthesize strand of membrane bound cytoplasm (PILI)
- once cells align, the plasmid (DNA) passes through the pili
Transformation
- dead cell DNA released into environment is taken by recipient cell
Transduction
- viruses with infected bacterial cells can INTEGRATE THEIR DNA into a host bacterial cell
This bacteria flourishes in extreme environments but can also live in soil, lakes and oceans
Archaeon bacteria
T/F the majority of bacteria is harmful
False
T/F 21% of the GI tract is bacteria
True
This cell type has a nucleus, dynamic cytoskeleton and membrane system
Eukaryotic cells
What are the 5 unique features of eukaryotic cells?
1.) energy metabolism is confined to organelles (requires membrane stability)
2.) nuclear membrane separates translation and transcription
3.) vesicles from membranes transport materials into the by endocytosis and release material by exocytosis
4.) cytoskeleton allows cell to change shape by quick remodeling
5.) network of membranes can change shape, package molecules and particles for transport within the cell.
T/F A amoebas is a eukaryote
True
T/F eukaryotic cells don’t engulf molecules or particles during endocytosis
false (they DO, phagocytosis is the specific endocytosis that eukaryotic cells surround food particles)
During sexual reproduction, between interphase and meiosis 1, what is created?
homologous chromosomes
Describe the cell process in sexual reproduction
two sets of chromosomes
interphase where the chromosomes from both gametes combine/mix and create homologous chromosomes
meiosis 1 occurs where daughter nuclei are created
meiosis 2 is the final step where daughter nuclei 2 are created
What are the 2 ways sex promotes genetic variation
meiotic cell division in gametes that are genetically unique
fertilization causes new combinations of genes brought together through the fusion of gametes
What is the eukaryotic cell life in animals
zygote divides many times to form multicellular diploid bodies
small subset of cells will undergo meiotic cell division to form haploid gametes (egg/sperm)
what is the eukaryotic cell life cycle in plants
a zygote grows with mitosis to create a reproductive cell
meiosis occurs, causing some spores and some to go onto grow with mitosis
mitosis makes those cells become gametes and fusion then occcurs
Zebras Make Reigns, Most Make Muffins, Grandma’s Favourite
These properties are all properties of what?
1.) adhesion molecules makes adjacent cells stick together with little/no communication
2.) little differentiation of specialized cell types
3.) most cells will retain full range of functions
4.) every cell is in contact with the external environment
Simple Multicellularity
The properties of complex multicellularity are?
1.) only evolved 6 times
2.) specialized structures from cell communication
3.) tissue/organ differentiation
4.) 3D organization (only some cells are in contact with external environment)
5.) require mechanisms to transfer environmental signals to cells for reposne
Multicellularity evolved in which eukaryotic groups?
1.) animals
2.) green algae
3.) red algae
4.) brown algae
5.) fungi
6.) fungi (2 groups of fungi)
This method of transport is defined as the molecules net movement from high concentration to low concentration
Diffusion
Bulk transport is different from diffusion due to?
it requires molecules to move at rates not possible with diffusion
ex.) pumping oxygenated blood
Adhesion is
cells dividing rapidly but staying stuck together
Cadherins, integrins and other transmembrane proteins are examples of what
animal adhesion cells
How do cells communicate?
all cells have transmembrane receptors that respond to signals from the environment
signaling molecules bind to receptor molecules which grants or inhibits an action
gap junctions are also used
Difference between plants and animals complex multicellularity
plants:
- cell wall is made of cellulose
- no endocytosis
- growth confined to meristem
- site-specific cell division
- site-specific differentiation
animals:
- fertilized egg = blastula (ball of undifferentiated cells)
- signal gradient defines top/bottom/sides of cell
- not constrained; can form organs and moving parts
