Lab Exam 2 Pt.1
How is Cladophora morphologically similar to Spirogyra? How is it different?
-Both branched -Cladophora is coarser
Plasmodial slime molds
-DO NO CONFUSE WITH THE SPOROZOAN PLASMODIUM -live beneath detached bark on decomposing tree trunks and resemble a moving mass of slime.
What are conceptacles?
-The tips of the fucus that branches -may be swollen and contain structures called oogonia(female) and antheridia(male)
What are Sporozoans?
-are nonmotile, spore forming parasites of animals. -Their "spores" are small, rather featureless stages in their life history that are transmitted from host to host.
Where do Spirogyra grow?
-in running streams of cool freshwater -they secrete mucilage that makes it feel slippery
Where are Cladophora found?
-in streams -much coarser appearance and texture
What are Plasmodium?
-sporozoan that causes malaria. -infect and rupture red blood cells, causing cycles of fever and chills
What are the main events that take place in Prophase?
1. Chromosome compaction into condensed chromosomes 2.The mitotic spindle forms 3.The nuclear envelope begins to disassemble
What are the main events in metaphase?
1. Chromosomes are fully condensed 2.Chromosomes line up along the metaphase plate 3.Cohesin proteins dissociate
What are the main events in Telophase?
1. Chromosomes arrive at poles and decondense. 2. The nuclear envelope reforms 3.The mitotic spindle disappears.
What does Mendel's particulate theory state?
1. inherited characteristics are determined by particular factors. 2.these factors occur in pairs 3.when gametes form, these genes segregate so that only one of the homologous pair is contained in a particular gamete.
What are the main events in Anaphase?
1.Sister Chromatids are separated. 2. Chromosomes are pulled to opposite poles of the cell
How many chromosomes does a cell have after it completes mitosis?
16
Suppose synapsis occurred between two homologous chromosomes and one had alleles for blue eyes and brown hair where the other had alleles for green eyes and blonde hair. How many different combinations of these alleles would be possible?
16
Synapsis occurs after chromosomal DNA has replicated. How many chromatids are involved in crossing-over of a homologous pair of chromosomes?
4
If a nucleus has eight chromosomes during interphase, how many chromosomes does it have during metaphase?
8
What is a cell plate, and in what stage of mitosis does it form?
A cell plate occurs in cytokinesis. It forms in telophase.
What is Paramecium?
A free-living freshwater ciliate.
When the sister chromatids begin to separate?
Anaphase
What domain do archaebacteria belong to?
Archea
Interphase has sometimes been called a "resting stage." Why is this inaccurate?
Because DNA is being replicated and condensed
Why do some scientists call conjugation sexual reproduction and other do not?
Because genetic recombination occurred but no increase in cell numbers
Is the cell the fundamental unit of life in plasmodial slime molds? Or is the whole organism, regardless of composition, the fundamental unit?
Because in general the cell is considered the fundamental unit of life, this is no different for slime molds
Why would we choose an embryonic mass of cells to study the stages of mitosis?
Because it allows us to see each stage and see them split into new cells
Why is the division of Paramecium cells called transverse fission?
Because it consists of the spontaneous transverse segmentation of the body
Why would shuffling of genetic material to produce new combinations of characteristics be advantageous to a species?
Because it creates diversity
Why is transverse fission not a sexual process?
Because it occurs within itself which make it asexual
Why are unicellular organisms that reproduce by mitosis considered immortal?
Because they just keep dividing and dividing, producing clones, so there is no genetic diversity
Brown algae contain chlorophyll, so why do hey appear brown and not green?
Cartenoid pigment makes them appear brown. The brown pigment overwhelms the green of chlorophyll a.
What is happening in interphase of a cell?
Dna replicates and begins to condense. histones are synthesized
Why is pinching of the cytoplasm inadequate for cytokinesis in plant cells?
Each plant cell needs its own cell wall to surround it. So if the cell just pinches off, there will be two cells in one wall.
What alga does a trypanosome superficially resemble?
Euglena
What is Phylum Chlorophyta?
Green Algae
What is the most diverse and familiar algae in freshwater?
Green algae
What is the function of the eyespot of Euglena?
Helps the Euglena move towards light. (Sensory)
Why is it important that decomposers such as bacteria release nutrients?
If nutrients weren't released, eventually it would all be locked up in dead, non-decaying tissue.
When would shuffling genetic material to produce new combinations be bad?
If there is a desirable trait that you do not want to be altered.
How does cytokinesis differ in plant versus animal cells?
In plant cells vesicles first line up to form a new cell wall whereas in animal cells the cell membrane pinches and divides
What is the cleavage furrow?
It forms in cytokinesis and begins on the periphery of the cell and pinches inward, and eventually divides the cell into two cells
What happens when milk is pasteurized?
It kills the bacteria by heating up the milk
What causes milk to sour?
Lactose reacts with oxygen to make lactic acid, which is sour
What phase in mitosis do the chromosomes align on a plane in the center of the cell?
Metaphase
What two type of nuclei do ciliates have?
Micronuclei and Macronuclei
What are the major differences between the events of meiosis and mitosis?
Mitosis=2 identical cells Meiosis=4 haploid cells
What conclusion about your genotype is evident if one of your siblings, but neither parent, shows the recessive trait?
One of the parents carries the recessive trait, but doesn't show it in their phenotype. (Tt
How do algae affect your life?
Oxygen production, food source, medicine
Describe aspects of their a parameciums movement compared to amoeba.
Paramecium= use cilia to strain Amoeba=pull themselves along by partially extending
What phylum does brown algae belong to?
Phylum Phaeophyta
What phylum does red algae belong to?
Phylum Rhodophyta
In what sense are protists primitive and in what sense are they considered advanced?
Primitive=simple organization Advanced=contain protoplasmic organelles like cilia and flagella
What phase do the miotic spindle fibers begin to form?
Prophase
What kingdom of eukaryotes is the oldest and most diverse?
Protista
How could bacteria become resistant to an antibiotic?
Some change the structure of their cell envelope so that it lets in smaller units of biocides. Others pump out the toxic compounds.
What is the shape of the chloroplasts of Spirogyra?
Spiral
Spirillum
Spiral shaped bacteria
What are the two most common genera of filamentous green algae?
Spirogyra and Cladophora
When does the cleavage furrow appear?
Telophase
When does the mitotic apparatus disassemble?
Telophase
If a nucleus has eight chromosomes when it begins meiosis, how many chromosomes does it have after telophase I? Telophase II?
Telophase I= 4 Telophase II=4
Bacteria are heterotrophic, what does this mean?
That they derive their energy from organic molecules made by other organisms.
How large is a trypanosome relative to Amoeba?
The trypanosome is 50x smaller than the amoeba
Define diatomaceous earth
The walls of diatoms accumulate in layers of diatomaceous earth several hundred meters deep. This depth indicated how many diatoms have existed through the ages.
What functions do cilia, flagella, and pseudopods have in common?
They all help in locomotion
What ecological roles are performed by cyanobacteria?
They are producers
How do antibiotics kill bacteria? Why do they not affect viruses?
They attack the outer cellular or inner membrane; Viruses don't reproduce in an independent manner.
What requirements might make culturing parasitic zoomastigotes difficult in the lab?
They need hosts in order to survive. We can't culture them in artificial media.
T/F Mature Cladophora exist in diplod and haploid forms
True
Are cilia visible on living or prepared Paramecium?
Yes
Are the filaments of Spirogyra branched?
Yes
Are the stem, holdfast, and blade of brown algae the same as stems, roots, and leaves of land plants?
Yes
Does Paramecium rotate as it moves?
Yes
Is cytoplasmic movement of Physarum apparent?
Yes
Would evolution occur without the events of meiosis and sexual reproduction? Why or why not?
Yes. But not to the extent we see today. Mutations can occur in asexual reproductions which would result in altered genes. But sexual reproduction is the best way for evolution and diversity.
What is fission?
a cell's DNA replicates and the cell pinches in half without the nuclear and chromosomal associated with mitosis
What is fucus?
a common genus of brown algae
What is meant by the term kelp?
a large brown seaweed
In plant cells cytokinesis includes a formation of what???
a partition, called a cell plate
What are the advantages and disadvantages of conjugation in Paramecium?
advantage=stimulates metabolism and is followed by frequent mitosis disadvantage=requires two organisms and requires more energy.
What kind of organisms do Protists include?
all eukaryotes that lack distinguishable characteristics of fungi , animals, or plants.
What is conjugation?
all or part of the genetic material of one bacterium is transferred to another bacterium and a new set of genes is assembled
What are alleles?
alternate states of a gene
When are homologous chromosomes separated in meiosis?
at the end of meiosis I
When are the chromatids composing each chromosome separated?
at the end of meiosis II
What is a possible function of cytoplasmic movement in physarum?
avoiding light; finding food
What is Gram Negative?
bacteria that have a much thinner cell wall that does not retain the dye
What is Gram Positive?
bacteria that have a thick cell wall that retain purple dye.
What is an example of an unicellular algae?
chlymydomonas
How do spirogyra reproduce?
conjugation
Where do brown algae grow?
cool water
What are Protozoans?
eukaryotes with an animal like heterotrophic lifestyle, which means they are consumers
How do Bacteria reproduce?
fission
What is the pigment that is present in brown algae?
fucoxanthin
The haploid stage of the in Cladophora life cycle produces gametes and is called the_______?
gametophyte
Define Alternation of Generations
is a reproductive cycle in which the haploid gametophyte produces gametes that fuse to form a zygote that germinates to produce a diploid sporophyte
What is Mitosis?
it is the replication and division of the nucleus of a eukaryotic cell in preparation for cytokinesis.
Where can you find fucus?
it typically is attached to rocks in the intertidal zone via a specialized structure called a holdfast
Can you see any pores in the walls of diatoms?
no.
Colonial algae
occur as groups of cells attached to each other in a nonfilamentous manner
What are chlorophylls and carotenoids?
other algal pigments that are insoluble in water but can be extracted with organic solvents such as acetone and alcool
What term best describes heterotrophic bacteria that feed on living tissue?
parasitism
What are Trypanosomes?
pathogenic protozoan and cause African sleeping sickness and Chagas' disease
Where is the cell plate located?
perpendicular to the axis of the spindle apparatus , but forms in the middle of the cell
What are algae?
photosynthetic, eukaryotic organisms typically lacking multicellular sex organs
Bacillus
rod-shaped bacteria
Coccus
spherical shaped bacteria
What is an example of a filamentous algae?
spirogyra
The diploid stage of the life cycle in Cladophora produces spores and is called the________?
sporophyte
Which stage of mitosis most often is associated with the beginning of cytokinesis?
telophase
What does the Law of Segregation state?
that each gamete has an equal chance of possessing either member of a pair of homologous chromosomes
What does the Law of Independent Assortment state?
that genes on nonhomologous or different chromosomes will be distributed randomly into gametes
What is one of the techniques used to classify bacteria?
the Gram Stain
What is cytokinesis?
the division of the cell and cytoplasm into halves that each contain a nucleus.
What is synapsis?
the pairing of homologous chromosomes
How does red algae get its color?
the presence of red phycobilins in their plastids
What region of a root has the most mitotic activity?
the tip
What is Euglena best known for?
their ability to be either autotrophic, heterotrophic, and saprophytic
Define Meristems
they are localized areas of rapid cell division due to active growth at the root tips.
Filamentous algal
they occur as chains of cells attached end to end
Unicellular algal
they occur as single, unattached cells that may or may not be motile
Where do Archaebacteria live?
they often inhabit but are not restricted to extreme and stressful environments
Is the movement in a particular direction?
towards the food
Porphyra are red algae that have "blades." What do these "blades consist of?
two layers of cells separated by colloidal material
What are Zoomastigotes?
unicellular, heterotrophic, and have at least one flagellum; most primitive protozoans
What is an example of a colonial algae?
volvox
Where do red algae live?
warm marine waters
What does autotrophic mean?
when an organism, in this case bacteria, derive their energy from photosynthesis or the oxidation of inorganic molecules
Can you see the conjugation tubes in Spirogyra?
yes
