Lab Exam 2 Pt.1

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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


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