Micro Exam #2

Microbes that normally live on the skin, in the gastrointestinal tract, and in other sites are called the normal resident __________.

microbiota

Of the microscope fungi,___ are filament thread-like cells called hyphae while____ are round or oval shaped.

molds;yeasts

Simple diffusion is defined as the movement of

molecules from areas of higher concentration to areas of lower concentration

Together, the capsid and the nucleic acid are referred to as the __________.

nucleocapsid

If the DNA of the provirus is transcribed

one long polygenic mRNA is produced.

Barophiles

optimal growth at high pressure

Acidophiles

optimal growth at low pH

Psychrophiles

optimal growth below 15°C

Thermophiles

optimal growth from 45°C—80°C

Capnophiles

optimal growth in 3—10% CO2

Halophiles

optimal growth in high salt concentrations

Osmophiles

optimal growth in high solute concentrations

A prophage is

phage DNA integrated into host cell genome.

In the lytic cycle of phage replication

phage nucleic acid is replicated and phage genes are expressed, making new phage protein and lysing the host cell.

The cell wall of a bacterial cell

prevents lysis of the cell in hypotonic conditions.

Which of the following represents the correct order of the phases of mitosis?

prophase->metaphase->anaphase->telophase

Eukaryotic ribosomes are the site of

protein synthesis

Eukaryotes that are not plants, animals, or fungi make up a diverse category of organisms classified as______.

protists

while examining a sample of pond water you note a cell covered with thousands of minute hair-like extensions which it uses to propel itself through the water. this cell can immediately be classified as a/an

protozoan

A red blood cell placed in a hypertonic medium will

shrink

in electron micrographs, portions of the endoplasmic reticulum (ER) appear rough on the edges. This is because

some regions of the ER are covered with ribosomes

The general term used to denote a situation in which two organisms live together in a close partnership required by one or both members is __________.

symbiosis

The two major groups of parasitic flatworms include the ____ with a long, ribbon-like body and the ____ with a flat, ovoid body.

tapeworms; flukes

The rate of diffusion is affected by which of the following?

temperature, size of molecules, steepness of the concentration gradient

When sugar is mixed with water, equilibrium is reached when

the dissolved sugar molecules are evenly distributed throughout the solution.

Which of the following statements about microtubules during anaphase is TRUE?

those attached to chromosomes shorten, while those that are unattached elongate

Retrovirus have

two copies of single-stranded RNA

Which of the following is NOT a characteristic of active transport?

use of proteins to move molecules with the concentration gradient

The first event to occur is

viral spike proteins are inserted into host cell membrane.

Choose the answer that fills in the blanks of this sentence in correct order. The cell____ support while the cell____ is found in all eukaryotic cells, is composed of phospholipids components from the external environment.

wall; membrane

Osmosis is best defined as the movement of

water molecules across a membrane from an area of high water concentration to an area of lower concentration

Please select criteria that are used to classify viruses.

-Capsid structure -presence/absence of an envelope

Select all of the statements that are true regarding penetration of animal viruses.

-Enveloped viruses can penetrate by fusion. -Enveloped viruses can penetrate by endocytosis. -Nonenveloped viruses can penetrate by endocytosis. -Once inside the host, viruses become uncoated.

Please match the stages of the population growth curve with the statements that most accurately describe them.

-Lag Phase: cells require a period of adjustment after being newly inoculated -Exponential Growth Phase: population reaches maximum growth rate -Stationary Growth Phase: rate of cell inhibition and cell death balances the rate of multiplication, and population size remains constant -Death Phase: population declines as death of cells exceeds rate of multiplication

Please select characteristics exhibited by protozoa to test your understanding of protozoan form, nutrition, and locomotion.

-Protozoa can move using flagella, pseudopodia, or cilia. -Protozoa have an ectoplasm involved in locomotion, feeding, and protection. -Protozoa can be free-living or parasitic

Please select all of the following that represent viral characteristics.

-are obligate intracellular parasites -have a 20 to 450 nanometer diameter -are composed of a capsid surrounding a nucleic acid core

Please select all of the following which are eukaryotic locomotor appendages.

-flagella -cilia

Please select all of the following that are true regarding fungi.

-fungi can be found in two cell forms:hyphae & yeasts -most fungi obtain nutrients from decaying matter but some fungi can be parasites of living -fungi are heterotrophic

Please select the characteristics which have traditionally been used to place plants, animals, and fungi into separate kingdoms

-general cell type or body plan -acquisition of nutrients and nutritional requirements -cell shape

Organelles which contain DNA include the

-mitochondria -chloroplast

Please select the cellular structures that are present in ALL eukaryotic cells.

-mitochondria -nucleus -cytoskeleton

All viruses

-possess a capsid composed of protein. -are reliant on a host cell for their own reproduction.

Which of the following elements are NOT one of the six elements found in lipids, nucleic acids, and proteins?

-potassium -calcium -iron

Fungi may obtain nutrition from

-the remains of dead plants or animals -a living host

Which of the following strategies are used by parasitic helminths to ensure their survival

-use of mouth glands to breach host tissues -fertilized eggs are provided with a protective shell -some worms carry millions of eggs in development

The correct order of the stages for phage replication are 1 = Assembly2 = Attachment3 = Transcription/replication4 = Release5 = Penetration

2, 5, 3, 1, 4

The eukaryotic ribosome is a___ ribosome , composed of 40S and 60S

80S

Which of the following is not typically found inside a chloroplast?

80S ribosomes

Obligate __________ live at low pH extremes and sometimes maintain the low pH by releasing strong acid.

Acidophiles

Methanogens are a type of archaea found in various habitats on the planet, including deep-sea vents in the deepest parts of the ocean. They produce methane gas by reducing carbon dioxide, using hydrogen gas under anaerobic conditions. Given these characteristics, methanogens are a type of __________.

Chemoautotroph

A true aerobe lacks the metabolic enzyme systems for using oxygen gas in respiration.

False

DNA replication occurs in mitosis

False

Once a phage becomes lysogenic, it will remain lysogenic and never be lytic again.

False

Purple and green sulfur bacteria get their energy from oxygenic photosynthesis.

False

The light microscope was critical in the discovery of viruses.

False

The use of antibiotics is an effective treatment for viral infections. Group starts

False

Viral nucleic acid is made inside the bacterium and is combined with viral protein coat already present outside.

False

Viral replication follows essentially the same steps as replication of a prokaryotic cell.

False

Viruses are routinely cultured in order to diagnose an infection.

False

Viruses first appeared on Earth sometime after the rise of eukaryotic organisms.

False

Which of the following represents the correct order of the phases of the cell cycle?

G1->S->G2->M

The term biologists use to describe all of the adaptations organisms make to their environment is __________.

Niche

Which of the following is incorrect about protozoan pathogens?

Protozoa cannot be spread through body fluids.

__________ metabolize organic matter from dead organisms while __________ require a live host.

Saprobes; symbiotic microbes

A phage-induced lysozyme lyses the host cell releasing the newly made phage.

True

Diffusion is one of the processes whereby materials are exchanged between a cell and its environment.

True

If a cell is placed in an isotonic medium, there will be no net movement of water.

True

If the virus is present as a provirus in the host cell, it remains latent and never produces new virus.

True

One aspect of microbial growth includes the synthesis of new cell components and size increase of an individual cell.

True

The ease of global travel and increased immigration has affected the worldwide distribution of helminth infections

True

The hepadnavirus family is so named because viruses within the family infect the liver and possess DNA as their genetic material.

True

The majority of heterotrophic microorganisms are chemoheterotrophs that derive both energy and carbon from organic compounds

True

The viral-host relationship is extremely important for pathogenicity, mode of transmission, the immune response, and the human measures used to control viral infections.

True

Viral nucleic acid enters the host cell and uses host cell's replication and synthesis machinery in order to produce new nucleic acid molecules, proteins for the capsid, spikes, and viral enzymes.

True

Which of the following does NOT represent an event in bacteriophage multiplication?

Uncoating of the nucleic acid in cytoplasm

Which step is present in bacteriophage multiplication but not in multiplication of an animal virus?

Viral genetic material is injected into the host cell.

Amoeba have no cell walls and when water enters the cell via osmosis, the amoeba must expend energy to expel the water. Bacteria do not do this because

bacteria have cell walls

The viral capsid

becomes completely enclosed by the region of the cell membrane into which the spikes and matrix protein are embedded

Enveloped viruses are usually released from the host cell by

budding

Which of the following events do NOT occur in prophase of mitosis?

chromosomes are replicated

The division of the cytoplasm is called

cytokinesis

When a trophozoite is exposed to dry conditions or a lack of nutrients, it will enter the _______ phase. Cells in this phase round of and lost motility and are called _______. When the environment becomes moist and nutrients are restored, the protozoan will enter _______, thus reactivating the trophozoite.

encystment; cysts; excystment

The algae are photosynthetic, eukaryotic protists that are grouped into ______ (no cell wall and motile by flagella) , ______ (single-celled with golden chloroplasts and intricate cell walls), ______ (cause "red tide"), kelp, red seaweeds and green algae

euglenids; diatoms; dinoflagellates

The two major groups of parasitic helminths include the ____ with a thin, segmented body and the ____ with a cylindrical, unsegmented body.

flatworms; roundworms

Organisms that require a high concentration of salt are called __________.

halophiles

Please choose the answer that describes the function of the Golgi complex.

it adds lipids and sugars to proteins and then packages these proteins for transport to their final

Which of the following terms is associated with the release of nonenveloped or complex viruses from the host cell?

lysis

Hypotonic

The environment inside the cell has a lower solute concentration than the environment outside the cell

isotonic

The environment inside the cell has the same solute concentration as the environment outside of the cell.

Please choose the statement that describes the primary medical threat due to algae.

Marine algae produce toxins which accumulate in seafood and can cause severe food poisoning.

Hypertonic

The environment inside the cell has a higher solute concentration than the environment outside the cell.