Questions Senior Comps Flashchards

Which of the following is true for exergonic reactions?

Products have less free energy than reactants.

In an enzyme-mediated reaction the word substrate(s) is another word for the:

The reactant on which an enzyme acts.

Which of the following is/are the location(s) of the Krebs cycle (citric acid cycle)?

Mitochondrial matrix.

Electromagnetic energy travels as _ but also acts as discrete packets of energy called _.

Travels as waves and occurs in discrete packets called photons.

The action spectrum of chlorophyll indicates:

Wavelengths of light utilized in photosynthesis.

Cellular respiration involves the ____ cycle while photosynthesis involves the _________ cycle.

Cellular respiration uses the Krebs cycle; photosynthesis uses the Calvin cycle.

Which of the germ layers gives rise to the skeleton and the circulatory system?

Mesoderm.

You have a hypothetical molecule ZX4. A small amount of this substance is placed in a large beaker of warm water and you observe that it dissolves completely. On the basis of this observation, you would be justified in concluding that ZX4 is a/an ______ compound.

May be an ionic or polar compound.

The rough endoplasmic reticulum is covered with:

Covered with ribosomes.

Characteristic of both facilitated diffusion and active transport is:

Both use membrane transport proteins.

Carrier protein molecules in the plasma (cell) membrane are required for:

Active transport and facilitated diffusion.

Hydrolysis is involved in which of the following?

Breaks triglycerides into glycerol and fatty acids.

Which of the following lists of elements includes the four most common elements found in living things?

Carbon, hydrogen, oxygen, and nitrogen (CHON).

A force of attraction between atoms:

Force of attraction between atoms.

Sister chromatids separate during _____________ _.

Occurs in mitosis and meiosis II.

_____ is NOT a formal stage of mitosis.

Interphase is not a formal stage of mitosis.

An epithelial tissue composed of several layers of flat cells would accurately be described as a _______ epithelium.

Epithelial tissue with several layers of flat cells.

Of the following types of muscle, which is/are attached to bones?

Skeletal muscle.

In plants, water transport is the function of _________, while sugar transport is the function of __________ _.

Xylem transports water; phloem transports sugars.

Which of the following is bigger in overall size?

All are approximately the same overall size during early cleavage.

A is the observable manner of expressing a certain trait.

Observable expression of a trait.

A nucleotide sequence started as GATTACA. After a point mutation, it reads CATTACA. What type of mutation occurred?

Point mutation by base substitution.

The liquid portion of blood is called ___.

Liquid portion of blood.

Hemolymph is the circulatory fluid found in _______ _.

Circulatory fluid found in arthropods.

In the human excretory system, countercurrent flow of fluids occurs in the ___.

Occurs in the loop of Henle.

Mendel crossed true breeding plants with distinct phenotypes. The F1 organisms were hybrids for the trait being studied. In this context, what kind of genotype does the hybrid organism possess?

Heterozygous.

A colorblind woman marries a man who is not colorblind. What percentage of their daughters will be colorblind?

0% colorblind daughters, assuming X-linked recessive inheritance; all daughters are carriers.

A gene's physical position along the length of a chromosome is its _______ _.

Physical position of a gene on a chromosome.

Typically, the regulatory genes in operons are _________ expressed.

Typically constitutive (continuous).

Based on the model of DNA, what piece of RNA would be synthesized if the upper DNA strand is used as a template. AATGCACGT # # # # # # # # # TTACGTGCA

UUACGUGCA.

When is the repressible Trp operon "off"?

When the tryptophan-bound repressor binds the operator.

Synaptic vesicles are filled with

Neurotransmitters.

Excessive production of aqueous humor can lead to elevated intraocular pressure and _________ _.

Can cause glaucoma.

The ________ is the standard contractile unit in skeletal muscle.

Standard contractile unit of skeletal muscle.

As nervous systems evolved in more complex organisms, a tendency to develop neural regulation centers in the head region occurred. This trend is called __________ _.

Evolutionary concentration of nervous-system regulation in the head.

The two senses with similar energy sources and overlapping functions are ________ _.

Touch and hearing; both detect mechanical stimuli.

In skeletal muscle contraction, ________ must be released from the sarcoplasmic reticulum before the active sites on actin filaments are exposed.

Calcium ions (Ca2+).

Protein digestion requires the enzymes _____ _.

Pepsin, trypsin, and peptidases.

Cellular level "memory" of which antibodies are needed to fight an invading antigen is an important feature in the _.

Feature of the humoral immune response.

Which of the following are invaginated respiratory devices? 1 - lungs 2 - tracheal tubes 3 - gills

Lungs and tracheal tubes.

A scientist must determine whether two populations of organisms are members of the same species. How should he/she apply the biological species concept?

Members of the same species can interbreed and produce fertile offspring.

According to the theory of common descent, which of the following is least accurate?

Humans did not descend from modern chimpanzees; they share a common ancestor.

According to Darwin, the principal mechanism of evolution is ___.

Natural selection.

What is the role of the individual in natural selection?

Survive and reproduce.

Only ___ traits can play a role in natural selection.

Heritable traits.

Arrange the following taxonomic ranks in the correct sequence from larger to smaller, according to the Linnaean hierarchic system of classification: 1 - family, 2 - genus, 3 - order, 4 - kingdom, 5 - phylum, 6 - class

Kingdom, phylum, class, order, family, genus.

A taxonomic group is one which contains a common ancestor and some (not all) of its descendants, compared with groups of the same rank.

Contains a common ancestor and some, but not all, of its descendants.

The term phylogeny refers to the ______ of a group of organisms.

Evolutionary history of a group of organisms.

A basic fungal organism consists of___.

Mycelium and spore-producing structures.

Evidence is emerging that animals and ___ form a monophyletic grouping within the eukaryotes.

Fungi.

In the carbon cycle, the process(es) of ___ returns carbon to the atmosphere, primarily in the form of ___.

Fossil fuel combustion and plant/animal respiration release carbon dioxide.

In plants, Gross Primary Production is equivalent to ___.

Total sunlight energy converted to chemical energy by photosynthesis.

When Mycorrhizae fungi form associations with the roots of plants, the fungus provides minerals to the plant and the plant provides carbohydrates to the fungus. What type of association is this?

Mutualism: fungi supply minerals to plants; plants supply carbohydrates to fungi.

Which is the correct order of trophic levels in terms of energy flow through a community?

Producers → primary consumers → secondary consumers.

The maximum population size an environment can support is referred to as ____.

Maximum population size an environment can support.

Which of the following phyla includes sea urchins?

Echinodermata.

Why are seeds a more adaptive structure than spores?

Seeds contain a protected embryonic plant and stored resources; spores generally consist of a single cell.

Which of the following is not a part of the pistil? B. Seeds contain a haploid cell, while spores contain a food supply. D. Seeds contain an embryonic plant, while spores contain one diploid cell.

Filament (part of the stamen).

The cuticle layer in plant tissues ___.

Nonliving waxy deposit that reduces water loss.

What is the oldest terrestrial fungal phylum? B. a non-living deposit that prevents water loss. D. is one cell layer in thickness and it contains chloroplasts.

Zygomycota (as framed by the practice exam).

The term _______ describes a bacterial virus that can establish a long-term relationship with a host cell, such that the viral genome is maintained (potentially indefinitely) in an integrated state.

Bacterial virus whose genome can be maintained long-term in a host, often integrated into its chromosome.

Koch's postulates are intended as a guide for:

Guidelines for determining which microorganism causes a particular disease.

The ability to resist phagocytosis is an important property of:

Capsules.

Which type(s) of bacteria are typically gram positive, aerotolerant aerobes that undergo fermentation?

Lactic acid bacteria.

In microscopy, resolving power is best defined as:

Ability to distinguish closely spaced objects as separate.

The cell walls of Gram (-) bacteria contain:

Peptidoglycan, Braun lipoprotein, and lipopolysaccharide.

A certain virus infects a bacterial host cell. Instead of causing the host cell to burst, the virus establishes a long-term relationship with the host, and the viral genome is maintained within the host. This relationship is called _____.

Long-term maintenance of bacteriophage genetic material in a bacterial host without immediate lysis.

Which of the following is true of all viruses?

Contain nucleic acid (DNA or RNA).

Zygospores are:

Sexual spores produced by zygomycete fungi.

Unlike disinfectants, antiseptics are formulated for use with:

Antiseptics are formulated for living surfaces.

Which of the following is true concerning the peptidoglycan of Gram-negative cells?

Present as a thin layer.

Viroids are

Short infectious single-stranded RNA molecules.

Which of the following are associated with endotoxin?

Lipopolysaccharide (LPS) of Gram-negative bacteria, including E. coli and Salmonella; can cause severe illness.

Which of the following is the major reason why viral infections are difficult to treat with chemotherapeutic agents?

Viruses rely on host-cell metabolic machinery, limiting virus-specific drug targets.

Which of the following contains nucleic acids? B. Viruses have no metabolism; therefore, no selective point of attack is present. D. Viral metabolism is similar to host metabolism.

Chromosomes, ribosomes, and plasmids.

Which of the following is present in Gram-negative cell walls and not present in Gram-positive cell walls?

Lipopolysaccharide (LPS).

Peptide interbridges are found in the cell wall structure of _________ bacteria.

Characteristic of Gram-positive peptidoglycan.

Flexible bacteria with a helical shape are called

Flexible helical bacteria.

Which statement(s) correctly describes capsules?

Help evade phagocytosis, block some phages, and retain water to prevent desiccation.

Which of the following is not true of bacterial plasmids?

Usually nonessential extrachromosomal DNA that replicates independently and may carry survival or resistance genes.

What is the purpose of X chromosome inactivation in mammals?

Dosage compensation.

The type of RNA that serves as the template for polypeptide synthesis is:

RNA template used for polypeptide synthesis.

In the Lac operon:

Lactose present and glucose low favor expression of lac structural genes.

The final step in the expression of DNA's control over cellular activity, as described in the Central Dogma, is:

Translation.

Which of the following enzymes can synthesize RNA, using DNA as a template?

RNA polymerase.

The proofreading ability of DNA polymerase I is due, in part, to:

Uses exonuclease activity to remove incorrectly incorporated nucleotides.

If # equals the haploid number in a given species, the number of DNA molecules in one cell during Metaphase II (meiosis) is:

2n DNA molecules per cell.

A nucleic acid sample was found to possess 23% adenine and 35% thymine. Based on this information the sample was:

Single-stranded DNA; the exam identifies viral single-stranded DNA.

In eukaryotes, genes with the ability to "jump" from one position within the genome to another are called:

DNA sequences capable of moving to new positions in the genome.

Single stranded human DNA fragments were incubated under reannealing conditions with single stranded DNA fragments from four different species. The percentage of ds DNA produced from these incubations is as follows: Human + species 1 = 2.2% ds DNA Human + species 2 = 6.1% ds DNA Human + species 3 = 5.3% ds DNA Human + species 4 = 1.8% ds DNA >>> From a genetic perspective, to which species are humans most closely related?

Species 2, with the highest DNA hybridization value (6.1%).

Which of the following is a rule used to determine the probability for two independent events that occur simultaneously?

Multiply probabilities of independent events occurring together.

In the bacterium E. coli, the locus OriC is the site where:

Origin where chromosomal DNA replication begins.

An organism's haploid number is known to be 4. A cell from this organism is examined microscopically, revealing a total of eight unreplicated chromosomes. The chromosomes are arranged so that a cluster of four chromosomes is present at each pole. Which stage of cell division is this?

Late anaphase of mitosis.

A stock culture of fruit flies LL RR mm is crossed with a stock culture ll rr MM. The resulting F1 flies (LlRrMm) are used in a test cross to yield the following F2 population (10,000 total): Rr Ll mm = 3715, rr ll mm = 48, Rr ll Mm = 437, RrLlMm = 52, rr Ll Mm = 719, rr ll Mm = 3785, rr Ll mm = 463, Rr ll mm = 781. >>> The total number of F2 flies exhibiting the parental phenotypes is:

7,500 flies (3,715 + 3,785).

A stock culture of fruit flies LL RR mm is crossed with a stock culture ll rr MM. The resulting F1 flies (LlRrMm) are used in a test cross to yield the following F2 population (10,000 total): Rr Ll mm = 3715, rr ll mm = 48, Rr ll Mm = 437, RrLlMm = 52, rr Ll Mm = 719, rr ll Mm = 3785, rr Ll mm = 463, Rr ll mm = 781. >>>Of the three genes being assessed, a map of the chromosome would place _____ as the middle gene.

L gene.

A stock culture of fruit flies LL RR mm is crossed with a stock culture ll rr MM. The resulting F1 flies (LlRrMm) are used in a test cross to yield the following F2 population (10,000 total): Rr Ll mm = 3715, rr ll mm = 48, Rr ll Mm = 437, RrLlMm = 52, rr Ll Mm = 719, rr ll Mm = 3785, rr Ll mm = 463, Rr ll mm = 781. The parental generation stock cultures were:

Homozygous at all three loci.

The Mendelian Principle of Segregation:

The two alleles of a gene separate during gamete formation; demonstrated by monohybrid crosses.

In the Lac operon, when lactose/allolactose attaches to the repressor protein:

Repressor releases the operator, allowing transcription of lactose-metabolism genes.

The RNA polymerase holoenzyme: B. enzymes required for lactose synthesis are produced D. lactose degradation enzymes attach to the repressor gene

Recognizes the DNA promoter region to initiate transcription.

During meiosis, replicated (twin chromatid) chromosomes line up on the spindle during:

Metaphase II.