Question 1

In general,diploid reproduction in S.cerevisiae occurs as a matter of chance and is regulated by environmental conditions.

Accepted Answer

In Saccharomyces cerevisiae, also known as baker's yeast, diploid cells can undergo meiosis to form haploid spores when they are subjected to nutrient depletion or other stressful environmental conditions. This process is not merely a matter of chance but is a regulated response to environmental cues, ensuring the survival of the species under unfavorable conditions.

Question 2

It takes relatively little time for a researcher to successfully develop a mutant that provides a suitable and reliable experimental system for testing a hypothesis about the impact of genes on longevity

Accepted Answer

Developing a mutant that provides a suitable and reliable experimental system for testing hypotheses about the impact of genes on longevity can be a complex and time-consuming process. It involves identifying the specific genes of interest, creating mutations in these genes, and then assessing the effects of these mutations on the organism's lifespan, all of which require significant time and resources.

Question 3

Which tough polymer of nitrogen-containing sugars forms between the bud and the parent cell of yeast after mitosis occurs?

Accepted Answer

Chitin is a tough polymer composed of nitrogen-containing sugars that forms between the bud and the parent cell of yeast after mitosis occurs.

Question 4

Determining a gene's function within the organism often starts by evaluating where and when the gene is expressed,utilizing:

Accepted Answer

In situ hybridization is a technique used to determine where and when a gene is expressed within an organism by detecting the presence of mRNA through hybridization with complementary probes. In vivo hybridization and electrophoresis are not commonly used techniques for this purpose. In situ electrophoresis does not exist as a technique.

Question 5

S)cerevisiae can exist in two chromosomal states: one containing two sets of each chromosome,known as the ______ state,and one containing one set of each chromosome,the ______ state.

Accepted Answer

Saccharomyces cerevisiae can exist in two chromosomal states; one containing two sets of each chromosome, known as the diploid state, and one containing one set of each chromosome, the haploid state.

Question 6

Weak mutations in critical genes that regulate dauer formation result in an extended adult life span.

Accepted Answer

Weak mutations in genes that regulate dauer formation have been shown to extend adult life span in various model organisms, such as Caenorhabditis elegans. This is thought to be due to changes in cellular processes and metabolism that promote longevity.

Question 7

General recombination is an essential part of meiosis in S.cerevisiae,but it also gives rise to potentially damaging ______ rDNA circles.

Accepted Answer

General recombination during meiosis in S.cerevisiae can give rise to extrachromosomal rDNA circles which can cause genomic instability and potentially be damaging to the cell. Plasmids are not typically involved in meiosis in S.cerevisiae, and homologous recombination is a normal and necessary part of the process. Chromosomal recombination can occur, but it would not lead to the formation of extrachromosomal circles.

Question 8

Morphological and biochemical alterations in the C.elegans dauer increase its resistance to stress and thereby increase its chance of survival.These changes include all of the following except:

Accepted Answer

Decreasing the concentration of endogenous antioxidants would actually decrease the dauer's resistance to stress, so this change is not observed. The other options are correct as increasing cuticle thickness and closing the mouth help to prevent water loss, and increasing the concentration of endogenous antioxidants helps to protect against oxidative stress.

Question 9

After separation of the new yeast cell from the mother cell,a circular chitin residue known as the ______ remains permanently on the surface of the mother cell.

Accepted Answer

The answer of After separation of the new yeast cell...

Question 10

Binding of NAD⁺ to the SIR2 protein causes activation of the histone deacetylase and compaction of the chromatin,silencing of the rDNA locus,reduction of the budding process,and an extended replicative life span for the yeast.

Accepted Answer

Binding of NAD⁺ to SIR2 protein does indeed cause activation of the histone deacetylase and leads to changes such as chromatin compaction, rDNA locus silencing, reduction in budding process, and extended replicative life span in yeast.

Question 11

When budding yeast cells enter a nondividing state,called the ______ phase,they remain metabolically active.

Accepted Answer

The stationary phase is a nondividing state where yeast cells remain metabolically active.

Question 12

The method of applying an electrical current to a semi-solid material in order to separate molecules or compounds is known as:

Accepted Answer

The method described in the question is commonly known as gel electrophoresis, where an electrical current is applied to a gel matrix (usually made of agarose or polyacrylamide) to separate molecules such as DNA, RNA, or proteins based on their size and charge. Gel fluorescence is not a commonly used term in scientific literature or practice. Electro-separation is too broad and could refer to various processes involving electricity to separate materials. Polymerase chain reaction (PCR) is a technique used to amplify DNA, and does not involve applying an electrical current to a semi-solid material.

Question 13

A dauer is a worm in which development is halted at larval stage 3;the dauer is metabolically active but reproductively silent

Accepted Answer

This is correct. A dauer is a special developmental stage in nematodes where they cease normal development and instead form a metabolically active, long-lived, and stress-resistant state. The dauer stage is typically reached in response to harsh environmental conditions, and dauer worms are reproductively arrested until conditions improve. In the laboratory, researchers can induce the formation of dauer larvae in nematodes as a way to study various aspects of developmental biology and physiology.

Question 14

The hybridization technique that uses pieces of glass about the size of a postage stamp that are embedded with single-stranded DNA sequences from specific genes with known functions is called:

Accepted Answer

The description matches DNA microarrays, which are also sometimes called DNA chips or gene chips. The technique involves using a small piece of glass or silicon that has been etched with thousands of microscopic spots, or features, each containing a different single-stranded DNA sequence that can hybridize with DNA or RNA from a sample. This allows researchers to detect and analyze the expression of many genes at once.

Question 15

The amount of food in the yeast's environment seems to link reproduction to longevity.Food abundance results in ______ rates of reproduction and ______ longevity.

Accepted Answer

When there is an abundance of food in the environment, the yeast reproduces at a high rate but has decreased longevity. This is because the yeast uses its resources to reproduce as much as possible, rather than investing in cellular maintenance and repair, which leads to a shorter lifespan. On the other hand, when there is a limited amount of food, yeast reproduce less frequently but have increased longevity, as they invest more resources in cellular maintenance and repair to maintain their survival.

Question 16

The SIR2 protein is a histone acetylase that causes compaction of the chromatin and gene silencing.

Accepted Answer

SIR2 protein is a histone deacetylase that causes chromatin decompaction and gene expression.

Question 17

Cloning of the daf-2 gene revealed that it encodes a transmembrane receptor protein that has homology with a(n)_____ receptor found in other species.

Accepted Answer

The sentence directly states that cloning of the daf-2 gene revealed it encodes a transmembrane receptor protein with homology to an insulin/insulin-like growth factor (IGF-1) receptor found in other species, making option D the correct choice. Option A refers to a complex family, not a receptor protein. Option B refers to a family of transcription factors, not a receptor protein. Option C refers to an enzyme, not a receptor protein.

Question 18

Select the two sexual forms of C.elegans.

Accepted Answer

C. elegans has two sexual forms: hermaphrodite and male. Hermaphrodites are able to self-fertilize, while males are only able to fertilize hermaphrodites. Choice B is incorrect because diploid and haploid describe ploidy levels, not sexual forms. Choice C is incorrect because C. elegans does not have a female sexual form. Choice D is incorrect because C. elegans does not have an asexual sexual form.

Question 19

The single-cell eukaryotic organism S.cerevisiae is a good model organism for aging research because of all the following characteristics except:

Accepted Answer

S.cerevisiae is a unicellular organism and therefore does not have a well-defined neural system.

Question 20

Enzymes that cleave the DNA at specific sequences are called:

Accepted Answer

Enzymes that cleave the DNA at specific sequences are called restriction nucleases. These enzymes are commonly used in molecular biology to cut DNA at specific sites, which allows for the creation of recombinant DNA molecules and the study of DNA sequences.

Quiz 5: Genetics of Longevity

In general,diploid reproduction in S.cerevisiae occurs as a matter of chance and is regulated by environmental conditions.

It takes relatively little time for a researcher to successfully develop a mutant that provides a suitable and reliable experimental system for testing a hypothesis about the impact of genes on longevity

Which tough polymer of nitrogen-containing sugars forms between the bud and the parent cell of yeast after mitosis occurs?

Determining a gene's function within the organism often starts by evaluating where and when the gene is expressed,utilizing:

S) cerevisiae can exist in two chromosomal states: one containing two sets of each chromosome,known as the state,and one containing one set of each chromosome,the state.

Weak mutations in critical genes that regulate dauer formation result in an extended adult life span.

General recombination is an essential part of meiosis in S.cerevisiae,but it also gives rise to potentially damaging ______ rDNA circles.

Morphological and biochemical alterations in the C.elegans dauer increase its resistance to stress and thereby increase its chance of survival.These changes include all of the following except:

After separation of the new yeast cell from the mother cell,a circular chitin residue known as the ______ remains permanently on the surface of the mother cell.

Binding of NAD⁺ to the SIR2 protein causes activation of the histone deacetylase and compaction of the chromatin,silencing of the rDNA locus,reduction of the budding process,and an extended replicative life span for the yeast.

When budding yeast cells enter a nondividing state,called the ______ phase,they remain metabolically active.

The method of applying an electrical current to a semi-solid material in order to separate molecules or compounds is known as:

A dauer is a worm in which development is halted at larval stage 3;the dauer is metabolically active but reproductively silent

The hybridization technique that uses pieces of glass about the size of a postage stamp that are embedded with single-stranded DNA sequences from specific genes with known functions is called:

The amount of food in the yeast's environment seems to link reproduction to longevity.Food abundance results in rates of reproduction and longevity.

The SIR2 protein is a histone acetylase that causes compaction of the chromatin and gene silencing.

Cloning of the daf-2 gene revealed that it encodes a transmembrane receptor protein that has homology with a(n) _____ receptor found in other species.

Select the two sexual forms of C.elegans.

The single-cell eukaryotic organism S.cerevisiae is a good model organism for aging research because of all the following characteristics except:

Enzymes that cleave the DNA at specific sequences are called:

Quiz 5: Genetics of Longevity

In general,diploid reproduction in S.cerevisiae occurs as a matter of chance and is regulated by environmental conditions.

It takes relatively little time for a researcher to successfully develop a mutant that provides a suitable and reliable experimental system for testing a hypothesis about the impact of genes on longevity

Which tough polymer of nitrogen-containing sugars forms between the bud and the parent cell of yeast after mitosis occurs?

Determining a gene's function within the organism often starts by evaluating where and when the gene is expressed,utilizing:

S) cerevisiae can exist in two chromosomal states: one containing two sets of each chromosome,known as the ______ state,and one containing one set of each chromosome,the ______ state.

Weak mutations in critical genes that regulate dauer formation result in an extended adult life span.

General recombination is an essential part of meiosis in S.cerevisiae,but it also gives rise to potentially damaging ______ rDNA circles.

Morphological and biochemical alterations in the C.elegans dauer increase its resistance to stress and thereby increase its chance of survival.These changes include all of the following except:

After separation of the new yeast cell from the mother cell,a circular chitin residue known as the ______ remains permanently on the surface of the mother cell.

Binding of NAD+ to the SIR2 protein causes activation of the histone deacetylase and compaction of the chromatin,silencing of the rDNA locus,reduction of the budding process,and an extended replicative life span for the yeast.

When budding yeast cells enter a nondividing state,called the ______ phase,they remain metabolically active.

The method of applying an electrical current to a semi-solid material in order to separate molecules or compounds is known as:

A dauer is a worm in which development is halted at larval stage 3;the dauer is metabolically active but reproductively silent

The hybridization technique that uses pieces of glass about the size of a postage stamp that are embedded with single-stranded DNA sequences from specific genes with known functions is called:

The amount of food in the yeast's environment seems to link reproduction to longevity.Food abundance results in ______ rates of reproduction and ______ longevity.

The SIR2 protein is a histone acetylase that causes compaction of the chromatin and gene silencing.

Cloning of the daf-2 gene revealed that it encodes a transmembrane receptor protein that has homology with a(n) _____ receptor found in other species.

Select the two sexual forms of C.elegans.

The single-cell eukaryotic organism S.cerevisiae is a good model organism for aging research because of all the following characteristics except:

Enzymes that cleave the DNA at specific sequences are called:

S) cerevisiae can exist in two chromosomal states: one containing two sets of each chromosome,known as the state,and one containing one set of each chromosome,the state.

Binding of NAD⁺ to the SIR2 protein causes activation of the histone deacetylase and compaction of the chromatin,silencing of the rDNA locus,reduction of the budding process,and an extended replicative life span for the yeast.

The amount of food in the yeast's environment seems to link reproduction to longevity.Food abundance results in rates of reproduction and longevity.