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If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is haploid (n) contains 1C of DNA. A DNA microarray (also called a DNA chip) can be used to ________. A) mutate genes of interest B) […]

Assume that a trait is caused by the homozygous state of a gene that is recessive and autosomal. Nine percent of the individuals in a given population express the phenotype caused by this gene. What percentage of the individuals would […]

Given that a human normally contains 46 chromosomes, give the chromosome number for each of the following conditions: Turner syndrome (female, no Barr bodies) Klinefelter syndrome (male, one Barr body) Triploid Down syndrome (trisomic) Trisomy 13 Present a general definition […]

How does a polytene chromosome differ from a typical eukaryotic chromosome? What two experimental procedures allowed deciphering of the ordered triplet assignments of the genetic code? Answer: the triplet binding assay and the use of repeating RNA polymers with known […]

What is an allele-specific oligonucleotide? What are minisatellites and microsatellites? Answer: Both are highly repetitive, relatively short DNA sequences. Which protein is responsible for the initial step in unwinding the DNA helix during replication of the bacterial chromosome? Answer: DnaA […]

The relationship between codon and anticodon can be characterized as involving ________. A certain type of congenital deafness in humans is caused by a rare autosomal dominant gene. In a mating involving a deaf man and a deaf woman, could […]

When a bacteriophage genome incorporates itself into the chromosome of the host, that phage genome is referred to as a(n) ________. Name the polyploid condition that is formed from the addition of an extra set of chromosomes identical to the […]

Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal complement but one (extra) chromosome 21. Although fertility is reduced in both sexes, females have higher fertility rates than males. Van Dyke et al. (1995; Down Syndrome […]

Tightly curled hair is caused by a dominant autosomal gene in humans. If a heterozygous curly-haired person marries a person with straight hair, what phenotypes (and in what proportions) are expected in the offspring? A color-blind woman with Turner syndrome […]

Cotransduction of genes is an indication that the genes are linked. A bivalent at pachytene contains four chromatids. Answer: TRUE Translocations may be pericentric or paracentric. Answer: FALSE For a given locus, in a population with two alternative alleles, the […]

Give a brief definition of a homeobox. Two forms of hemophilia are determined by genes on the X chromosome in humans. Assume that a phenotypically normal woman whose father had hemophilia is married to a normal man. What is the […]

List four base triplets that are clearly responsible for punctuation (initiation, termination). A fundamental property of DNA’s nitrogenous bases that is necessary for the double-stranded nature of its structure is ________. Answer: complementarity Assume that a dihybrid F2 ratio, resulting […]

Provide an overview of the structure of Z-DNA. Immediately after fertilization of a Drosophila egg, the zygote nucleus undergoes a series of divisions. Subsequent nuclear migration generates a(n) ________. A) syncytium B) maternal effect C) homeodomain D) zygote E) cleavage […]

Describe the value of using twins in the study of questions relating to the relative impact of heredity versus environment. Assuming one mutational event in a gene, on average, which of the following mutagens or mutational conditions would be expected […]

Three investigatorsNsslein-Volhard, Wieschaus, and Lewiswon the Nobel Prize for physiology and medicine in 1995 for work they did in 1970 with Drosophila. Briefly describe their findings. List two major differences between RNA and DNA at the level of the nucleotide. […]

In the early part of the twentieth century, Nilsson-Ehle and others described experiments showing that multiple loci may be involved in the inheritance of certain traits. Such patterns are often called ________. What anatomical structure is responsible for the transfer […]

Mutations in the selector genes sometimes form structures in the wrong segment, transforming the antenna of a fly into a leg, for example. What are such mutations called? During development, many genes act in such a way as to decrease […]

How many different kinds of gametes can be produced by an individual with the genotype AABbCCddEeFf? What does the term genetics mean? Answer: Genetics is a subdiscipline of biology concerned with the study of heredity and variation at the molecular, […]

Recombinant DNA technology is dependent on a particular class of enzymes, known as ________ that cuts DNA at specific nucleotide sequences. Which term is given to the measure of the proportion of offspring that a particular phenotype will contribute to […]

To produce recombinants in bacteria, one crossover is better than two. Genomic anticipation refers to observations that a genetic disorder occurs at an earlier age in successive generations, whereas genetic imprinting occurs when gene expression varies depending on parental origin. […]

What are LINES? In what way can loss of heterozygosity lead to cancer? Answer: Loss of heterozygosity occurs when a cancer-producing gene that exists in the heterozygous state becomes exposed through deletion, mutation, recombination, uniparental disomy, or chromosomal aberration. Such […]

DNA replication in vivo requires a primer with a free 3″ end. What molecular species provides this 3″ end, and how is it provided? Describe the positive control exerted by the catabolite activating protein (CAP). Include a description of catabolite […]

What term is used to describe genetic exchange at equivalent positions along two chromosomes with substantial DNA sequence homology? What method might be used to study a knockout mouse that, by virtue of the lost gene or genes, generates a […]

RNA processing occurs when amino acids are removed from nascent proteins. Which of the following organelles are involved in the general category of organelle heredity? A) mitochondria and chloroplasts B) golgi and nuclei C) lysosomes and peroxisomes D) factors and […]

Mutations may exert a variety of effects on living systems. List at least three categories of mutations based on their biological effects. Name two evolutionarily significant benefits of meiosis that are not present in mitosis. Answer: reshuffling of homologous chromosomes […]

What is ELSI? How many Barr bodies would one expect to see in cells of Turner syndrome females and Klinefelter syndrome males? Answer: zero and one, respectively Given that the origin of replication is fixed in E. coli, what signals […]

The term spliceopathy would be a reasonable term to signify a genetic condition caused by a defect in the regulation of RNA splicing. Traits such as height, general body structure, skin color, and some behavioral traits are probably caused primarily […]

Conservation of amino acid sequence among distantly related groups of organisms is suggestive of an important function of that sequence. Restriction endonucleases typically recognize palindromic DNA sequences and often generate “sticky ends” or single-stranded DNA overhangs at cut sites. Answer: […]

Prokaryotic and eukaryotic ribosomes are structurally and chemically identical. Doubling the chromosomes of a sterile species hybrid with colchicine or cold shock is a method used to produce a fertile species hybrid (amphidiploid). Answer: TRUE Heterogeneous nuclear RNA is a […]

Describe the conceptual basis for constructing biochemical pathways using nutrient supplement experiments with Neurospora. List the components of a nucleosome. Answer: Histones H2A, H2B, H3, and H4 exist as two types of tetramers: (H2A)2 + (H2B)2 and (H3)2 + (H4)2. […]

Research dealing with which human blood disorder was instrumental in linking the genotype to a specific phenotype, and what conclusion was reached? Lysogeny is an important phenomenon in bacteria and phages. Briefly describe lysogeny (using labeled diagrams if helpful). Answer: […]

In contrast with euchromatin, heterochromatin contains more genes and is earlier replicating. Transcription factors are proteins with at least two functional domains”one that binds to DNA and one that binds to RNA polymerase or to other transcription factors. Answer: TRUE […]

S phase is the part of interphase when DNA duplication takes place. An endonuclease is involved in removing bases sequentially from one end of DNA or the other. Answer: FALSE With multiple alleles, there can be more than two genetic […]

How many kinds of gametes will be expected from an individual with the genotype PpCcTTRr? In the polymerase chain reaction, what is the purpose of the initial high temperature? What is the purpose of cooling in the second step? Answer: […]

In the past decades, direct-to-consumer (DTC) genetic tests have become widespread. Are such tests approved by the Food and Drug Administration? How many gene pairs are involved in generating a typical 1:4:6:4:1 ratio? Answer: two How are electrical impulses propagated […]