Explore BrainMass

DNA, Chromosomes and the Genomes

Biology problem

If a man with a red-colorblindness (a sex-linked trait) marries a normal woman, would you expect to see the trait expressed in their children? Diagram the cross below to support your answer:

Biology problem

2.) A line of Drosophila melanogaster with ebony body and sepia eyes (line A) is crossed to a line with tan body and red eyes (line B). The F1 are all tan-bodied, red-eyed, and normal-winged. What proportion of gametes produced by line A have the dominant allele for both loci?_____________ What proportion of the gametes p

New phenotypes

Please help with the following problems. Provide step by step calculations. 1. One form of color blindness in humans is caused by a sex-linked recessive mutant gene (c). A woman with normal color vision (c+) and whose father was also color-blind marries a man of normal vision whose father was also color-blind. What proport

Solving a DNA Problem

Why a defendant's genes should be considered as a factor in the criminal behavior. Why a defendant's genes do not excuse criminal behaivor.

Proposed Genetics Model and Results

1. In peas, the chemical pisatin is associated with defense against parasitic fungi: normal plants are resistant to fungi and contain pisatin. Two pure lines were obtained, both of which lacked pisatin and were highly susceptible to fungal attack Line 1 was from California and line 2 was from Sweden. The lines were investigated

DNA sequence motif that is bound by CBF1

I have 5 sequenced genes, including the punitive promotor region of each gene. All are involved in the cold acclimation process in arabidopsis. Each is expressed only when the temperature falls below a certain point. the specific transcripition factor CBF1 binds somewhere between -200 and -250 of the genes to initiate transcrip

Dominant traits/recessive traits

Pattern baldness in humans is controlled by a single autosomal locus with two alleles (B and B'), but pattern baldness is a sex-influenced phenotype: baldness is dominant in males (BB and BB' males become bald), but recessive in females (only BB females become bald). if a population is in Hardy-Weinberg equilibrium for this lo

Examination of Polygenic Traits

In the future, aliens who have invaded earth are conducting a survey of teenagers. When examining body modifications, they conclude that piercing is a polygenic trait. They reached this conclusion by examining only the number of piercings in a teenager, and the number of piercings in their parents. Why might they conclude that t

AP Biology: Practice Test Review

AP Biology Test Review We are doing a mitosis and meiosis lab. I need help on these concept questions. 1. Why is it more accurate to call mitosis "nuclear replication" rather than "cellular division"? 2. Explain why the whitefish blastula and onion root tip are selected for a study of mitosis. 3. List three major diff

Specify the location and function of the centromere...

1. Specify the location and function of the centromere. The centromere is a region of a eukaryotic chromosome where the kinetochore is assembled thus; it is the site where spindle fibers of the mitotic spindle attach to the chromosome during mitosis. (Centromeres are highly complex chromosomal substructures involved in essenti

Chromatin packaging: Example problem

Explain the relationship between chromatin packaging and transcription rates. Name two different types of chromatin modification associated with changes in gene expression. Indicate how the DNA or protein is modified chemically and how the modification affects the chromatin structure (that is, does the modification relax or co

Chi squared analysis

In corn, colored aleurone (R) is dominant to colorless aleurone (r), and green plant color (G) is dominant to yellow plant color (g). two plants, each heterozygous for both characteristics, are testcrossed to homozygous recessives, and their progeny are combined to produce the following totals: colored green 100 colored ye

Restriction sites

In a restriction mapping experiment using the plasmid P (ST), you cleave the circular plasmid with the restriction enzymes Xbal, Asp718, BamHI and EcoRI individually and in various combinations with each other. You obtain DNA fragments with the following sizes: Enzymes used size of DNA fragments (bp) BamHI, EcoR


Please answer the following questions on FUNGI (attached). --- LAB 15-A 1- Do the hyphae of zygomycetes contain cross walls (sept)? 2- How would you describe the hyphae of Zygomycetes? LAB 15-B 1- Describe the hyphae of pezira 2- Are ascospores the result of asexual or sexual reproduction? LAB 15-C 1

Meiotic Nondisjunction

Meiotic nondisjunction events will create aneuploid gametes. Describe (with figures) normal Drosophila male meiotic segregation of the sex chromosomes. Then describe all possible outcomes if a Meiosis-I nondisjunction occurs; then do the same for Meiosis-II nondisjunction.

Reverse Transcriptase

What is reverse transcriptase and why do we find multiple copies of it in the human genome?


1.The basic differences between RNA and DNA are: a.The organic bases only b.Bases, ribose units, and the phosphodiester linkage c.Bases, ribose units, and the glycosidic bond type d.Bases and the ribose units only. 2.The solubility characteristics of the pyrimidine or purine bases and the corresponding nucleosides di


Genetically speaking, what do we know about birth defects caused by thalidomide, cocaine and alcohol?


What do we know about DNA damage caused by nuclear radiation (the Hiroshima and Nagasaki atomic bombs)?

Genetics in Human Cells

What may cause human cells to contain 45 or 47 chromosomes instead of 46and what is Down syndrome?

Miscellaneous questions

1. A population of grasshoppers in the Kansas prairie has two color phenotypes, green and brown. Typically, the prairie received adequate water to maintain healthy, green grass. Assume a bird that eats grasshoppers moves into the prairie. How will this affect natural selection of the grasshoppers? How might this chang

DNA etc.

Discuss one agricultural and one medical application of biotechnology. Describe how the technique of gene therapy might help someone with an inherited genetic disease. Discuss some of the bioethical concerns related to screening for genetic diseases.

Polymerase Chain Reaction - PCR

I am legally blind and therefore, I cannot see the board in the classroom, and I also cannot read regular print because my vision is too low. That is why I need your help in solving the review problems below. Please send me the correct answers to all nine problems and write large and clear, using high contrast such as a thic

SCI Biology Essay - Help with ideas

Today, scientific advances are being made at an astounding rate, and nowhere is this more evident than in our understanding of the biology of heredity. Using DNA as a starting point, do you believe there are limits to the knowledge people should acquire? Defend your answer. Because genetics is important to so many aspects of hu