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12

As a quick answer, yes, most human cells carry 2 copies of the genome and are known as diploid cells. One copy comes from each of your parents, so they aren't identical, but usually pretty close. Sperm and egg cells only carry one copy of the genome and are known as haploid. During fertilization the 2 cells merge their copies and make a diploid zygote. At ...


6

Genetic code and codons are always used with reference to RNA. When talking about DNA, the the sense strand of a gene is considered its sequence. The anti-sense strand though is the template for mRNA synthesis, does not represent the gene. DNA-codon table has simply U replaced by T. Apart from a wikipedia article, I don't find the term being popularly (not ...


6

You could do different things: First you could, as you say yourself, sequence the complete genomes of the strains from a biofilm and compare these with some, which do not form biofilms. This may give you an idea which genes are involved when they are present in the "biofilm genome" but not in the other. The proof would be to disrupt these genes either by ...


5

Besides viral infections there are different pathways for cells to take up dsRNA. Inside the cells these dsRNA are processed by Dicer which processes these RNAs into small interfering RNA, which play an important role in the regulation of gene activity. These pathways have mostly been researched in Drosophila and C. elegans, I am indicating where evidence ...


5

CFTR is the gene which encodes the "Cystic fibrosis transmembrane conductance regulator", which is a membrane protein. Its function is to transport chloride and other negatively charged ion like thiocyanate ions from the inside of the cell to the outside (into the extra cellular space). This happens along a gradient, meaning the ions flow from the place of ...


5

Diploid cells contain two copies of the genome. Additionally, each copy of the genome can have multiple copies of certain genes. Which can provide a level of protective redundancy. However, there are a number of potential problems with having multiple copies of portions of the genome such as trisomy disorders (e.g. Down Syndrome). Which is why therapy like ...


5

Addition to other answers. Usually a human cell is diploid. Sometimes there might be extra copies of a chromosome and this phenomenon is called aneuploidy (Downs Syndrome, Klinefelter's syndrome etc). This always has deleterious effects because of changes in stoichiometries of different gene products (dosage effect). Some other organisms also tolerate ...


4

Huntington's disease may become symptomatic starting from as low as 2 years old [1] and rarely after 55 years old [2] (yet there is evidence of onset at 65 years old [3] and even more according to newer studies). Figure: Copyright © 2004, The American Society for Experimental NeuroTherapeutics, Inc. Richard H. Myers. Huntington’s Disease Genetics. ...


4

Since only the male tail is equipped with various specialized sensory and copulatory structures that enable him to locate the vulva and successfully inseminate the hermaphrodite. Hermaphrodites can self-fertilize, but only males can cross-fertilize a hermaphrodite. sources: Wormbook: Male development C. elegans II (2nd edition): Sexual Dimorphism


4

The CFTR gene is coding a protein called CFTR (Cystic fibrosis transmembrane conductance regulator). This protein is an ion channel, which allows passive transport of the Cl- ions through the cell membrane in both directions. This allows the cells to transport water due to the active transport of Na+ ions. The Cl- ions follow the Na+ ions with passive ...


4

Vision deteriorates for both reasons, but I'm not quite sure how to separate the effects of aging from wear and tear. Cataracts are the leading cause of blindness in the world. Ways in which environment (which falls under the category of wear and tear in my book) affects cataract formation: UV light: people living at high altitudes (e.g. Tibet) have ...


4

Addition to Chris' answer. If you do not have a strain that doesn't produce biofilm then you would have to screen for the genes that are involved in biofilm production (this goes for any phenotype). In earlier times people used to do this by random mutagenesis with mutagens such as EMS (Ethyl Methanesulphonate) or UV. Nowadays it is possible to build a ...


3

There are some more places other than what Bez has already mentioned. See here. However, tagging collagen may be a problem. Collagen undergoes a lot of post-translational modifications including hydroxylation and end clipping. It forms a unique structure (triplex) and adding tags may compromise its structural integrity. You can try Masson's trichome stain ...


3

This study of the recently sequenced pine species states that 82% of genome is repetitive. This is characteristic of any complex genome, including humans. Such sequences have often been considered "junk DNA", though any scientist will tell you that just because we don't know its purpose doesn't mean it doesn't have one. That said, a good portion of repeats ...


3

In most tissues, close to 100% of DNA methylation occurs at CpG sites. This provides a straightforward mechanism for epigenetic inheritance. Since C and G are complementary, both strands have the CpG site at the same locus and methylation is either present on both strands or on neither. During replication, each daughter DNA molecule inherits a parent strand ...


3

This is very likely to be parthenocarpy, which is an “internal proliferation” and varies from an irregular fruit to an almost carbon copy of the larger pepper. What is known is that it shows up in seed lines through natural selection and is unaffected by weather, pests, or other external conditions. Please see page 27 of this document.


3

You probably mean genomic and non-genomic DNA - Plasmids are small rings of non-genomic double-stranded DNA in Bacteria. They replicate mostly indepently of the genomic DNA can can occur from a few to several hundred copies per cell. See the illustration from the Wikipedia:


3

Let's set things straight. The genomes of humans are highly similar and in general everyone shares the same genes. SNPs, or Single Nucleotide Polymorphisms, are single basepair positions in the genome in which there tend to be differences between people. This means, that instead of measuring the whole genome sequence for a person, which is very expensive and ...


2

Not to forget that simple cross breeding your plants the Mendelian way also modifies their genetic make up, as @souvik bhattacharya indicates in his comment. No equipment necessary, no chemicals, no ethical issues.


2

Wobble pairing is just a phenomenon and not a hard and fast rule. There are some justifications for why it should exist and that is why it is still called a hypothesis. And this statement is not true:"the base on the third position of the codon and that on the anticodon need not be complementary". The anticodon residue corresponding to the third residue of ...


2

Penetrance describes the frequency of a gene's expression: Penetrance refers to the proportion of people with a particular genetic change (such as a mutation in a specific gene) who exhibit signs and symptoms of a genetic disorder. (Genetics Home Reference nih.gov) More specifically: [P]enetrance is defined as the percentage of individuals with a ...


2

The comment by @fileunderwater is apt: stress-response-related genes are genes that are activated during stress, such as exposure to heat. In bacteria, for example, there are heat-shock proteins that are involved in keeping the tertiary structure of proteins (folding/3D shape) intact during periods of heat exposure. Genes encoding these heat shock proteins ...


2

Most mutations to the DNA are heritable, but not all are inherited. Mutations occur in the DNA, DNA is then replicated and transmitted to offspring (cells or organisms). Generally all mutations are heritable because they can be inherited, but some aren't - either by random chance (drift) or deleterious fitness effects (selection). Any mutation which makes ...


2

I don't know what you really mean by "heritable changes to the genome". I think you will understand why this sentence makes no sense after reading what follows. I start with some background and then try to address directly what confuses you. Short introduction to the concept of heritability The concept of heritability may have two meanings. Heritability ...


2

Mutations can be caused by much more than just recombinatory events--polymerase fidelity, DNA damage repair, even environmental factors can have a huge impact on DNA damage. While most DNA polymerases have an error rate of around one mutation per billion, there are different levels of fidelity among different polymerases (McCulloch and Kunkel, 2008). ...


2

I can understand your confusion but it all makes sense. The basic idea is that what we call the "antisense" strand is actually the one being transcribed. However, since that is in effect a mirror image, it is much simpler to think in terms of the sense strand. To take a very simple example: 5' ATG 3' <-- sense strand 3' TAC 5' <-- antisense strand ...


2

You can also try Lehninger Principles of Biochemistry...It covers all the topic except the part about cell motility...& possibly, the 1-A-g ( I'm not too sure about it)...but the book is for pretty advanced levels...& I would not recommend it as a last minute reference book..but for thorough study it's great....& of course it's my personal ...


2

To address the "reason behind the question" - no, this doesn't work as you seem to assume it does. It is the whole point of sexual reproduction to have two slightly different copies of the genome. Mutations are not "corrected" within an organism, because they are not considered a bad thing per se. Mutations are "corrected" across generations, in the sense ...


1

Stryer's Biochemistry is a great book that pretty much covers all the requirements except those in A1 - Those are basic chemistry concepts which are not covered in Stryer. Any basic chemistry book will cover that. Make sure to verify, one-by-one, that all the test subjects are covered in Stryer. This answer is just a recommendation for a great Biochemistry ...


1

One of the chief components of centrosome is γ-Tubulin. In this study the authors have reported the effect of γ-Tubulin knockout in mice. Quoting the abstract: Gamma-tubulin regulates the nucleation of microtubules, but knowledge of its functions in vivo is still fragmentary. Here, we report the identification of two closely related gamma-tubulin ...



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