As we learn more about genetics, this begins to look like an overly simplistic view of the concept of gene. The exact definition of the term gene is in debate at the moment, as is the use of the term at all in the future. The discovery of very short RNA's (miRNA, siRNA's) which influence gene expression (without translation into peptides) are part of this debate.
A gene is a unit of heredity in a living organism. It is normally a stretch of DNA that codes
for a type of protein or for an RNA chain that has a function in the organism. All proteins and functional RNA chains are specified by genes. All living things depend on genes. Genes hold the information to build and maintain an organism's cells and pass genetic traits to offspring. A gene is a unit of in a living organism. It is normally a stretch of DNA that codes for a type of protein or for an RNA chain that has a function in the organism.
Genes hold the information to build and maintain an organism's cells and pass genetic traits to offspring. A gene is a part of a DNA molecule that codes for a particular trait of an organism. It provides instructions on how to make a polypeptide. For example, one gene may code for the production of tyrosinase, which is an enzyme (protein) used in the synthesis of melanin (a pigment responsible for dark colors in skin and fur).
By the traditional definition, a gene is 'transcribed' into mRNA which is then 'translated' into a protein, which will produce the desired effect in an organism's cell. Some genes may contain instructions for the production of RNA that is not translated into a protein, such as tRNA, rRNA, miRNA and siRNA.
In essence, a gene is a section of a DNA molecule that has a unique and specific biological function.
A chromosome is a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order. It is also known as tightly wound DNA. It is a structure that DNA wraps around.
A chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.
Chromosomes vary widely between different organisms. The DNA molecule may be circular or linear, and can be composed of 10,000 to 1,000,000,000 nucleotides in a long chain.
Cells may contain more than one type of chromosome; for example, mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosomes.
Chromosomes are the essential unit for cellular division and must be replicated, divided, and passed successfully to their daughter cells so as to ensure the genetic diversity and survival of their progeny.
Chromosomal recombination plays a vital role in genetic diversity. If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe and die, or it may aberrantly evade apoptosis leading to the progression of cancer.
In practice "chromosome" is a rather loosely defined term. In prokaryotes and viruses, the term genophore is more appropriate when no chromatin is present. However, a large body of work uses the term chromosome regardless of chromatin content. The simplest genophores are found in viruses: these DNA or RNA molecules are short linear or circular genophores that often lack structural proteins.
Chromosomal DNA encodes most or all of an organism's genetic information; some species also contain plasmids or other extrachromosomal genetic elements.
Structure in nucleus made of DNA and protein. Sections of a chromosomes are genes.
structure in a cell's nucleuse thaat contians genetic material
A chromeosome is organized structure of DNA and protein that is found in cells.
coiled strands of genetic material
coiled strands of genetic material
a form of a gene apex
Basically is genetic info.
Different organisms have different types of chromosomes.
In bacteria (prokaryotic cells) a chromosome consists of a loop of DNA; it has no end. Along the length of the DNA are segments called genes, which contain information that the cell uses for growth and development. Most bacteria have only one chromosome, but some have more (the cholera organism Vibrio cholerae has two).
In eukaryotic cells, chromosomes are linear (they have two ends). The DNA is associated with proteins called histones. There is always more than one chromosome in a eukaryotic cell. After cell division and before DNA replication, there is only one molecule of DNA in each chromosome. After DNA replication, there are two DNA molecules in each chromosome; these are separated at the next cell division. In higher organisms, including humans, genes make up only part of the DNA. * * *
A chromosome is a single large macromolecule of DNA, and constitutes a physically organized form of DNA in a cell. It is a very long, continuous piece of DNA. * * * A chromosome refers to the colored thread observed localized within the nucleus. It is the genetic information carrier, and it may be extended (in interphase) or highly condensed (during mitosis or meiosis). The number of chromosomes is species-specific and if any alteration occurs it leads to disease condition or move forward towards evolution. In humans the total number of chromosomes is 46 or 23 pairs; mouse has 44 or 22 pairs; Onion - 16 or 8 pairs; Drosophila - 8 or 4 pairs. A chromosome after DNA replication has a pair of threads called chromatids held together by a primary constriction called a centromere. Chromatids consists of supersolenoid and scaffold structure followed by solenoid structure. Solenoid structure is formed by compaction of polynucleotides bound by histones and non-histone proteins. It leads to a fundamental structure called a nucleosome which consists of a nucleic acid part and a protein part. The protein part consists of positively-charged histones rich in lysine, arginine, and glycine. Histones consists of core subunit made of octamer made of 2 copies of H2A, H2B, H3 and H4. Linker histone H1 connects 2 nucleosomes. Chromosomes are classified based on various criteria: 1) The chromosomes which are common to both males and females are referred to as autosomes or body chromosomes and the chromosomes which determine the sex of an organism are called sex chromosome or allosomes (look dissimilar). In humans we have 22 pairs of autosomes and 1 pair of sex chromosomes (X and Y chromosomes). 2) Classified based on the position of centromere or primary constriction. The either sides of the centromere is referred to as arms (p- petite or short arm; q - quadran or long arm). When p=q (V shaped) - metacentric chromosome; When p<=q (L shaped) - submetacentric chromosome;When p<<< 3) Chromosomes are classified based on the banding pattern. Human chromosomes are classified into 7 groups A - G. A - 1-3; B - 4,5; C - 6-12, X; D - 13-15; E - 16 - 18; F - 19, 20; G - 21, 22, Y. Humans do not have any telocentric chromosomes. He has 5 pairs of acrocentric chromosomes (13 - 15, 21,22).
Chromosomes are structures composed of DNA coiled tightly around proteins called histones. In eukaryotic cells chromosomes are located in the cell nucleus. Chromosomes control the cell's activities and heredity.
When two nuclei have formed
a sperm or egg cell produced by meiosis
In plants, a new cell wall forms to split the cell
Using the Polymerase Chain Reaction, scientists can amplify even the smallest amount of DNA, by constant cycles of separation and replication.
Mitosis is not part of interphase. Neither is cytokineses.
They pull the cell membrane in.
They Split The Cell During Cytokinesis.
He showed that cells contain a transforming factor.
Scientists did not know how traits were inherited.
the baby is a female
it would prevent tumor cells from reproducing.
If crossing over didn't happen during meiosis in humans, the haploid daughter cells would all have the same genes. The crossing over creates variation and causes each daughter cell to have slightly different genes.
mitosis only has to do with celluar reproduction
meiosis has to do with sex cells reproducing
Mitosis creates new cells that are used for development, repair, asexual reproduction and growth. Meiosis creates cells in order for organisms to reproduce sexually.
64 - Apex
they have less genetic diversity in their population
the likelihood that something will happen