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Chromosomes
Chromosomes contain the genetic material DNA
1,309 Questions
What do a cells chromosomes contain?
If we use the word "chromatid", there are always two. (As with twins!)
In a eukaryotic cell immediately after cell division (mitosis or meiosis), each chromosome contains only one DNA molecule.
If the cell is preparing for a subsequent division, then midway through interphase the DNA replicates. Now there are two molecules of DNA in each chromosome.
At the start of the following division, in prophase, the chromosomes condense, and the two DNA molecules, with their many associated proteins, become visible under a light microscope as sister-chromatids.
Why can female only pass only an x chromosome to offspring?
The female can only pass on ONE "X". an XX female offspring must get the second X from the father.
What does chromosome 21 provide?
Usually humans have 46 chromosomes, divided into 23 pairs within each cell, one copied from each parent.
Chromosome 21 is the smallest and the second human chromosome to be sequenced.
Many genetic conditions are related to changes in particular genes on this chromosome
including Cancers, Downs Syndrome and Alzheimer's Disease
Changes in the structure in the number of copies of a chromosome may also cause problems with health and development.
Cancer For example -translocation in chromosomes 12 and 21 have been linked to Lymphoblastic Leukemia whilst links between translocation of 8 and 21 Acute Myeloid leukemia.
Downs Syndrome -a chromosomal condition that, in most cases is caused by trisomy 21 (each cell has 3 copies instead of the normal 2).
How many pairs chromosomes does a cheetah have?
cheetahs have 38 chromosomes in there body just like other cat like animals like the feared lion, and a savage tiger. happy now!
Chromatin and chromosomes similarities?
Chromatin is intertwinted mass of fine thread-like structure made of DNA and protein. During cell division (mitosis and meiosis), chromatin condenses to form thicker rod-like structures called chromosomes. Each chromosome consists of two similar halves called chromatids. Formation of chromosomes having two similar halves or chromatids is meant for equitable distribution of chromatin which is hereditary material.
How many chromosomes does a hawk have?
About 63% of known bird species have a diploid chromosome number (2n) of 74-86. A further 24% have 2n = 66-74.
Extremes at the lower end of the spectrum are the trumpeter hornbill Ceratogyman bucinator and stone curlew Burhinus oedicemus (with 2n = 40 and 42 respectively). The highest recorded chromosome number in birds is in the common kingfisher Alcedo athis (2n = 132 or 138) or the Grey (or Southern) Go-away bird Corythaixoides concolor (2n = 136-142). Understandably, accurate chromosome counts become difficult with these numbers. [Source: Christidis, 1990, Animal Cytogenetics 4, Chordata 3 B: Aves]
In general, chromosome number in birds is both higher than in most other vertebrates, and less variable. The typical avian karyotype is composed of macro- and microchromosomes, with a continuous size distribution. Exceptions include the falcons and parrots, where chromosomal fusions and other rearrangements are common, and have reduced chromosome number and size variation in these groups as a whole.
For a recent review of this topic, see: The evolution of the avian genome as revealed by comparative molecular cytogenetics, Cytogenet Genome Res. 2007;117(1-4):64-77
What is the term used for the number of chromosomes found in a cell?
there are no chromosomes???????? mitosis needs them first....?
What are the Different types of chromosomes?
what do you mean by types???? Chromosomes are the organized form of DNA found in cells. Chromosomes contain one very long, continuous piece of DNA, which contains many genes, regulatory elements and other intervening nucleotide sequences. A broader definition of "chromosome" also includes the DNA-bound proteins which serve to package and manage the DNA. The word chromosome comes from the Greek χρῶμα (chroma, color) and σῶμα (soma, body) due to their property of being stained very strongly with vital and supravital dyes. Chromosomes vary extensively between different organisms. The DNA molecule may be circular or linear, and can contain anything from tens of kilobase pairs to hundreds of megabase pairs. Typically eukaryotic cells (cells with nuclei) have large linear chromosomes and prokaryotic cells (cells without nuclei) smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosome in addition to the nuclear chromosomes. In eukaryotes nuclear chromosomes are packaged by proteins into a condensed structure called chromatin. This allows the massively-long DNA molecules to fit into the cell nucleus. The structure of chromatin varies through the cell cycle, and is responsible for the organisation of chromosomes into the classic four-arm structure during mitosis and meiosis. "Chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. These small circular genomes are also found in mitochondria, and chloroplasts, reflecting their bacterial origins. The simplest chromosomes are found in viruses: these DNA or RNA molecules are short linear or circular chromosomes that often lack any structural proteins.
Chromosomes need to be distributed to the daughter cells so precisely because the daughter cells need the the genetic information in the chromosomes. If a chromosome is missing in one of the daughter cells this could prevent the cell from producing a needed protein to survive or something to that effect.
What household item represents chromosome?
Nucleus: a map. It codes for different things and is almost like a set of directions.
Ribosome: LEGOs. Ribosomes gather together amino acids and make proteins out of these groups!
Endoplasmic Reticulum: a tunnel. Cars are the "proteins and lipids" and the tunnel is the ER
Golgi Body: LEGOs again! Lets say you made a car, a house, and a tree out of LEGOs. The Golgi would make these three things into a neighbourhood!
Lysosome: a stomach. A lysosome takes in food and breaks it down for the cell.
Vacuole: a closet. It stores random stuff!
Mitochondria: a battery. Provides power for everything else
Chloroplast: a solar panel. It collects light and turns it into energy.
Cytoskeleton: a human skeleton. Holds shape while it carries out life processes
Do you body cells of humans have 46 pairs of chromosomes?
A cell that contains both copies of each chromosome is called a Diploid cell.
What conditions can aneuploidy of sex chromosomes cause?
An example of aneuploid condition is Down syndrome, is due to three copies of choromosome 21 or trisomy 21.
What can chromosomes represent in a city?
The most basic analogy for chromosomes is that they are the the blueprints since they are large bundles of DNA which is the actual information on your body and how it is constructed, and a blueprint is a detailed plan on how something is constructed.
What is the Biological term for Nucleic acid that is a constituent of chromosomes?
deoxyribonucleic acid
When chromosomes are copied what are the two copies are called?
I think it's called Interphase? idk BUT...... it's a question on my homework lol
In what phase does chromosomes condense and become visible?
The chromosomes in a cell's nucleus are only visible during the part of the cell cycle known as prophase. Prophase is the stage of mitosis in which chromatin condensation occurs.
What has the largest number of chromosomes in the animal kingdom?
Hi, i think OI answered this one.
there is a species of fern that has a few thousand base pairs.
They believe that number of base pairs in not linked to intelligence or complexity, simply linked to age of evolution (my view on it) so the longer the species has lived and evolved the more basepairs it seems to have.
What is the role of chromosomes in cell division?
Hello my name is Tigress and I am 4 years old.
> They carry hereditary information in the genes from parents to off springs.
> They help cell grow, divide, maintain itself by directing synthesis of proteins.
> Control cell metabolism by directing the formating of necessary proteins.
> They undergo crossing over and mutations and thus contribute to the evolution.
> They guide cell differentiation during development.
> The sat chromosomes form nucleoli in daughter cells at nucleoli organization.
Why The reduction of the chromosome number during meiosis is most important?
maintaining the chromosome number during sexual reproduction
What stage are Chromosomes duplicated?
technically the chromosomes copy during interphase right before metaphase I of meiosis I so during Meiosis I the chromosomes are duplicated and not until metaphase II during meiosis II are the sister chromatids separated.
