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Chromosomes
Chromosomes contain the genetic material DNA
1,309 Questions
How many chromosome in the nucleus?
46 total in somatic cells.
23 homologous pairs (chromosomes that carry the same genes). This pairing is why Mendelian inheritance works as it does.
Not all human cells have nuclei/genetic material. Red blood cells for example. And gametes (sex cells) only have 23 total, no homologous pairs.
Hope that helps!
The position is called locus (plural: loci).
Is dwarfism located on a particular chromosome?
Many inherited disorders in humans are controlled by a single gene. Achondroplasia is a form of dwarfism. About one out of 25,000 people has achondroplasia. The homozygous dominant genotype causes death of the embryo, and therefore only heterozygotes, individuals with a single copy of the defective allele, have this disorder. This also mean that a person with achondroplasia has a 50% chance of passing the condition on to any children. Achondroplasia is a recessive allele.
What might be the effect of inheriting more than the normal number of chromosomes in a human?
The implications of too many or too few chromosomes from the normal chromosomes are birth defects. With too many chromosomes a child could have Down Syndrome. With too few chromosomes a child could have Turner Syndrome.
What are the 26 different chromosomes?
Chromosomes are arranged in pairs and they are not yet named, but each of the pair is identified by numbers 1 to 22 (ie., twenty-two pairs of autosomes) and the 23rd pair by xx (in females) or xy (in males) to represent gonosomes (sex chromosomes).
What is the chromosome number at the end of meiosis 1?
Homologous chromosomes are separated at the end of meiosis 1. At the end of meiosis 2, the sister chromatids are separated.
At the end of meiosis 1: the daughter cells contain 2n number of chromosomes (where n is the haploid number for that particular organism)
At the end of meiosis 2: the daughter cells contain n number of chromosomes.
How many pairs of homologous chromosomes would be in an offspring?
Since a somatic cell (body cell) has 2n sets of chromosomes, and a gamete has n sets of chromosomes, then in this case: 18 = n, so 2n = 36. This organism has 36 chromosomes in its somatic cells.
How many chromosomes does a finches 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
Examine the chromosomes labeled x and y how does these two chromosomes compare?
up a homologous pair. They act similarly in their roles, but they are not homologous (the same). The X chromosome in humans is much longer than the Y chromosome and also contains many more genes.
How many gene is present in one chromosomes?
A given gene is present on exactly two chromosomes in a somatic cell.
What is a normal male karyotype?
The male karyotype has 46 chromosomes the same as the female karyotype:23 chromosomes are inherited from your father.
How many chromosomes human zygote possess?
46
23 from each parent...unless there is a mutation. Hi sorry to but in, but i was just wondering. If a human zygote contains 46 chromosomes and then total chromosomes they have is 46. Then if a mouse has 40 chromosomes would it's zygote be 40 as well? I have Biology homework and i was just wondering. Thanks!
What shape do chromosomes resemble?
If you mean as a whole, most chromosomes resemble the shape of the letter X. There may be a sex chromosome, and it may resemble the letter V in males of the species, though in that case, it is called a Y-Chromosome. During the anaphase of mitosis, they would be L-shaped.
If you mean in terms of the shape of the genetic material, then chromosomes have a double-helix shape.
When the chromosomes uncoil and disperse into a tangled of dense material?
DNA recieves a chemical signal from mRNA to unzip in whatever area is needed. Once it unzips it is copied by mRNA, since DNA is too big to leave the nucleus mRNA does. It goes and attaches to the ribosome where the DNA copy is read 3 letters at a time by tRNA which is a codon. For every codon an aminio acid is formed. They stick together to form a protein. This is called protein synthesis.
Chromosomes are strands of DNA wrapped around?
Chromosomes are not long strands of DNA. Genes are one form of long strands of DNA, specfied by meny amino acids, which are in turn specified by a codon, or three nucleotide bases. DNA actually coils or wraps around the chromosomes during certain stages of development.
What is the relationship between a chromosome and DNA?
Chromosomes are long strands of DNA that contain our genetic information. DNA is the molecule that makes up chromosomes, and it is organized into genes on the chromosomes. Each cell in our body contains a set of chromosomes that help determine our traits and characteristics.
What produces with half the normal number of chromosome?
the answer is MEIOSIS
meiosis produces 4 single cells with half member of the chromosomes
mitosis produces 2 cells with full member of the chromosomes
