Chromosomes have two functions what are they?
it is universally accepted that DNA is the genetic material and that in eukaryotes almost all the dna is present in chromosomes. thus the most important function of the chromosomes is to provide the genetic information for various cellular functions essential for survival ,growth, development ,reproductiuon etc of organisms. another important function of chromosomes is to protect the genetic material from being damaged during cell division .. the properties of chromosomes ensure a precise distribution of dna to the daughter nuclei during cell division. they ensure a regular and directional movement of the genetic material during cell division is an important function of chromosomes.,participation in regulation of gene action in eukaryotes is another function of the chromosomes. t elomeres ensures the stability of the c different chromosomes. and last but not least replication.
The strongest evolutionary theory for homosexuality is the so called “gay uncle hypothesis” that describes the evolutionary relation via kin selection, which is a form of group selection.If you are gay, you dont spend time/energy caring for your own young therefore:you can gather and contribute more resources to help your kin survive, such as giving more security or care for the young.you might compete less with others of the same sex, in your tribe.The former is more likely than the latter as the former explains both male/male and female/female homosexuality more easily, as women, traditionally were less competitive than men.Evidence for this theory is thathomosexuality is more likely amongst siblingshomosexuality is even more likely amongst twinsIn both these cases there is a high genetic factor, specifically there is more shared genes, which offers an explanatory mechanism for the expressions of the homosexual phenotype via a feedback mechanism. If the child bearing mother has a sense (potentially via hormones or epigenetics) that resources may be tight in her family or tribe it can make more sense to have a child that is devoted not to making children itself but to contributing resources to the siblings and their children.The reason this is the strongest theory is exactly because it is so closely linked to survival of your family members (your kin), which means passing on the majority of your genetics (through your kin instead of yourself), and to a less extent your tribe (your group).The other reason it is a strong hypothesis is that it offers a solution to the problem of why homosexuality has not been selected out over thousands of years, despite it being antithetical to reproduction.Darwin wrote about this in his Origin of Species where he explained that not only individuals compete for survival but bloodlines (kin groups) do.Kin and Group selection also offer a more natural explanation to altruism than individual competition.we are more altruistic to our kin, even beyond our upbringing to survivewe care for others who aren’t even our kin (especially in our tribe) despite them not contributing to passing on our genes, or our kin’s genes.These can be explained via culture, but primitive culture comes from natural behaviour of families and tribes.The natural bell curve variation that occurs in biology and sociology everywhere, explains the variable spectrum of the expression of the homosexual phenotype.
How many chromosomes should be in a healthy (human) cell?Short answer: there is no specific “number of chromosomes per healthy cell.” Depending on cell type, some have a multiple of 46 (plus mtDNA),some have 23 (ditto), and some have none at all.Ordered by number of chromosomes per cell, there are four cell categories (for details, follow the Wikipedia links), from high to low:Mature skeletal muscle cells(myocytes(syncytium),and one type of bone cell(osteoclasts)are multinucleated(i.e., more than one nucleus (46 chromosomes in each)). Additionally, each of their many mitochondriahave [math]\approx[/math] 100–10 000 circular chromosomes).Somatic cellsand primary germ cells(diploid)have 46 chromosomes — 23 maternal, 23 paternal (plus a number of mtDNA chromosomes).Gametes— egg cells(oocytes)and sperm cells (spermatozoons)— (haploid)have 23 chromosomes each (plus a number of mtDNA chromosomes).Mature red blood cells(erythrocytes)are anucleated,have neither nuclei nor mitochondria, i.e., they have no chromosomes.1. Skeletal Muscle Cell (myocyte, multiple diploid nuclei)) image snagged from humanbodyanatomy.copage Muscle Fiber Diagram:2. Somatic Cell Mitosis Phases (single diploid nucleus) image snagged from blog.nghsbio.orgarticle Mitosis = Somatic Cell Division:3. Gametes (sperm and egg cell, haploid nuclei) image snagged from www.dreamstime.compage Structure Of Human Gametes:4. Red Blood Cell (Erythrocyte, no nucleus) image snagged from rom slideplayer.com presentation Erythrocytes (Red Blood Cells), slide #5Thanks for asking, Lydia!
How do mutations occur?
In botany, or in biology in general? Mutations in biology happen usually when a virus injects its own genome - collected from other animals - into a victim's DNA via infecting other cells. These strains are then given a very, - and I mean VERY small chance to actually develop in the offspring of the host. That is usually how a 'mutation' develops.
Explain how non disjunction occurs and causes the genetic disorder, Down Syndrome?
For the best answers, search on this site https://shorturl.im/aylIO Down's Syndrome is one of the most common chromosomal disorders, occuring once in every 650 to 1,000 live births. It appears to occur with approximately equal frequency across ethnicities. Trisomy 21 infants occur less frequently among live births to mothers at age 20 (1/1600) than at age 35 (1/370). Most cases of Down syndrome result from trisomy 21, which means each cell in the body has three copies of chromosome 21 instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of Down syndrome. There is a significant genetic factor in autism. This is evident in twin studies. If one identical twin is autistic, the second one has an 80% chance of being somewhere on the autistic spectrum. If the child isn't autistic, she is likely to have some traits, just not enough to be classified autistic. Yet with faternal twins, if one twin is autistic, the 2nd twin is no more likely to be autistic than a sibling born 10 years later! (4%) They believe it isn't just one gene involved. It seems to be several genes that "collide" in one person to make then vunerable to autism. It's not 100% genes. If it was, then if one identical twin is autistic, the second one would ALWAYS be autistic.
What are chromosomes and how important are they in the body?
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 single DNA molecule), which contains many genes, regulatory elements and other intervening nucleotide sequences. Human cells have 23 pairs of large linear nuclear chromosomes, giving a total of 46 per cell. In addition to these, human cells have many hundreds of copies of the mitochondrial genome. Sequencing of the human genome has provided a great deal of information about each of the chromosomes. Number of genes is an estimate as it is in part based on gene predictions. Total chromosome length is an estimate as well, based on the estimated size of unsequenced heterochromatin regions. the chromosomes are important to decide whether u will be born as a boy or a girl. for ex: the man chromosom is XY and the woman is XX.