Chromosomes

AnaPhase1

A karyotype is a picture of all the chromosomes in a person's cells. A human has 46 chromosomes in all but sex cells.

Don't listen to that person if you want to know you shall know a shark has 82 chromosomes and I know because of school I am taking a test that tells me how many they have

In late anaphase and G1 of interphase, a chromosome is unreplicated and consists of a single DNA double helix.

A replicated chromosome contains two identical DNA double helices.

Meiotic nondisjunction. In meiosis I or II, chromosome pair 21 fail to separate correctly, leaving one gamete with an extra chromosome 21.

The chromosomes condense in prophase of mitosis. https://en.wikipedia.org/wiki/Mitosis#/media/File:Animal_cell_cycle-en.svg

22

23 Pairs

The cellular component that helps pull apart the chromosome in mitosis and meiosis are the spindle fibers. These spindle fibers are made of micro-tubules.

Gametes are reproductive cells produced by a type of cell division called meiosis. They contain only one set of chromosomes and are said to be haploid.

The sex chromosomes will usually be in the last place on the karyotype (typically the bottom right corner). If/when the karyotype is numbered, the sex chromosomes should be numbered as the 23rd pair.

Autosomal genes are the genes that make up your average chromosomes that contain the basic body features. Such as bone, skin, eyes, and etc. These give a person the basic structure and basic of the development. The sex genes are either X or Y which determine if you are a male or female.

i like men

prophase

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).

Information is lost.

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.

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.

X chromosome

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).

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.

Cell. More specifically, in the nucleus of the cell.

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.