chromosome

Examples of chromosome in the following topics:

• Chromosomes and Genes

  • Chromosomes also contain genes, most of which are made up of DNA and RNA.
  • Human chromosomes are divided into two types—autosomes and sex chromosomes.
  • Common abnormalities include Down syndrome (caused by an extra chromosome #21), Klinefelter syndrome (caused by an extra X chromosome), and Turner syndrome (caused by a missing X chromosome).
  • Chromosomal and genetic manipulation are controversial topics.
  • Chromosomes are made up of a variety of gene sequences.

• The Role of Genes in Prenatal Development

  • Every person is made up of cells, each of which contains chromosomes.
  • A human being has a total of 23 pairs of chromosomes.
  • The developing zygote gets half of its chromosomes from one parent and half from the other parent.
  • The first 22 pairs of chromosomes are known as autosomes and determine things such as eye and hair color.
  • The last pair, known as the sex chromosomes, determine a person's biological sex: females have two X chromosomes, while males have an X and a Y chromosome.

• Sex and Physiology

  • Sex is biologically determined based on chromosomes, hormones, gonads, internal reproductive anatomy, and external genitalia.
  • Intersex, in humans and other animals, is a variation in sex characteristics (including chromosomes, gonads, or genitals) that does not allow an individual to be distinctly identified as male or female.
  • Such variation may involve genital ambiguity and/or combinations of chromosomes other than XY (typically found in males) and XX (typically found in females).
  • In addition to the most common XX and XY chromosomal sexes, there are several other possible combinations commonly known as intersex, such as Turner syndrome (XO), Triple X syndrome (XXX), Klinefelter syndrome (XXY), de la Chapelle syndrome (XX male), and Swyer syndrome (XY female).

• Intellectual Disabilities

  • Down syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of a full or partial third copy of chromosome 21.
  • Down syndrome is one of the most common chromosome abnormalities in humans, occurring in about one per 1000 babies born each year.
  • Down Syndrome is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.

• Genetic Basis of Intelligence and Learning

  • While experts believe the genetic cause for the syndrome is a lack of genes in the 21st chromosome, the gene(s) responsible for the cognitive symptoms have yet to be discovered.

• Defining Sex, Gender, and Sexuality

  • In humans, the biological sex of a child is determined at birth based on several factors, including chromosomes, gonads, hormones, internal reproductive anatomy, and genitalia.
  • However, anywhere from 1.0 to 1.7% of children are born intersex, having a variation in sex characteristics (including chromosomes, gonads, or genitals) that do not allow them to be distinctly identified as male or female.

• Genetic and Environmental Impacts on Intelligence

  • While experts believe the genetic cause for Down syndrome is a lack of genes in the 21st chromosome, the gene(s) responsible for the cognitive symptoms have yet to be discovered.