IN BACTERIA. Eukaryotes have two or more chromosomes‚ prokaryotes such as bacteria possess a single chromosome composed of double-stranded DNA in a loop. DNA is located in the nucleoid of the cell and is not associated with protein A plasmid is an extra-chromosomal DNA molecule separate from the chromosomal DNA which is capable of replicating independently of the chromosomal DNA. Plasmids usually occur naturally in bacteria. A chromosome is an organized structure of DNA and protein
Free DNA Bacteria Gene
most frequently occurring chromosomal abnormalities found in humans effecting people of all ages‚ races and economic levels. It is a chromosomal anomaly in cell development that results in a person being born with forty-seven chromosomes instead of the normal forty-six chromosomes. People with Down syndrome may have mild to severe learning disabilities and physical symptoms‚ which include a small skull‚ extra folds of skin under the eyes‚ and a protruding tongue. Roughly one out of every one thousand
Premium Down syndrome Chromosomes Cytogenetics
for #1: The arrangement of chromosomes in the diagram below is known as a karyotype. [pic] If the chromosomes of a female were arranged like the chromosomes of this male‚ which of the following would be true when the two karyotypes were compared? They would be identical (contain the same number and types of chromosomes) The karyotype of the male would contain one additional chromosome The karyotype of the female would contain one-half the number of chromosomes Karyotypes would appear different
Premium DNA Gene Chromosome
enough DNA to reach from here to the sun and back‚ more than 300 times. How is all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus? The haploid human genome contains approximately 3 billion base pairs of DNA packaged into 23 chromosomes. Of course‚ most cells in the body (except for female ova and male sperm) are diploid‚ with 23 pairs of chromosomes. That makes a total of 6 billion base pairs of DNA per cell. Because each base pair is around 0.34 nanometers long
Premium DNA Chromosome
often referred to as trisomy 21 because the cells for chromosome 21 are trisomic‚ meaning an individual with Down syndrome would have 47 chromosomes in all of their body cells. Down syndrome is a genetic disorder‚ there are 3 different types of chromosomal changes which can lead to Down syndrome: complete trisomy 21‚ whereby the nondisjunction occurs during the formation of the egg or sperm cells meaning all body cells will have 47 chromosomes. This is the most common causality of Down syndrome‚ accounting
Premium Pregnancy Childbirth Abortion
microscope as chromosomes. The nucleolus disappears. Centrioles begin moving to opposite ends of the cell and fibers extend from the centromeres. Some fibers cross the cell to form the mitotic spindle. METAPHASE = Spindle fibers align the chromosomes along the middle of the cell nucleus. This line is referred to as the metaphase plate. This organization helps to ensure that in the next phase‚ when the chromosomes are separated‚ each new nucleus will receive one copy of each chromosome. ANAPHASE
Premium Mitosis Cell cycle Chromosome
half the number of chromosomes as the parent cell. It enables organisms to reproduce sexually. Mitosis The production of two daughter cells that are identical to the parent cell. Parent cell=haploid‚ daughter cell=haploid. Parent cell=diploid‚ daughter cell=diploid. Chromosome A structure of nucleic acids and protein found in the nucleus of most living cells‚ which carry genetic information in the form of genes. Haploid The term used when a cell has only one set of chromosomes. Diploid The
Premium DNA Gene Genetics
facilitated diffusion 8. Particles too large to pass through protein channels in the cell membrane may enter the cell by: A. exocytosis B. selective transport C. endocytosis D. osmotic pressure 9. During mitosis: A. chromosomes are copied B. chromosomes move to opposite sides of the cell C. cytoplasm divides in half D. a new cell wall forms in the center of
Premium Cell Cell membrane Bacteria
Evolution‚ Genes & the Environment Variation is when you refer to genes; it means that there is a large variety of phenotypes‚ alleles and genotypes which can sometimes cause genetic variation. This results in different physical characteristics. Some examples of variations in humans are eye colour‚ hair colour and gender. Variations caused by the environment are the climate (tanned/pale skin) this is affected by the environment as the sun comes in contact with your skin and will darken it‚ the
Premium DNA Gene Genetics
organs of both sexes in a single individual’s body. Normal egg cells form after meiosis and are haploid‚ with half as many chromosomes as their mother’s body cells. Haploid individuals‚ however‚ are usually non-viable‚ and parthenogenetic offspring usually have the diploid chromosome number. Depending on the mechanism involved in restoring the diploid number of chromosomes‚ parthenogenetic offspring may have anywhere between all and half of the mother’s alleles. The offspring having all of the mother’s
Premium Reproduction Chromosome Meiosis