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Sister chromatids of a metaphase chromosome animation

By: HWC, Views: 4711

At metaphase, the chromosomes are duplicated and are at their most condensed. In each chromosome. two identical sister chromatids are held together at a constricted region called the centromere. When a chromosome is condensed, interactions among chromosomal proteins keep loops of DNA tightly ...

Chromosome structural organization/ Mechanisms for chromosome movement Animation

By: HWC, Views: 2792

How the chromosome is organized. At metaphase, the chromosomes are duplicated and are at their most condensed. In each chromosome, two identical sister chromatids are held together at a constricted region called the centromere. When a chromosome is condensed, interactions among chromosomal ...

Amniocentesis and CVS Animation

By: HWC, Views: 3583

Amniocentesis and chorionic villus sampling (CVS) are prenatal diagnostic tools. In amniocentesis, which can be performed as early as 14 weeks into the gestation period. A syringe needle is inserted through the abdominal and uterine walls to withdraw some amniotic fluid. The fluid contains...

Hierarchical Sequencing Method - Sequence Tagged Sites

By: HWC, Views: 5866

In the hierarchical sequencing method, researchers begin by collecting cells. In humans, each cell contains 23 pairs of chromo-somes. Here we specifically track the DNA from just one of the 23 pairs. Chromosomes have a series of unique DNA sequences, called sequence-tagged sites (STSs), that a...

SNP Polymorphysim Microarray Chip - How to Test a Person's DNA

By: HWC, Views: 5948

To test a person's DNA, a researcher first needs a source of tissue. Most of the cells in a blood sample are red blood cells, which lack nuclei, but there are also a number of white blood cells, which do contain nuclei and chromosomal DNA. If we could see a particular DNA sequence in these cel...

Role of complement proteins

By: HWC, Views: 6403

• Non-specific and specific defense mechanisms work through the functions of complement proteins. • As soon as pathogens penetrate the physical barrier of the skin, other resistance mechanisms begin. • Cells, such as macrophages, phagocytize pathogens. • These cells increase exposu...

Mechanisms for chromosome movement Animation

By: HWC, Views: 3640

At mitotic metaphase, the fully-formed spindle is composed of many microtubules that extend from the poles. Some of these, the kinetochore microtubules, are attached to the kinetochores of each chromosome. Kinetochores are located at the centromeres. At anaphase, sister chromatids separate and...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 6147

Proteins are long chains of amino acids linked together by peptide bonds. Together with the other three biological macromolecules—carbohydrates, lipids, and nucleic acids—proteins are the building blocks of cells. Proteins are the most complex and abundant biological macromolecules in cel...

HIV replication/ Replication cycle of HIV

By: HWC, Views: 3797

Replication cycle of HIV, one of the retroviruses. The HIV virus is surrounded by a lipid envelope with embedded proteins. A coat of viral proteins surrounds two strands of RNA and the enzymes used during replication. The virus attaches to and enters the host cell. Viral reverse trans...