What is a structure made of fibers that help to move chromosomes during mitosis?
What is a structure made of fibers that help to move chromosomes during mitosis?
The spindle is a structure made of microtubules, strong fibers that are part of the cell’s “skeleton.” Its job is to organize the chromosomes and move them around during mitosis. The spindle grows between the centrosomes as they move apart.
What are the names of the structures that move the chromosomes around during mitosis?
The movement of chromosomes is facilitated by a structure called the mitotic spindle, which consists of microtubules and associated proteins. Spindles extend from centrioles on each of the two sides (or poles) of the cell, attach to the chromosomes and align them, and pull the sister chromatids apart.
What are the last 2 chromosomes called?
The 22 autosomes are numbered by size. The other two chromosomes, X and Y, are the sex chromosomes. This picture of the human chromosomes lined up in pairs is called a karyotype.
How many DNA is in a chromosome?
There are 22 homologous pairs and two sex chromosomes (the X and Y chromosomes). One chromosome in each pair is inherited from one’s mother and one from one’s father. Each chromosome is a single molecule of DNA.
What is the main function of chromatin?
Chromatin is the material that makes up a chromosome that consists of DNA and protein. The major proteins in chromatin are proteins called histones. They act as packaging elements for the DNA. The reason that chromatin is important is that it’s a pretty good packing trick to get all the DNA inside a cell.
Do all human cells have chromosomes?
Some insects, for instance, only have one or two chromosomes. Every cell in the human body contains 23 pairs of such chromosomes; our diploid number is therefore 46, our ‘haploid’ number 23. Of the 23 pairs, 22 are known as autosomes. The 23rd pair is made up of the sex chromosomes, called the ‘X’ and ‘Y’ chromosome.
What is the Colour of DNA?
Figure 2: The four nitrogenous bases that compose DNA nucleotides are shown in bright colors: adenine (A, green), thymine (T, red), cytosine (C, orange), and guanine (G, blue).
Why Isopropanol is used in DNA extraction?
Since DNA is insoluble in ethanol and isopropanol, the addition of alcohol, followed by centrifugation, will cause the DNA proteins to come out of the solution. In addition, isopropanol is often used for precipitating DNA from large volumes as less alcohol is used (see protocols below).
Does DNA have 6 carbon sugars?
The sugar is deoxyribose in DNA and ribose in RNA. The purines have a double ring structure with a six-membered ring fused to a five-membered ring. Pyrimidines are smaller in size; they have a single six-membered ring structure. The sugar is deoxyribose in DNA and ribose in RNA.
Which sugars are Pentoses?
The pentoses, ribose, deoxyribose, and ribitol are also monosaccharides but are not thought of as major sources of dietary energy. They are called “pentoses” because, unlike glucose, fructose, and galactose, they are comprised of a five-carbon backbone rather than a six-carbon backbone.