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Why does DNA need to coil up into chromosomes?
DNA is tightly packed up to fit in the nucleus of every cell. As shown in the animation, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. Condensing DNA into chromosomes prevents DNA tangling and damage during cell division.
Why do chromosomes coil up during mitosis?
Why do chromosomes coil during mitosis? E) The chromosomes are “reeled in” by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles.
What must DNA do before it divides?
Before a cell divides, the strands of DNA in the nucleus must be copied, checked for errors and then packaged into neat finger-like structures. The cell division stages encompass a complicated process that involves many changes inside the cell.
Why is it important that DNA is replicated before the cell divides?
Cells must replicate their DNA before they can divide. This ensures that each daughter cell gets a copy of the genome, and therefore, successful inheritance of genetic traits. DNA replication is an essential process and the basic mechanism is conserved in all organisms.
What causes DNA to wrap around histones?
The tight wrapping of DNA around histones is to a large degree a result of electrostatic attraction between the positively charged histones and negatively charged phosphate backbone of DNA. Histones may be chemically modified through the action of enzymes to regulate gene transcription.
Why is it important for DNA to condense into chromosomes quizlet?
Cells need to be able to organize their genetic material so that it can be sorted easily and fit into the nucleus for division. By condensing DNA into chromosomes, cells can align each chromosome (or during meiosis, each tetrad), along the metaphase plate.
What would happen if DNA was not replicated?
Without the copying of the DNA life would not continue as existing organisms would not be able to reproduce and replace themselves. Life is dependent on the information stored on the DNA. Without replication of the DNA the information would not be passed on and life would cease to exist.
Where does DNA coil up before it divides?
In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. Hereof, why must DNA coil up before it divides? Why DNA must coil up into chromosome structures before it divides?
What happens to the chromosomes during cytokinesis?
During cytokinesis the chromosomes unwind and become a pile of very long, thin, thread-like DNA and the cell goes back to looking “normal” until mitosis begins again. Brainstorm with your group ideas why the DNA must coil up into chromosome structures before it divides.
What makes up the DNA in each chromosome?
DNA in each chromosome is wrapped around proteins called histones. The DNA/histone beads further coil up like a spring/slinky. These are bent by attaching them scaffolds made of proteins. In interphase, which phase does the cell spend the most time in? Least time? Which phase has the most organelles? T/F: Every cell divides at a different rate.
Why do cells need to copy the chromosomes?
The cell must copy the chromosome material so there is enough to make two new cells with the correct chromosome number. ll. Refer to Model 1. The chromosomes that are shaped like “X” (made of ÑK) sister chromatids) have double the amount of DNA than the chromosomes that are shaped like “I.”