the nucleous Flashcards
(5 cards)
what is the nucleous too the cell
Anything that works, works best when it is controlled. For cells, “headquarters,” or the control center, is the nucleus (nucle = kernel). The genetic material, or deoxyribonucleic acid (DNA), is a blueprint that contains all the instructions needed for building the whole body; so, as you might expect, human DNA differs from frog DNA. More specifically, DNA has genes, which carry the instructions for building proteins. DNA is also absolutely necessary for cell reproduction. A cell that has lost or ejected its nucleus (for whatever reason) is destined to “self-destruct.”
Basically, this is saying that every cell has a nucleus, which acts as the headquarters or control center of the cell. Inside the nucleus is DNA, which contains the instructions for how to build proteins and even how to make new cells.
DNA holds genes, and these genes are like recipes for building everything the body needs. Since each species has different needs, human DNA is different from frog DNA, for example.
If a cell loses its nucleus, it loses its ability to function properly, and it will eventually self-destruct, because it can no longer follow or pass on the instructions needed for life.
does the nuclous always stay the same.
Although the nucleus is most often oval or spherical, its shape usually conforms to the shape of the cell. For example, if the cell is elongated, the nucleus is usually elongated as well. The nucleus has three recognizable regions or structures: the nuclear envelope, nucleolus, and chromatin.
The nuclear boundary is a double membrane barrier called the nuclear envelope, or nuclear membrane (Figure 3.3). Between the two membranes is a fluid-filled “moat,” or space. At various points, the two layers of the nuclear envelope fuse, generating openings called nuclear pores. Like other cellular membranes, the nuclear envelope allows some but not all substances to pass through it, but substances pass through it much more freely than elsewhere because of its relatively large pores. The nuclear membrane encloses a jellylike fluid called nucleoplasm (nu′kle-o-plazm″) in which other nuclear elements are suspended.
the nucleoplasm
It holds the nucleolus, chromatin/DNA, and other nuclear structures.
It provides a medium for molecules and ions to move around inside the nucleus.
It allows things like RNA and enzymes to float, move, and interact inside the nucleus.
nucleous how ribosomes are made
The nucleus contains one or more dark-staining round bodies called nucleoli (singular: nucleolus), which are the sites where ribosomes are made. These ribosomes then leave the nucleus and move into the cytoplasm, not the plasma membrane, where they become the sites of protein synthesis.
cheomatin
📘 What happens to DNA when the cell is not dividing?
DNA is loosely packed inside the nucleus.
It wraps around proteins called histones, forming a soft, stringy material called chromatin.
You can imagine this like a string of beads, where the string is DNA and the beads are histones.
🧬 What happens when the cell is getting ready to divide?
The chromatin coils up tightly to form chromosomes.
This makes it easier to move and organize the DNA during cell division.
Think of it like a stretched-out slinky (chromatin) that becomes short and thick (chromosome) when you let it go.
🔁 Why this matters:
Chromatin = relaxed form (cell is not dividing).
Chromosomes = compact form (cell is dividing).
This change helps the cell copy and separate DNA accurately when making new cells.
Would a diagram or visual comparison of chromatin vs. chromosomes help you see it more clearly?
