What is a Chromosome?

What is a chromosome?

To solve problems that explain and predict traits and variations, we first have to understand cells. All living organisms are composed of cells. Cells work like little factories doing all the jobs inside your body that are needed to keep your body functioning. Your body is made up of many different kinds of cells such as skin cells, muscle cells, and nerve cells. Some cells look like squashed bricks, some look like doughnuts, and many have irregular shapes. However, every cell, no matter what its job, has the same basic parts.

All human cells have an outer border that is the boundary of the cell called the cell membrane. A liquid material called cytoplasm is inside the cell membrane, and there is a large structure suspended in the cytoplasm called the nucleus. The nucleus is the part of a cell that contains the genetic information. The nucleus is surrounded by a nuclear membrane that, like the cell membrane, makes a boundary around the nucleus.

Now let's explore chromosomes.  Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid, or "DNA". Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique. The term chromosome comes from the Greek words for color (chroma) and body (soma). Scientists gave this name to chromosomes because they are cell structures, or bodies, that are strongly stained by some colorful dyes used in research.

So what do chromosomes actually do?

The unique structure of chromosomes keeps DNA tightly wrapped around spool-like proteins, called histones. Without such packaging, DNA molecules would be too long to fit inside cells. For an organism to grow and function properly, cells must constantly divide to produce new cells to replace old, worn-out cells. During cell division, it is essential that DNA remains intact and evenly distributed among cells. Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions.

[murd_bird]

im 15 but ive been watching these types of videos because i never, ever paid attention in school and sadly it has affected me

[hyuckieverse]

*This is what happens when you didn’t listen to your science teacher*

[TonyTigerTonyTiger]

Several other small issues with the video.

2) The nucleus is surrounded by a nuclear envelope, which consists of 2 membranes.

3) Not all human cells have a nucleus (mature red blood cells do not, and neither do cells of the eye lens, for example).

4) The liquid part inside the plasma membrane but outside of the nucleus is not the cytoplasm, but the cytosol. The cytoplasm includes both the cytosol and everything (mitochondria, ribosomes, proteins, etc.) suspended in it.

[_claymore]

Filthy frank should have been in this video

[guitarttimman]

The center of the Chromosome is called the centromere. 
Each chromosome has alleles. Some are dominant and others are recessive. Some recessive genes are defective and cause hereditary traits that lead to defective phenotype. An example can be seen in the recessive allele for hypophosphatemia. This is displayed in the gametes (not the autosomes). If the mother is a carrier of it, she will have one recessive allele on an X chromosome. If the Father imparts a Y chromosome to the mother's recessive X allele of the oocyte, then the BOY child will inherit the disorder. But, if the Father impart an X chromosome to the mother recessive X allele, then the baby GIRL will be a carrier as well. interesting. I guess I know a little about it.

[MsGuernseyGirl]

Great video but I found the background music intrusive and irritating.

[icantbiteice]

How did i go from the meme york times to this

[MundaneMuser]

Easy to understand. Nice music by the way.

[carolinaalcantara]

I wish your video was longer. I actually enjoyed your explanations - there are some really bad videos on chromosomes on here that don't quite explain it as clearly like you do. I just wish you gave us more information! Thank you!

[MooMooMath]

My students enjoyed this video. I shared it on Pinterest

[ashleybryant]

Ashley Bryant GOL 106 V1. I learned that the Nucleus contains the genetic information of a creature and it is located in the center of a cell.

[DannyKechik_the_dizzydaisy]

The intro music is cooler than the ice on my wrist.

[TonyTigerTonyTiger]

Human cells don't have chloroplasts.

PS: It is basically implied by the video that our cells do: around @0:25 the video speaks to us listeners and refers to "our bodies", whicle showing a diagram of a cell with a chloroplast in it.

[iliketurtles]

The structure of a cell looks a hell of a lot like the structure of this Earth. Interesting.

[illyGalSloth]

I have two possibly stupid questions. Can a cell copy itself more than once? As it only has two copies of DNA inside it, so it can make another exact replica of itself, which leads to my second question. When the cell divides, does its copy also get two copies of the original DNA? (I have only recently started this topic at school, so I don't really know much about chromosomes)

[Itzak]

i think i just lost a couple chromosomes

[Globe_Trotter]

The Shortest and the best explanation ✔

[nusratnipu]

Our teacher show us it in multimedia class.

[dr.abdulhaseeb]

I just thank u red orbit for providing a lot of ample information
thankx for helping me in my final of to u please keep making these type of videos for physics and chem too

[macalipaymykarica]

i just wanna download this vid in our laptop but i can't download it cause there is no download put in here :(