Cell Nucleus

* Cell Nucleus act as the brain of the cell
* It helps to control eating breathing like things
* Many cells have one nucleus and some have many
* Usually it has a Globular shape
* In animal Cells it is in the middle but in plant cells it is shifted to a side
* All cells do not have nucleus
* Only  eukaryotic  cells having it that is why it it is call as Nucleus cells
* Cell nucleus can divide in to two by its own.
* Nucleus division occur when Cell division occur let's discuss it under Cell division
* Parts of a nucleus

• Nucleus Membrane
• Nucleolus
• Chromatin

Nucleus membrane
 Nucleus membrane around the nucleus protects the nucleus from mechanical and other injuries.
2 parts of it
         inner membrane
         outer membrane


Chromatin
Chromatin contains Protein,RNA and DNA which controls the functions of the Cell.
Nucleolus  
RNA and protein makes the Nucleolus it is inside the nucleus
.
*Apart from above parts nucleus plasma fills whole nucleus.

 

Significant Differences Between Plant Cell & Animal Cell

Plant Cell	Animal Cell
Have Chloroplast Involve in photosynthesis Have Cell wall made with Cellulose One very large vacuole in the center Rectangular shape	Do not have Chloroplast Don't involve in photosynthesis No Cell wall Small vacuoles No shape

Plant Cell

Outer boundary is cell wall
Plant cell have a cell wall
Having Chloroplasts for photosynthesis
Eukaryotic cells
basic structure is same to animal cell

Consists with

Cell wall

Chloroplast

Endoplasmic Reticulum

Golgi

Nucleus

Ribosomes

Vacuole 

Animal Cell

Animal cells are typical Eucaryotic cells
Enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles
Animal cells do not have a Cell wall
Both plant and animal cells ranged between 1-100 micro meters
These cells cant see by unaided eye and we have to use compound microscope to observe animal cells

Above picture shows the structure of typical animal cell. But cell to cell above structure can be different and that is only the typical cell structure.

Now lets see what are the organelles we can see in these cells.

Plasma-membrane

Cell Plasma

Endoplasmic Reticulum

Golgi aparates

Lysosomes

Nucleus

Peroxisomes

Mitochondria

Ribosomes

After discussing about plant cell in my next blog post I will show you about each organelles later

Differences between Prokaryotic and Eucaryotic

Prokaryotic Cells
Small cells comparing to Eucaryotic cells
Always unicellular
No Nucleus
No any membrane-bound organelles ( Like mitochondria)
DNA is circular and do not combine with Histone
Ribosomes are small (70s)
No cytoskeleton
Cell division by binary fission
Reproduction is asexual

Eucaryotic Cells
Larger Cells comparing to prokaryotic cells
Often Multicellular
Always have Nucleus
DNA is combined with Histone
Ribosomes are large (80s)
There is a cytoskeleton
Cell division is by mitosis or meiosis

 

Kingdoms of Biology

When we consider living organisms there are several groups. Some animals have different characteristics. So according to the characteristics of living organisms they are categorize in to 5 Kingdoms
Monera
Protists
Fungi
Plantae
Animalia

Monera
Monera is single cell organisms. eg: Bacteria, Cynobacteria. Among all the living organisms bacteria are the most common living organism is Bacteria. Bacteria are also known as living fossils because they are present on earth more than 20000 years not facing to any differences.

Protists
This is another living organism type. Many of them are single cells. Some are moving and some are not moving.

Fungi
Motionless living organisms which absorb nutrients.

Plantae
Multi celled organisms. Green organisms. They use photosynthesis process to provide energy. Cell walls are created with cellulose

Animalia

Most complex living organisms on earth. Multi-cell organisms.Cant produce food using sunlight use organic matter as source for food.

What is chromosome?

In the nucleus of each cell, the DNA molecule is packaged in to threat- like structures called chromosome. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

Chromosomes are not visible in the cell nucleus not even under microscope when the cell is not dividing. However the DNA that makes up chromosomes become more tightly packed during cell division is then visible under microscope.