Basics only
Ribosome’s are a cell structure that makes protein (seat of protein synthesis).
• Ribosomes are often referred as PROTEIN FACTORY of the cell.
• Protein is needed for many cell functions such as repairing damage or directing
chemical processes.
• The ribosome is a complex molecule made of ribosomal RNA molecules and
proteins that form a factory for protein synthesis in cells.
Basics only
Ribosome’s are a cell structure that makes protein (seat of protein synthesis).
• Ribosomes are often referred as PROTEIN FACTORY of the cell.
• Protein is needed for many cell functions such as repairing damage or directing
chemical processes.
• The ribosome is a complex molecule made of ribosomal RNA molecules and
proteins that form a factory for protein synthesis in cells.
Nucleus: Structure and function
nuclear membrane
nuclear lamins
Nuclear pore complexe
nuclear matrix, composition and its role
cajal bodies
SFCs
nuclear speckles
PML bodies
Nucleolus
Rajeshwari pharm D .....chromatin: chromatin is a mass of genetic material......Types of chromatin
1.EUCHROMATIN
2.HETEROCHROMATIN
FUNCTIONS OF CHROMATIN: to compress the dna into compact form....flow of genetic information.
Structure and functions of endoplasmic reticulumICHHA PURAK
The presentation consists of 57 slides,describes following heads
• DISCOVERY
• INTRODUCTION
• BIOGENESIS OF ER
• ISOLATION OF MICROSOMES FROM E R
• STRUCTURE
• COMPONENTS OF ER
CISTERNAE
VESICLES
TUBULES
• MAIN FUNCTION OF ER
• TYPES OF ENDOPLASMIC RETICULUM
• SMOOTH ENDOPLASMIC RETICULUM (SER)
• FUNCTIONS OF SER
• ROUGH ENDOPLASMIC RETICULUM (RER)
• FUNCTIONS OF RER
• SUMMARY
• REFERENCES
• QUESTIONS
Cytoskeleton - microtubules ,microfilaments and intermediate filamentsBIOTECH SIMPLIFIED
The cytoskeleton is a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement. There is no single cytoskeletal component. Rather, several different components work together to form the cytoskeleton.
DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
DNA packaging is crucial because it makes sure that those excessive DNA are able to fit nicely in a cell that is many times smaller.
The DNA in bacterial cells are either circular or linear. To accommodate the size of bacterial cell, supercoiled DNA are folded into loops with each loop resembles shape of bead-like packets containing small basic proteins that is analogous to histone found in Eukaryotes.
Nucleus” is a Latin word meaning Kernel
It is the “CONTROL CENTER” of the cell
Average diameter of nucleus is 6um, which occupies around 10% of cell volume
Nuclear Envelope
Nuclear Pores and complex
Nuclear lamina
Chromosomes & Chromatin
Nucleolus
Nucleoplasm
The Greek words "Chroma," which means colour, and "Soma," which means body, were combined to create the English word "chromosome." They are distinct cell organelles made of chromatin, the most significant and durable component of the cell nucleus. They have the ability to reproduce themselves. They are important for differentiation, heredity, mutation, and evolution and regulate the structure and metabolism of cells.
General History of Chromosomes
Nuclear filaments were found by W. Hofmeister in the Tradescantia pollen mother cells' nuclei in 1848. W. Flemming conducted the first precise chromosome count in a cell's nucleus in 1882. W. Flemming, Evan Beneden, and E. Strasburger showed in 1884 that the chromosomes double in number during mitosis through longitudinal division. Beneden discovered that each species had a fixed number of chromosomes in 1887. W. Waldeyer first used the term "chromosomes" for the nuclear filaments in 1888. The role of chromosomes in heredity was first proposed by W.S. Sutton and T. Boveri in 1902, and it was later supported by Morgan in 1933.
In viruses, prokaryotes, and eukaryotes, chromosome structures differ.
1. Viral chromosome- In viruses, each chromosome contains a single nucleic acid molecule (DNA or RNA), which is encased in a protein coat known as the capsid. It could be circular or linear. The term "DNA virus" refers to viruses with DNA as their genetic material, while the term "RNA virus" refers to viruses with RNA as their genetic material. The viral chromosome contains a small amount of genetic material that primarily regulates the generation of additional identical virus particles in the host cell. In RNA viruses, the RNA frequently instructs the host's reverse transcription process to create DNA that is complementary to itself.
The DNA then uses the RNA to create new viral particles by transcribing it. Retroviruses are one type of ribovirus. A retrovirus is what causes AIDS.
2. Prokaryotic chromosomes- A single circular two-stranded DNA molecule found on prokaryotic chromosomes, such as those found in bacteria, is not encased by any membrane. It is in direct contact with the cytoplasm and is protein-free.
Some RNA that seems to form a core encases the bacterial chromosome in the nucleoid. At some point, it is anchored permanently to the plasma membrane. Most bacterial cells also contain some extra-chromosomal DNA molecules that are double stranded and circular but much smaller in size than the main chromosome. Plasmids are the name for them.
The plasmid can appear on its own in the cytoplasm of cells or it can also be discovered in associated with the main chromosomal DNA and is known as an episome.
3. Eukaryotic chromosomes- The nucleus and some other organelles, like mitochondria and plastids, contain the eukaryotic chromosomes. Nuclear and extra nuclear chromosomes are the names given to these chromosomes, respectively.
Double-stranded, linear, long DNA molecules make up nuclear chromosomes. They are
Nucleus: Structure and function
nuclear membrane
nuclear lamins
Nuclear pore complexe
nuclear matrix, composition and its role
cajal bodies
SFCs
nuclear speckles
PML bodies
Nucleolus
Rajeshwari pharm D .....chromatin: chromatin is a mass of genetic material......Types of chromatin
1.EUCHROMATIN
2.HETEROCHROMATIN
FUNCTIONS OF CHROMATIN: to compress the dna into compact form....flow of genetic information.
Structure and functions of endoplasmic reticulumICHHA PURAK
The presentation consists of 57 slides,describes following heads
• DISCOVERY
• INTRODUCTION
• BIOGENESIS OF ER
• ISOLATION OF MICROSOMES FROM E R
• STRUCTURE
• COMPONENTS OF ER
CISTERNAE
VESICLES
TUBULES
• MAIN FUNCTION OF ER
• TYPES OF ENDOPLASMIC RETICULUM
• SMOOTH ENDOPLASMIC RETICULUM (SER)
• FUNCTIONS OF SER
• ROUGH ENDOPLASMIC RETICULUM (RER)
• FUNCTIONS OF RER
• SUMMARY
• REFERENCES
• QUESTIONS
Cytoskeleton - microtubules ,microfilaments and intermediate filamentsBIOTECH SIMPLIFIED
The cytoskeleton is a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement. There is no single cytoskeletal component. Rather, several different components work together to form the cytoskeleton.
DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
DNA packaging is crucial because it makes sure that those excessive DNA are able to fit nicely in a cell that is many times smaller.
The DNA in bacterial cells are either circular or linear. To accommodate the size of bacterial cell, supercoiled DNA are folded into loops with each loop resembles shape of bead-like packets containing small basic proteins that is analogous to histone found in Eukaryotes.
Nucleus” is a Latin word meaning Kernel
It is the “CONTROL CENTER” of the cell
Average diameter of nucleus is 6um, which occupies around 10% of cell volume
Nuclear Envelope
Nuclear Pores and complex
Nuclear lamina
Chromosomes & Chromatin
Nucleolus
Nucleoplasm
The Greek words "Chroma," which means colour, and "Soma," which means body, were combined to create the English word "chromosome." They are distinct cell organelles made of chromatin, the most significant and durable component of the cell nucleus. They have the ability to reproduce themselves. They are important for differentiation, heredity, mutation, and evolution and regulate the structure and metabolism of cells.
General History of Chromosomes
Nuclear filaments were found by W. Hofmeister in the Tradescantia pollen mother cells' nuclei in 1848. W. Flemming conducted the first precise chromosome count in a cell's nucleus in 1882. W. Flemming, Evan Beneden, and E. Strasburger showed in 1884 that the chromosomes double in number during mitosis through longitudinal division. Beneden discovered that each species had a fixed number of chromosomes in 1887. W. Waldeyer first used the term "chromosomes" for the nuclear filaments in 1888. The role of chromosomes in heredity was first proposed by W.S. Sutton and T. Boveri in 1902, and it was later supported by Morgan in 1933.
In viruses, prokaryotes, and eukaryotes, chromosome structures differ.
1. Viral chromosome- In viruses, each chromosome contains a single nucleic acid molecule (DNA or RNA), which is encased in a protein coat known as the capsid. It could be circular or linear. The term "DNA virus" refers to viruses with DNA as their genetic material, while the term "RNA virus" refers to viruses with RNA as their genetic material. The viral chromosome contains a small amount of genetic material that primarily regulates the generation of additional identical virus particles in the host cell. In RNA viruses, the RNA frequently instructs the host's reverse transcription process to create DNA that is complementary to itself.
The DNA then uses the RNA to create new viral particles by transcribing it. Retroviruses are one type of ribovirus. A retrovirus is what causes AIDS.
2. Prokaryotic chromosomes- A single circular two-stranded DNA molecule found on prokaryotic chromosomes, such as those found in bacteria, is not encased by any membrane. It is in direct contact with the cytoplasm and is protein-free.
Some RNA that seems to form a core encases the bacterial chromosome in the nucleoid. At some point, it is anchored permanently to the plasma membrane. Most bacterial cells also contain some extra-chromosomal DNA molecules that are double stranded and circular but much smaller in size than the main chromosome. Plasmids are the name for them.
The plasmid can appear on its own in the cytoplasm of cells or it can also be discovered in associated with the main chromosomal DNA and is known as an episome.
3. Eukaryotic chromosomes- The nucleus and some other organelles, like mitochondria and plastids, contain the eukaryotic chromosomes. Nuclear and extra nuclear chromosomes are the names given to these chromosomes, respectively.
Double-stranded, linear, long DNA molecules make up nuclear chromosomes. They are
Types of chromosomes, basic structural features, chromosomal numbers, chromosomal banding, molecular organization of eukaryotic chromosome, MARS/SARS. Heterochromatin, euchromatin structures; structural organization of centromeric region, components and structure of Kinetochore, difference between mitotic kinetochores and meiotic kinetochores; structural organization of telomeres, proteins involved in heterochromatization of telomeric regions. Structural organization and molecular biology of salivary gland and Lampbrush chromosomes, importance of their study at specific stages of development.
Chromosome structure and packaging of dnaDIPTI NARWAL
Chromosome structure : classification based upon centromere position, autosomes and allosomes
Morphology of chromosome: chromatids, chromomeres, telomeres, sister chromatids
packaging of DNA: nucleosome model
functions of Chromosomes
CHROMOSOMES - Dr. P. Saranraj, Assistant Professor, Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Vellore District, Tamil Nadu, India.
Cell DivisionCell Division in ProkaryotesBinary FissionDefMaximaSheffield592
Cell Division
Cell Division in Prokaryotes
Binary Fission
Definition
Bacterial cells divide by a method of asexual reproduction known as binary fission. Fission means splitting. So in the process the genetic material is replicated, the cell grows larger and then splits into two.
Genetic Material of the Bacterial Cell
The genetic information of a bacterial cell exists as a single, circular, double-stranded DNA molecule. Bacterial cells are prokaryotic cells; they lack a nucleus. The DNA of the bacterial cell is not surrounded by and enclosed within a nuclear membrane. It lies free within the protoplasm of the bacterial cell. Although the bacterial cell lacks a nucleus, the area of the cell protoplasm where the nucleus is found is called the nucleoid.
Prior to the Division of the Cell the DNA must be Doubled
Prior to the division of the bacterial cell, the DNA must be replicated, producing two copies that can be equally distributed to each of the two daughter cells. Replication of the DNA at a specific site on the DNA molecule called the origin of replication. The replication enzymes copy the DNA of both strands, moving around the circular DNA in both directions simultaneously until a specific site of termination is reached. When these enzymes have proceeded all the way around the circle of DNA, the cell possesses two copies of the genome. These “daughter” genomes are attached side-by-side to the plasma membrane.
Elongation of the Cell and Segregation of DNA to Opposite Ends of the Cell
As the DNA replicates, the cell elongates. The two circular molecules of DNA now separate and move apart toward opposite ends of the cell.
Fission of the Cell into two Daughter Cells
After the DNA molecules have been segregated to opposite ends of the cell, the bacterial cell will divide to form two daughter cells. Then a group of proteins that will operate together to separate the cell into two assemble at the site of separation. A key component of this group of division machinery proteins is the protein FtsZ. FtsZ proteins begin the separation process by forming a ring in the middle of the cell. Other components of the division apparatus then join the FtsZ ring, forming new plasma membrane that separates the cytoplasm into the two cells. This is followed by the formation of cell wall material in the separation zones. The result of the process of binary fission is two cells, each with its own circular, double stranded, DNA molecule.
The cell will now begin to split into two cells by a process called septation. This occurs as a septum forms in the middle of the cell. A protein called FtsZ forms a ring in the middle of the cell. As this process proceeds, the cell lays down new plasma membrane and cell wall materials in the zone between the attachment sites of the two daughter genomes. A new plasma membrane grows between the genomes; eventually, it reaches all the way into the center of the cell, dividing it in two. B ...
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
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2. Introduction
Chromosomes are thread-like structures present in the nucleus, which carries genetic information from
one generation to another.
They play a vital role in cell division, heredity, variation, mutation, repair and regeneration.
In Eukaryotic cells, genetic material is present in the nucleus in chromosomes, which is made up of
highly organized DNA molecules with histone proteins supporting its structure.
The term chromosome comes from the Greek words for (chroma) color and body (soma) Chromosome
means ‘colored body’ that refers to its staining ability by certain dyes.
Karl Nagli in 1842, first observed the rod-like structure present in the nucleus of the plant cell.
W. Waldeyer in 1888 coined the term ‘chromosome’.
Walter Sutton and Theodor Boveri in 1902 suggested that chromosomes are the physical carrier of
genes in the eukaryotic cells.
Chromosomes are not visible during interphase under light microscope. During other stages of cell
division, they are visible, but are more clearly visible during mitotic metaphase
Chromosomes have property of self-duplication, segregation and mutation.
The number of chromosome in a gamete is called Genomes.(in human23)
3. Chemical Composition
Chromosomes vary in shape, size and number in different species of plants and animals.
Shapes -Chromosomes have generally three different shapes, viz., rod shape, J shape and V shape. These shapes are
observed when the centromere occupies terminal, sub-terminal and median (middle) position on the chromosomes.
Size-Chromosome size is measured with the help of micrometer at mitotic metaphase. It is measured in two ways, viz.,
in length and in diameter. Plants usually have longer chromosomes than animals. The maximum length of
chromosome is observed during interphase and minimum during anaphase. Thus chromosome size varies from species
to species from 0.5-30 µ, Giant chromosomes have length up to 300 µ and diameter from 0.2-3µ.
Number-
Nematode -species contains only 2 chromosomes in a cell.
Protozoan -species contains as much as 1600 chromosomes in the cell.
Plant and animal species -contain 8 to 50 number of chromosomes in its somatic cell.
A human cell contains total 23 pair of chromosomes (2n, total 23×2=46), of which 22 are autosomes and 1 sex
chromosome.
4. Types of Chromosomes
1. Chromosomes are divided into two parts (p and q arms) with a constriction point called a centromere in the middle.
2. Centromere divides the chromosome into two parts, the shorter arm is known as ‘p’ arm and the longer arm is
known as ‘q’ arm.
(A)Based on the positions of centromeres -
Metacentric – centromere is in middle, meaning p and q arms are of comparable length (e.g. chromosomes 1, 3, 16, 19,
20)
Sub metacentric – centromere off-center, leading to shorter p arm relative to q arm (e.g. chromosomes 2, 4 – 12, 17, 18,
X)
Acrocentric – centromere severely off-set from center, leading to much shorter p arm (e.g. chromosomes 13 – 15, 21, 22,
Y)
Telocentric – centromere found at end of chromosome, meaning no p arm exists (chromosome not found in humans)
5. (B) Based on the number of centromeres -
1. Monocentric - only one centromere present.
2. Dicentric- only two centromere present.
3. Polycentric -. More than two centromere present.
4. Acentric- Without centromere.
6. Types of Special Chromosome
1. Polytene chromosome/ Giant Chromosomes
1. Balbiani first discovered in 1881.
2. Painter, Heitz and Bauer, rediscovered them in the salivary gland of
Drosophila and recognized them as a chromosome.
3. Also known as Salivary gland chromosome.
4. These are called polytene by Kollar due to the presence of many
chromonemata in them.
5. These are present in some cells of the larvae of Dipteran insects.
6. These are very large due to the presence of high DNA content.
7. The polytene chromosome of Drosophila’s salivary gland has 1000 DNA
molecules Chironomus has 1600 DNA molecules in its each polytene
chromosome.
8. There is a series of alternating dark and clear bands called interband.
9. Chromosome puffs or Balbiani rings are present, which are the swelling
of bands due to DNA unfolding into open loops. These are the region of
the intense transcription or mRNA formation.
7. 2. Lampbrush chromosome
1. First discovered in the oocytes of amphibian, fishes and insects.
2. The name is given due to its resemblance with a brush that is used for
cleaning lamp, glass chimneys, etc.
3. They occur at the diplotene stage of oocytes in vertebrates and
invertebrates.
4. Lampbrush chromosomes are also found in the spermatocytes of
many animals and also found in the giant nucleus of an
algae Acetabularia.
5. They are present as a bivalent with 4 chromatids
6. Chromosomal axis is formed from highly condensed chromatin
and lateral loops extend from the row of chromomeres.
7. Lateral loops of DNA are always symmetrical and formed due to
intense RNA synthesis
8. In the oocytes of salamander, there are 10,000 loops present per
haploid set of chromosomes.
9. The centromere doesn’t bear any loops.
8. Structure of Chromosome
Each cell has a pair of each kind of chromosome known as a homologous chromosome.
Chromosomes are made up of chromatin, which contains a single molecule of DNA and associated
proteins. Each chromosome contains hundreds and thousands of genes that can precisely code for
several proteins in the cell. Structure of a chromosome can be best seen during cell division.
1. Chromonema-
Under light microscope, thread like coiled structures are found in the chromosomes and chromatids
which are called chromonema. Two chromatids which are joint at a place called centromere.
Chromonema are sub chromatid in nature.
2. Pellicle /Matrix-
A mass of acromatic material in which chromonemata are embedded is called matrix. Matrix is
enclosed in a sheath which is known as pellicle. Both matrix and pellicle are non-genetic materials.
3. Chromatid-
1. Each chromosome has two symmetrical structures called chromatids or sister chromatids which is
visible in mitotic metaphase.
2. Each chromatid contains a single DNA molecule.
3. At the anaphase of mitotic cell division, sister chromatids separate and migrate to opposite poles.
9. 4. Centromere and kinetochore-
1. Sister chromatids are joined by the centromere.
2. Spindle fibres during cell division are attached at the centromere.
3. The number and position of the centromere differs in different chromosomes.
4. The centromere is called primary constriction.
5. Centromere divides the chromosome into two parts, the shorter arm is known as ‘p’
arm and the longer arm is known as ‘q’ arm.
6. The centromere contains a disc-shaped kinetochore, which has specific DNA
sequence with special proteins bound to them.
7. The kinetochore provides the center for polymerization of tubulin proteins and
assembly of microtubules.
8. This is also called kinetochore.
.
10. 5. Secondary constriction and nucleolar organizers-Other than centromere, chromosomes
possess secondary constrictions. Secondary constrictions can be identified from centromere at
anaphase because there is bending only at the centromere (primary constriction).Secondary
constrictions, which contain genes to form nucleoli are known as the nucleolar organizers.
6. Telomere-
1. Terminal part of a chromosome is known as a telomere.
2. These are not visible in the light or electron microscope, they are rather conceptual
structures.
3. Each chromosome has two telomeres. The telomere of one chromosome cannot unite with
the telomere of another chromosome due to polarity effect.
7. Satellite: It is an elongated segment that is sometimes present on a chromosome at the
secondary constriction. The chromosomes with satellite are known as sat-chromosome.
11. Functions of Chromosomes
• The main function of chromosomes is to carry the genetic material from one generation to another.
• Chromosomes play an important role and act as a guiding force in the growth, reproduction& repair
and regeneration process that is important for their survival.
• Chromosomes protect the DNA from getting tangled and damaged.
• Histone and non-histone proteins help in the regulation of gene expression.