All animals have external structures, or bodily organs on the outside. The majority of animals have a head, a body covering, limbs, and a tail of some kind. These body parts are all essential to an animal's ability to live and reproduce, despite the fact that they may appear differently on different animals.
The limbs of mammals may be modified for a particular movement. They could be taught how to swim, fly, climb, and run. More commonly known as "ricochetal locomotion," saltatory (leaping) movement has been observed in a variety of unrelated species (some marsupials, lagomorphs, and several independent lineages of rodents).
The skin of mammals, like that of other vertebrates, consists of epidermal and dermal layers. It protects against actual injury, microbiological invasion, and UV rays from the sun. skin is also important for temperature regulation, sensory perception excretion, and water regulation.
Hairs are a keratinized derivative of the epidermis of the skin and are uniquely mammalian. It is seated in an invagination of the epidermis called a hair follicle. Two distinct kinds of hair typically compose a pelage, a coat of hair. Long guard hairs protect a dense coat of shorter, insulating under hairs.
Hair must periodically molt because it is made mainly of dead cells. In some mammals (e.g., humans), molting occurs gradually and may not be noticed. Others have rapid hair loss, which could alter the characteristics of their pelage. In the fall, many mammals acquire a thick coat of insulting under hair, and the pelage color may change.
For example, the Arctic fox takes on a white or cream color with its autumn molt, which helps conceal the fox in a snowy environment. with its spring molt, the Arctic fox acquires a gray and yellow pelage
Hairs are also important for the sense of touch. The mechanical displacement of hair stimulates nerve cells associated with the hair root. Guard hairs may sometimes be modified into thick-shifted hairs called vibrissae. Vibrissae occur around the legs, nose, mouth, and eyes of very sensitive to displacement.
Air space in the hair shaft and hair trapped between hairs and the skin provides an effective insulating layer. A band of smooth muscle, called the arrector pili muscle, runs between the hair follicle and lower epidermis. when the muscle contract, the hair stands upright, increasing the amount of air trapped the in the pelage and improving its insulating properties.
Arrector pili muscles are under the control of the autonomic nervous system, which also controls a mammal's "fight-or-flight" response. In threatening situations, the hair stands on end and may give the perception of increased size and strength.
Hair color depend on the number of pigments (melanin) deposited in it and the quantity of air in the hair shaft. The pelage of most mammals is dark above and lighter underneath. This pattern them less conspicuous under most conditions. Some mammals advertised their defenses using aposematic (warning
Comparative account of derivatives of integuments sunandakumre
the integument is the natural outer protective covering of an organism or an organ, such as its skin, husk, shell, or rind.
The cutaneous Membrane (skin) And its derivatives (Exoskeleton) are together referred to as Integuments.
Skin also includes conjunctiva Of eyeballs and the external surface of eardrums and it is directly continuous with the mucous epithelial lining of the mouth rectum, nostrils, Eyelids, and urinogenital ducts.
Training manual on species identification 2017 vivekanand bharti_basic finfis...Ashish sahu
The ID tools reviewed are: Use of scientific experts (taxonomists) and folk local experts, taxonomic reference collections, image recognition systems, field guides based on dichotomous keys; interactive electronic keys (e.g. IPOFIS), morphometrics (e.g. IPez), scale and otolith morphology, genetic methods
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Homelearning behaviourInstinct and Learning Behavior
Instinct and Learning Behavior
MalaikaNovember 06, 2022
Learning and instinct have been compared throughout history and in folk biology.
While instinct focused on biologically preprogrammed mechanisms that emerge naturally in the absence of special environmental input, learning was meant to emphasise aspects of behavior and cognition that are the result of experience and training.
This distinction relates to those between learned and innate or inherited knowledge.
Instinct and learning behavior in animals
Instinct and learning in their biological setting
When viewed holistically, development's purpose is to help an animal build a repertoire of behaviours that are appropriate for its mode of existence and fit for success.
The stunning alignment of form and function is evident whether we are studying the muscular control of limb movement under negative feedback processes or the nest-building behaviours of birds, whether we are observing young animals or adults.
Animals do occasionally behave awkwardly and make mistakes, especially when placed in unnatural situations, but for the most part, their behaviour is perfectly matched to their way of life.
They find food, shelter, mate, and offspring by responding appropriately to the elements of their environment. How does behaviour develop this almost perfect fit? How is it able to grow so well?
People have been captivated by this query for centuries because we have always been animal observers. Of course, we have less often focused on how their behaviour changes than on their "nature" as beings that critically share the "spark of life" with us.
Even though we may take advantage of or ignore other species' needs in favour of our own, we cannot simply ignore them. This fact has caused some very different attitudes. Animals have occasionally been revered as deities.
How young animals grow up?
Methods of capturing animals
How many zoos does Pakistan have? and where?
The Egyptians kept a sacred bull named Apis and frequently depicted their writing god, Thoth, as a hamadryas baboon (Papio hamadryas). On the other hand, the Madagascan aye-aye (Daubentonia madagascariensis), a species of lemur, was hunted until recently because people believed it to be a devil's incarnation (Fig. 2).
The animal as god, the animal as devil.
(a) The animal as god, (b) The animal as devil.
Cats and toads were frequently accused of being the "familiars" of women accused of practising witchcraft in Europe. However, St. Francis was known for preaching to animals, referring to them as a part of Creation and perhaps even as having immortal souls.
We can now put superstitions to rest, but there is still much to learn about the sentience of animals, and we will discuss this in more detail later. Most pet owners will undoubtedly give their animal companions some human traits, even if in jest.
At one extreme, we might have animals like Badger, Ratty, Mole, and Toad fro
Young animals grow up
If the zygote can grow in and interact with a suitable environment, it contains all the information required to create a new organism. It stands to reason that some aspects of embryology must be considered when studying the development of behaviour. For instance, the way the nervous system's fundamental structure is built, but we must go much further than this.
Young animals grow up
It is entirely possible to argue that in some animals, behavioural development continues throughout life. Long after an animal is independent, its behaviour may still change. Learning could therefore be seen as a form of development, and young animals occasionally learn a lot as they grow. But in this section, we'll focus on other behavioural changes that frequently occur early in life, often quickly and dramatically.
It is important to understand that young animals must always be fully functional creatures capable of acting appropriately in their own worlds. They cannot simply be incomplete creatures or inadequate stages on the path to adulthood.
Some animals are protected during their early development by an eggshell or uterus or by watchful parents, but others are free-living and must care for themselves completely. Young animals may develop into miniature adults as they grow in size over time, but in order to keep up, their behavioural responses must also adapt.
Although young cuttlefish (Sepia) start out and continue to be carnivores, at first, they can only kill tiny crustacea that are disregarded as prey once the cuttlefish has grown. As they grow closer to adult size, they move on to food that is bigger and bigger, which requires a change in the behaviour patterns used to find and catch prey.
Even more drastic behavioural and morphological changes may occur in some cases because some young animals live entirely different lives than do adults. Tadpoles are herbivores that swim and breathe like fish before changing into land-dwelling carnivorous frogs or toads.
Eristalis tenax, an aquatic filter-feeding rat-tailed maggot that breathes through a long snorkel tube at its back, transforms into a flower-feeding hoverfly (see Fig. 2). Young and adult require almost entirely different behavioural repertoires for these life histories.
Rat-tailed maggot | Flower-feeding hoverfly
These alterations mean that development frequently has to produce patterns that only function for a portion of an animal's life before disappearing. The specific coordinated movements that cockroaches use to emerge from their individual eggshells as well as the protective case that bundles a group of eggs together were both described by Provine in 1976. These movements, which are only observed on this one occasion, consist of a series of reversed waves of contraction along the body from the tail to the head.
They appear at the exact right time, at the end of the egg stage's development, and are used to propel the young cockroach nymph into the following growth
Comparative account of derivatives of integuments sunandakumre
the integument is the natural outer protective covering of an organism or an organ, such as its skin, husk, shell, or rind.
The cutaneous Membrane (skin) And its derivatives (Exoskeleton) are together referred to as Integuments.
Skin also includes conjunctiva Of eyeballs and the external surface of eardrums and it is directly continuous with the mucous epithelial lining of the mouth rectum, nostrils, Eyelids, and urinogenital ducts.
Training manual on species identification 2017 vivekanand bharti_basic finfis...Ashish sahu
The ID tools reviewed are: Use of scientific experts (taxonomists) and folk local experts, taxonomic reference collections, image recognition systems, field guides based on dichotomous keys; interactive electronic keys (e.g. IPOFIS), morphometrics (e.g. IPez), scale and otolith morphology, genetic methods
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Homelearning behaviourInstinct and Learning Behavior
Instinct and Learning Behavior
MalaikaNovember 06, 2022
Learning and instinct have been compared throughout history and in folk biology.
While instinct focused on biologically preprogrammed mechanisms that emerge naturally in the absence of special environmental input, learning was meant to emphasise aspects of behavior and cognition that are the result of experience and training.
This distinction relates to those between learned and innate or inherited knowledge.
Instinct and learning behavior in animals
Instinct and learning in their biological setting
When viewed holistically, development's purpose is to help an animal build a repertoire of behaviours that are appropriate for its mode of existence and fit for success.
The stunning alignment of form and function is evident whether we are studying the muscular control of limb movement under negative feedback processes or the nest-building behaviours of birds, whether we are observing young animals or adults.
Animals do occasionally behave awkwardly and make mistakes, especially when placed in unnatural situations, but for the most part, their behaviour is perfectly matched to their way of life.
They find food, shelter, mate, and offspring by responding appropriately to the elements of their environment. How does behaviour develop this almost perfect fit? How is it able to grow so well?
People have been captivated by this query for centuries because we have always been animal observers. Of course, we have less often focused on how their behaviour changes than on their "nature" as beings that critically share the "spark of life" with us.
Even though we may take advantage of or ignore other species' needs in favour of our own, we cannot simply ignore them. This fact has caused some very different attitudes. Animals have occasionally been revered as deities.
How young animals grow up?
Methods of capturing animals
How many zoos does Pakistan have? and where?
The Egyptians kept a sacred bull named Apis and frequently depicted their writing god, Thoth, as a hamadryas baboon (Papio hamadryas). On the other hand, the Madagascan aye-aye (Daubentonia madagascariensis), a species of lemur, was hunted until recently because people believed it to be a devil's incarnation (Fig. 2).
The animal as god, the animal as devil.
(a) The animal as god, (b) The animal as devil.
Cats and toads were frequently accused of being the "familiars" of women accused of practising witchcraft in Europe. However, St. Francis was known for preaching to animals, referring to them as a part of Creation and perhaps even as having immortal souls.
We can now put superstitions to rest, but there is still much to learn about the sentience of animals, and we will discuss this in more detail later. Most pet owners will undoubtedly give their animal companions some human traits, even if in jest.
At one extreme, we might have animals like Badger, Ratty, Mole, and Toad fro
Young animals grow up
If the zygote can grow in and interact with a suitable environment, it contains all the information required to create a new organism. It stands to reason that some aspects of embryology must be considered when studying the development of behaviour. For instance, the way the nervous system's fundamental structure is built, but we must go much further than this.
Young animals grow up
It is entirely possible to argue that in some animals, behavioural development continues throughout life. Long after an animal is independent, its behaviour may still change. Learning could therefore be seen as a form of development, and young animals occasionally learn a lot as they grow. But in this section, we'll focus on other behavioural changes that frequently occur early in life, often quickly and dramatically.
It is important to understand that young animals must always be fully functional creatures capable of acting appropriately in their own worlds. They cannot simply be incomplete creatures or inadequate stages on the path to adulthood.
Some animals are protected during their early development by an eggshell or uterus or by watchful parents, but others are free-living and must care for themselves completely. Young animals may develop into miniature adults as they grow in size over time, but in order to keep up, their behavioural responses must also adapt.
Although young cuttlefish (Sepia) start out and continue to be carnivores, at first, they can only kill tiny crustacea that are disregarded as prey once the cuttlefish has grown. As they grow closer to adult size, they move on to food that is bigger and bigger, which requires a change in the behaviour patterns used to find and catch prey.
Even more drastic behavioural and morphological changes may occur in some cases because some young animals live entirely different lives than do adults. Tadpoles are herbivores that swim and breathe like fish before changing into land-dwelling carnivorous frogs or toads.
Eristalis tenax, an aquatic filter-feeding rat-tailed maggot that breathes through a long snorkel tube at its back, transforms into a flower-feeding hoverfly (see Fig. 2). Young and adult require almost entirely different behavioural repertoires for these life histories.
Rat-tailed maggot | Flower-feeding hoverfly
These alterations mean that development frequently has to produce patterns that only function for a portion of an animal's life before disappearing. The specific coordinated movements that cockroaches use to emerge from their individual eggshells as well as the protective case that bundles a group of eggs together were both described by Provine in 1976. These movements, which are only observed on this one occasion, consist of a series of reversed waves of contraction along the body from the tail to the head.
They appear at the exact right time, at the end of the egg stage's development, and are used to propel the young cockroach nymph into the following growth
Circulation, Gas Exchange, and Temperature Regulation in Mammals.pdfMammalssite
The hear of birds and mammals are superficially similar. Both are four-chambered pumps that keep blood in the systematic and pulmonary circuits separate, and both evolved from the hearts of the ancient tetrapodomorphs. Their similarities, however, are a result of adaptations to active lifestyles. The evolution of similar structure structures in different lineages is called convergent evolutions. The mammalian heart evolved from the synapsid lineage, whereas the avian heart evolved within the diapsid archosaur lineage.
Vertebrate Heart Possible Sequence in the Evolution of the Vertebrate Heart. One of the most important adaptations in the circulatory system of eutherian mammals concerns the distribution of respiratory gases and nutrients in the fetus.
Exchanges between maternal and fetal blood occur across the placenta. Although maternal and fetal blood vessels are intimately associated, no blood actually mixes. Nutrients, gases, and waste simply diffuse between maternal and fetal blood supplies. Mammalian Circulatory System
(Figure 2) Mammalian Circulatory System. Blood entering the right atrium of the fetus is returning from the placenta and is highly oxygenated. Because fetal lungs are not inflated, resistance to blood flow through the pulmonary arteries is high. Therefore, most of the blood entering the right atrium bypass the right ventricle and passes instead into the left atrium through a valved opening between the atria. However, some blood from the right atrium does enter the right ventricle and the pulmonary artery. Because of the resistance at the inflated lungs, most of this blood is shunted to the aorta through a vessel connecting to the aorta and the left pulmonary artery. External Structure and locomotion in Mammals Excretion and Osmoregulation In Mammals Reproduction and Development in Mammals. At birth, the placenta is lost and the lungs are reduced, and blood flow to them increases. Flow through the ductus arteries decreases, and the vessels are gradually reduced valve of the foramen ovale closes and gradually fuses with the tissue separating the right and left arita (figure 2b). Gas Exchange in Mammal. For efficient gas exchange at high metabolic rates, adaptations are necessary. Most mammals have separate nasal and oral cavities and longer snouts, which provide an increased surface area of warming and moistening inspired air. Respiratory passageways are highly branched, and large surface areas exist for gas exchange. Mammalian lungs resemble highly vascular spongy, rather than saclike structures of amphibians and a few reptiles.
Mammalian lungs, like those of reptiles, inflate using a negative pressure mechanism. Mammals have a muscular diaphragm that separates the thoracic and abdominal cavities, unlike reptiles and birds. Inspiration results from the diaphragm's contraction and the rib cages' expansion, both of which decrease the intrathoracic pressure and allow air to enter the lungs. Expiration is normally by elastic rec
There are different components in the nucleus. A thin but distinct covering called the nuclear envelop, also known as the karyotheca, defines its perimeter. The solutes of the nucleus are dissolved in a clear fluid substance inside the envelope known as nucleoplasm, nuclear sap, or karyolymph.
The nuclear matrix, a network of protein-containing fibrils, the chromatin, which is made up of finely entwined nucleoprotein filaments, and one or more spherical structures known as nucleoli are all suspended in the nucleoplasm (singular, nucleolus). The nucleus is devoid of microtubules and membranes.
However, the nuclei of protozoans that form a mitotic spindle within the nuclear envelop contain microtubules. The nucleus is made up of 9–12% DNA, 5% RNA, 3% lipids, 15% simple basic proteins like histone or protamines, and 65% complex acid or neutral proteins. It also contains organic phosphates, inorganic salts or ions like Mg++, Ca++, and Fe++, as well as polymerases for the synthesis of DNA and RNA.
Functions
The nucleus serves as the cell's administrative hub. It performs the following primary purposes: By controlling the production of structural proteins, it keeps the cell alive. By directing the synthesis of enzymatic proteins, it controls cell metabolism. In addition to information about structure and metabolism, it also contains genetic material for the organism's behaviour, development, and reproduction. When necessary, it causes cell replication. It is where ribosome subunit formation takes place. By keeping only a select few genes active, it causes cell differentiation. It produces genetic changes that lead to evolution. The nuclear envelop separates the cytoplasm from the nucleoplasm. It is made up of an outer and an inner unit membrane. Each unit membrane is a trilaminar lipoprotein, similar to the plasma membrane, and is about 75Å thick. The inter membrane or perinuclear space, which divides the two unit membranes, is present between them. Its width is about 250Å. Ribosomes and polysomes are found in abundance on the outer, or cytoplasmic, surface of the outer membrane, which is also rough. These ribosomes continue to produce proteins. RER and the outer membrane occasionally blend together. As a result, the channels of the RER are continuous with the perinuclear space. Ribosomes are absent from the inner membrane of the nuclear envelope, but it has a thick layer called the nuclear lamina that is closely connected to its inner or nucleoplasmic surface.
The nuclear lamina is a network of filaments that ranges in thickness from 30 to 100 nm and is made up of lamin A, B, and C proteins. The inner membrane is supported and given shape by the nuclear lamina. The majority of the chromosomes are kept outside the nucleus by this connection between chromatin and the inner membrane. During mitosis, it also affects how the nuclear envelope degrades and then reforms. Nuclear Pores: The nuclear pores, which regulate the passage of some molecules and parti
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
Homecell divisionCell division
Cell division
Miller November 05, 2022
Every living organism depends on the growth and multiplication of its cells for growth and development because a multicellular organism begins as a single cell and undergoes repeated division. The characteristic trait of all living things is an increase in cell size brought on by growth. The cell starts to divide once its growth has reached its maximum. An organism grows vegetatively when its number of cells increases through cell divisions that follow a geometric progression. The three stages of cell division, which is a continuous and dynamic process, are as follows:
Replicating the genome or DNA
Karyokinesis, or nuclear division
Cytokinesis, also known as cell division
Based on the number of genomes present in the daughter cells in comparison to the dividing parent cell, there are two types of cell division: mitosis and meiosis.
1. Mitosis- W. Flemming first used the word mitosis in 1882. Mitosis, also known as somatic division, is the process by which a body cell divides into two daughter cells, each of equal size and with the same number of chromosomes as the parent cell.
2. Meiosis- J. Meiosis was the first to use the term. B. Farmer and J. Smith in 1905 Moore, E. Only the gonads (germ mother cells) undergo meiosis during the development of gametes like sperm and ovum. Meiosis is the process by which chromosomes go from having two copies, or 2N or diploid, to having only one copy, or N or haploid. Additionally known as the reduction process. Every cell that is able to divide undergoes a regular cycle of alterations known as the cell cycle. A cell is diploid when it begins its cycle.
Phases of cell cycle
The cell cycle has two phases: the long interphase, also known as Iphase, and the short mitotic, also known as M-phase, phases. 1. Interphase-
The interphase is the period of time between telophase's conclusion and the start of the following Mphase. The stage is long and complicated, lasting between 10 and 30 hours. The cell develops during this phase by producing biological molecules like lipids, proteins, carbohydrates, and nucleic acids.
First gap, also known as the G1 phase, second gap, also known as the G2 phase, and synthetic phase make up the interphase.
(i) G1 phase- The G1 phase represents the duration between the previous mitosis and the start of DNA synthesis. During this phase, a newly formed cell begins to grow. During this stage, a wide range of biological molecules—including RNAs, proteins, lipids, and some non-histones—are created.
In order to prepare for the DNA replication that will occur next to it, normal metabolism is carried out. This phase does not involve DNA synthesis. (ii) S Phase- Each chromosome is duplicated during this phase by replicating new DNA molecules using the existing DNA as a template. Only in S-phase do histone protein and their mRNA, some non-histone protein, and new nucleosome formation take place. Most eukary
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
1. External Structure and locomotion
All animals have external structures, or bodily organs on the outside. The majority of animals
have a head, a body covering, limbs, and a tail of some kind. These body parts are all
essential to an animal's ability to live and reproduce, despite the fact that they may appear
differently on different animals.
The limbs of mammals may be modified for a particular movement. They could be taught
how to swim, fly, climb, and run. More commonly known as "ricochetal locomotion," saltatory
(leaping) movement has been observed in a variety of unrelated species (some marsupials,
lagomorphs, and several independent lineages of rodents).
Skin
The skin of mammals, like that of other vertebrates, consists of epidermal and dermal
layers. It protects against actual injury, microbiological invasion, and UV rays from the sun.
skin is also important for temperature regulation, sensory perception excretion, and water
regulation.
2. Hair
Hairs are a keratinized derivative of the epidermis of the skin and are uniquely mammalian.
It is seated in an invagination of the epidermis called a hair follicle. Two distinct kinds of hair
typically compose a pelage, a coat of hair. Long guard hairs protect a dense coat of shorter,
insulating under hairs.
Hair must periodically molt because it is made mainly of dead cells. In some mammals (e.g.,
humans), molting occurs gradually and may not be noticed. Others have rapid hair loss,
which could alter the characteristics of their pelage. In the fall, many mammals acquire a
thick coat of insulting under hair, and the pelage color may change.
For example, the Arctic fox takes on a white or cream color with its autumn molt, which helps
conceal the fox in a snowy environment. with its spring molt, the Arctic fox acquires a gray
and yellow pelage (see figure 2).
(Figure 2) Arctic fox
Hairs are also important for the sense of touch. The mechanical displacement of hair
stimulates nerve cells associated with the hair root. Guard hairs may sometimes be modified
into thick-shifted hairs called vibrissae. Vibrissae occur around the legs, nose, mouth, and
eyes of very sensitive to displacement.
Air space in the hair shaft and hair trapped between hairs and the skin provides an effective
insulating layer. A band of smooth muscle, called the arrector pili muscle, runs between the
hair follicle and lower epidermis. when the muscle contract, the hair stands upright,
increasing the amount of air trapped the in the pelage and improving its insulating properties.
Arrector pili muscles are under the control of the autonomic nervous system, which also
controls a mammal's "fight-or-flight" response. In threatening situations, the hair stands on
end and may give the perception of increased size and strength.
● Circulation, Gas Exchange and Temperature Regulation in Mammals
● Excretion and Osmoregulation In Mammals
● Reproduction and Development in Mammals
3. Hair color depend on the number of pigments (melanin) deposited in it and the quantity of
air in the hair shaft. The pelage of most mammals is dark above and lighter underneath. This
pattern them less conspicuous under most conditions. Some mammals advertised their
defenses using aposematic (warning) coloration. The contrasting marking of a skunk is a
familiar example.
Pelage is reduced in large mammals from hot climates (such as those seen in elephants and
hippopotamuses) and some aquatic mammals (e.g. Whales) that often have fatty insulation.
A few mammals (e.g. naked mole rats) have almost no pelage (see figure 3).
Claws
Claws are present in all amniote classes. For locomotion, as well as for offensive and
defensive behaviors. Claws form from accumulations of keratin that cover the terminal
phalanx (bone) of the digits. Some mammals, they are specialized to form nails or hooves
(see figure 4).
4. Glands develop from the epidermis of the skin. Sebaceous (oil) glands are associated with
hair follicles, and their oily secretion lubricates and waterproofs the skin and hair. most
mammals also possess sudoriferous (sweat) glands.
Small sudoriferous glands (eccrine glands) release watery secretions used in evaporative
cooling. Large sudoriferous glands (apocrine glands) secrete a mixture of salt, urea, and
water, which microorganisms on the skin convert to odorous products.
Scent or musk glands
Scent or musk glands are around the face, feet, or anus of many mammals. These glands
secrete pheromones, which may be involved with defense, species ad sex recognition, and
territorial behavior.
Mammary gland
Mammary glands are functional in female mammals and are present, but non-functional, in
males. The milk that mammary glands secrete contains water, carbohydrates (especially the
sugar lactose), fats, protein, minerals, and antibodies. Mammary glands are probably
derived evolutionarily from apocrine glands and usually contain substantial fatty deposits.
5. Monotremes have mammary glands that lack nipples. The glands discharge milk into
depressions on the belly, where the young lap it up. In other mammals, mammary glands
open via nipples or teats, and the young suckle for their nourishment (see figure 5).
The Skull and Teeth
The skull of mammals shows important modifications of the reptilian pattern. One feature
that zoologists used to distinguish reptilian from mammal skulls is the methods of jaw
articulation. In reptiles, the jaws articulate at two small bones at the rear of the jaw. In
mammals, these bones have moves into the middle ear, and along with the stapes, form the
middle ear ossicles. A single bone of the lower jaw articulates the mammalian jaw.
A secondary palate evolved twice in vertebrates in the archosaur lineage and in the
synapsid lineage. In some therapsids, small, shelf-like extensions of bones (the hard palate)
partially separated the nasal and oral passageways. The soft palate, a posterior extension
of the secondary palate in animals, separates the mouth cavity from the nasal passages
almost completely.
Some mammals chew their food before ingesting it, like other vertebrates that do. The more
extensive secondary palate allows mammals to breathe while chewing, Breathing needs to
stop only briefly during swallowing (see figure 6).
6. Teeth's arrangement and form are important indicators of mammalian lifestyle. In reptiles, the
teeth are uniformly conical, a condition referred to as homodont. In mammals, the teeth are
open and specialized for different functions, a condition called heterodont. Recall that in
reptiles other than archosaurs, teeth were acrodont and attached along the top or inside of
the jaw.
In mammals ( as well as crocodylians) teeth is thecodont. That is, teeth are set into sockets
of the jaw. For most of their lives, mammals have two sets of teeth. Deciduous or milk
teeth, which appear before or soon after birth, are the first teeth. Permanent teeth come in to
replace these missing pieces. The term "diphyodont condition" relates to this single tooth
replacement.
Adult mammals have up to four kinds of teeth.
1. Incisors
Incisors are the most anterior teeth in the jaws. They are usually chisel-like and used for
gnawing or nipping.
2. Canine
Canine are often long, stour, and conical. They are usually for catching, killing, and tearing
prey. The Canine and incisor have single roots.
7. 3. Premolars
Premolars are positioned next to the canine and have one or two roots and truncated
surfaces for chewing.
4. Molars
Molars have broad chewing surfaces and two (upper molars) or three (lower molars) roots.
Mammalian species have a characteristic number of each kind of adult tooth. Zoologists use
a dental formula to characterize taxa It is an expression of the number of teeth of each kind
in one-half of the upper and lower jaws. The teeth of the upper jaws are listed below those of
the lower jaws and in the following order: Incisors, Canine, Premolar, and Molars. For
example:
Human Beaver
2 ∙ 1 ∙ 2 ∙
3
1 ∙ 0 ∙ 1 ∙ 3
2 ∙ 1 ∙ 2 ∙
3
1 ∙ 0 ∙ 1 ∙ 3
Mammalian teeth (dentition) may be specialized for a particular diet. In some mammals, the
dentition is reduced, sometimes to the point of having no teeth, For example, armadillos and
the giant anteater (order Edentata) feed on termites and ants, and their teeth are reduced.
Some mammals (e.g. humans, order primates; and pigs, order Artiodactyla) are omnivorous;
they feed on a variety of plants and animal materials. They have teeth with flat grinding
surfaces for rupturing plant cell walls in the back and teeth with sharp ripping and piercing
surfaces in the front (see figure 7).
8. Mammals that eat plant material often have flat, grinding posterior teeth and incisors, and
sometimes have canines modified for nipping plant matter (e.g. horses, order
Perissodactyla; deer, order Artiodactyla) or gnawing (e.g. rabbits, order Lagomorpha;
beavers, order Rodentia) (figure 4b and c). In rodents, the incisor grows throughout life.
Although most mammals have enamel covering the entire tooth, rodents have enamel only
on the front of their incisors.
The teeth are kept sharp by slower wear in front than in the back. A gap called the diastema
separates the interior food-procuring teeth from the posterior grinding teeth. The diastema
results from an elongation of the snout that allows the interior teeth to reach close to the
ground or into narrow openings to procure food.
The posterior teeth have a high, exposed surface (crown) and continuous growth, which
allow these teeth to withstand years of grinding tough vegetation.
Canines and incisors are used by predatory mammals to catch, kill, and tear prey. In
members of the order Carnivora (e.g. coyotes, dogs, and cats), the fourth upper premolars
and first lower molars form a scissor-like shearing surface, called the carnassial apparatus,
that is used for cutting flesh from prey (figure 4d).
The Vertebral Column
The Vertebral column of mammals is divided into five regions. As with reptiles and birds, the
first two cervical vertebrae are the atlas and axis. Five other cervical vertebrae usually follow.
Even the giraffe and Whale have seven neck vertebrae, which are greatly elongated or
9. compressed, respectively. In contrast, tree sloths have either six or nine cervical vertebrae,
and the manatee has six cervical vertebrae.
The trunk is divided into thoracic and lumber regions, as is the case for birds. In Mammals,
the division is correlated with their methods of breathing. The thoracic region contains the
ribs. Most ribs connect to the thoracic vertebrae and to the sternum via costal cartilages.
Other ribs are attached only to the thoracic vertebrae or to the other ribs through cartilages.
All ribs protect the heart and lungs. The articulation between the thoracic vertebrae provides
the flexibility needed in turning, climbing, and lying on the side to suckle young. Lumber
vertebrae have interlocking processes that give support, but little freedom of movement.
Appendicular skeleton
The appendicular skeleton of mammals rotates under the body so that the appendages are
usually directly beneath the body. Joints usually limit the movement of appendages to the
single anteroposterior plan, causing the tips of the appendages to move in long arcs.
The bones of the pelvic girdle are fused in the adult, a condition that is advantageous for
locomotion but presents problems during the birth of offspring. In a pregnant female, the
ventral joint between the halves of the pelvis the public symphysis loosens before birth,
allowing the pelvis to spread during birth.
Muscles
Most mammals, they generated the weight of the body because the appendages are located
directly beneath the body. Upper appendages and girdles contain most of the body's muscle
mass. Manny running mammals (e.g. deer order Artiodactyla) have little muscle in their
lower leg that would slow leg movement. Instead, tendons run from muscles high in the leg
to cause movement at the lower joints.
● Human respiratory system
● Endocrine System of Mammals
● The Heart and Circulatory system of Mammals