The document discusses the shoot apical meristem, which generates the aerial organs of plants. It has three layers (L1, L2, L3) that contribute to stem and organ formation. The meristem also contains zones - a central zone of stem cells, a peripheral zone where leaves form, and a rib zone that forms the stem. The meristem maintains a population of stem cells and generates organs through coordinated cell division and differentiation.
after floral induction, the inflorescence meristem eventually forms the floral meristem. the process is controlled by an array of homeotic genes. this also involves microRNAs for their regulation
The Shoot apex is also known as the terminal bud of plants that grows from 0.1-1.0 mm and consists of the apical meristem, developing leaves and the immediate surrounding leaf primordial. The shoot apex is present in both dicot and monocot plants.
after floral induction, the inflorescence meristem eventually forms the floral meristem. the process is controlled by an array of homeotic genes. this also involves microRNAs for their regulation
The Shoot apex is also known as the terminal bud of plants that grows from 0.1-1.0 mm and consists of the apical meristem, developing leaves and the immediate surrounding leaf primordial. The shoot apex is present in both dicot and monocot plants.
Phloem differentiation
sieve elements
companion cells
The ontogeny of phloem sieve element
differentiation process of sieve elements
Phloem as a hub for systemic communication within the root meristem
Double fertilization is the process found in angiosperms in which out of the two male gametes released inside the embryo sac, one fuses with the egg cell (syngamy) and another fuse with secondary nucleus (triple fusion).
Phloem differentiation
sieve elements
companion cells
The ontogeny of phloem sieve element
differentiation process of sieve elements
Phloem as a hub for systemic communication within the root meristem
Double fertilization is the process found in angiosperms in which out of the two male gametes released inside the embryo sac, one fuses with the egg cell (syngamy) and another fuse with secondary nucleus (triple fusion).
Bryology - Masters First semester revision text.pdfAleenaRose4
A reference text for Bryology - 1. General characters and systems of classifications of Bryophytes
2. General account of the anatomy, reproduction, life history and phylogeny of Sphaerocarpales, Marchantiales,
Jungermanniales, Calobryales, Anthocerotales, Sphagnales, Andreales, Funariales and Polytrichales
3. Origin and evolution of Bryophytes- gametophytic and sporophytic.
4. A general account of fossil Bryophytes and their affinities.
5. Economic importance of Bryophytes.
safety data sheet, an introduction to cell culture, safety equipment, safe laboratory practices, ascetic techniques, sterile work area, good personal hygiene, sterile reagents and media, sterile handling, planning of cell culture labs.
blood glucose homeostasis and the role of tissues and hormones, roles of Insulin and glucagon in regulating blood glucose, regulation of glucose metabolism during exercise, insulin receptor and its mechanism
Ecology and Environmental Biology,air pollution, environmental pollution, gaseous pollutants, global environmental change, ionizing radiation, noise pollution, non-ionizing radiation, pollutants, pollution, prevention and control of air pollution, radiation damage, radiation pollution, soil pollution, sources of water pollution, types of pollution, water pollution, water recycling
Cancer and its types, all tumours are not cancer, cancer, diagnosis of cancer, how cancer differ, how cancer spread, how cancer start, how normal cells act
diagnosis of cancer, bioluminescent detection, diagnosis of cancer, haplotype mapping, imaging gene expression in vivo, types of cancer diagnosis method, ultrasound imaging
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
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AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
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Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
The prostate is an exocrine gland of the male mammalian reproductive system
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Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
2. Paleozoic Era
• The Paleozoic Era started 542 million years ago ,ended 251 million years ago
The era is usually broken down even further to six main periods.
• Cambrian: 542 to 488.3 million years ago
• Ordovician: 488.3 to 443.7 million years ago
• Silurian: 443.7 to 416 million years ago
• Devonian: 416 to 359.2 million years ago
• Carboniferous: 359.2 to 299 million years ago
• Permian: 299 to 251 million years ago
3. Introduction
• It is almost a point of definition for the algae that they are aquatic plants,
although some of them have invaded moist habitats on land.
• The useful fossil record begins with the Cambrian period of the Paleozoic
Era, over 500,000,000 years ago.
• Cambrian record, so far as plants are concerned, consists entirely of a wide
variety of algae and bacteria.
• In fact, the early Paleozoic is often referred to as the Age of Algae and
Invertebrates.
• But fossils from the Silurian period, beginning about 360,000,000 years
ago
• This include primitive land plants and it is probable that their first
appearance was in the preceding period, the Ordovician.
• When these first colonists left the waters to invade the more difficult.
4. …………
• But more varied habitats on land, the algae remained the dominant
members of the earth’s flora.
• But soon the land dwellers surpassed their aquatic progenitors.
• One of the crucial problem had to e solved before plants could invade
the land was the protection of the zygote against drying.
• In all land plants, this is accomplished, with important differences in
the details, by the retention of the zygote and the developing embryo
with in the sex organs of the maternal plants.
• For this reason, the land plants are known collectively as the
subkingdom Embryophyta.
5. The Meaning Of Evolution
Is the process of change in living populations.
The study of evolution – fundamentals branches of
biology – Evolutionary biology
It is the study of biology as a historical science, or the
study of living systems as they change through time
All living systems are products of evolutionary history
6. Evolution Of The Plant Kingdom
Plants and their classification
Algae
Bryophytes
Vascular Land Plants
Plants with Naked Seeds
Flowering Plants
7. Phylogeny Of The Eukaryotes
Amoeboid and flagellated protozoans
Origin of chloroplasts
Red algae
(Rhodophyta)
chrysophyta
Brown algae(Phaeophyta)
Pyrrophyta
Euglenophyta
Xanthophyta
Green algae(chlorophyta)
Mosses and
liverworts(bryophyte)
VASCULAR LAND
PLANTS(Tracheophyta)
Ciliated protozoans (ciliate)
TRUE
FUNGI(Eumycota)
Slime molds
Cnidaria
OTHER MULTICELLULAR
ANIMALS
Mesozoa
Sponges(Porifera)
8. Plants and their classification
• International Rules of Botanical Nomenclature specify that the plant
kingdom is to be separated into ‘divisions’ rather than ‘phyla’.
• Eichler (1883) and his contemporaries divided the entire plant
kingdom into four divisions, as follows:
• The kingdom plantae contains only those eukaryotic organisms possessing
chlorophyll pigments, plastids and also usually a cell wall .
• The ancestry of the plants is still an unsettled question
9. • Division Thallophyta: plants without embryos.
• class Algae: Thallophytes containing chlorophyll
• class fungi: Thallophytes without chlorophyll
• Division Bryophyta: plants with embryos but without vascular tissues: mosses and
their relatives
• Division Pteridophyta: vascular plants without seeds: ferns, horsetails, club mosses
and their relatives.
• Division Spermatophyta: seed plants
• class Gymnospermae: seed plants without flowers, the seed being naked
rather than enclosed in an ovary
• class Angiospermae: flowering plants, with the seeds protected in an ovary.
10. ………..
• The embryophyta include the traditional divisions Bryophyta, Pteridophyta and
spermatophyte.
• Klein and Cronquist (1967) have re-examined the classification of thallophytes and
• Cronquist,Takhtajan and Zimmerman (1966) have similarly re-examined the
classification of the embryophytes.
Division Pyrrophyta: dinoflagellates and cryptomonads
Division Chrysophyta: golden-brown algae and diatoms
Division Euglenophyta: euglena and its relatives
Division Rhodophyta: red algae
Division Phaeophyta: brown algae
Division Chlorophyta: green algae Euglena
Brown algae
Red algae
Diatoms
11. Bryophytes
• The phylum bryophyta is a relatively small group comprising the mosses, the
liverworts and the hornworts.
• These are the amphibians of the plant world.
• They have met only minimum requirements of adaptation to the terrestrial
environment.
• They are restricted to wet habitats and all of them require water for reproduction
• The embryos – multicellular-retained with female sex organs- it protecting them
from drying.
12. • All of the aerial parts of the plant are covered by a waxy cuticle
which protects the plant against drying
13. Phylogeny of the bryophytes
• Bryophytes of the many characters which they share with the
green algae.
• It is highly probable that the bryophytes were derived from an
ancestor among the green algae.
• One group of bryophytes, the hornworts, suggests relationships to
higher plants.
• While the gametophyte is a small, simple thallus, the sporophyte is
larger
• It is well supplied with chlorophyll
• But still depends upon the gametophyte for absorption of water
and minerals from the substrate
14. • The capsule has a central axis of elongate cells which suggests vascular tissue.
• The epidermis has stomata like those on the leaves of vascular plants.
• With such an array of traits suggesting those of vascular plants, it is difficult to
avoid the inference.
• that modern hornworts may be but little changed from an ancestral stock by which
bryophytes gave rise to vascular plants.
• This inference appears to misleading, for vascular plants appear in the fossil record
in the SILURIAN.
• The bryophytes appear more than 100,000,000 years later.
• Obviously if these data are correct, bryophytes cannot be ancestral to tracheophytes.
• So the weight of opinion among botanists now favors direct origin of the vascular
plants, the phylum Tracheophyta, from a chlorophytan ancestor.
15. The Shoot Apical Meristem
• Shoot system: above ground structures of
plants, leaves, buds, stems, flowers and fruits
• Nodes: where leaves are located
• Internodes: the spaces between nodes
• Buds: terminal, lateral, accessory
• Terminal Buds: located at the tip of the stem
• Terminal bud scar: indicate the amount of
growth over the past year
• Lateral Bud: found at the side of a stem
• Accessory Buds: found in pairs and are located
beside terminal or lateral buds
16.
17. meristems
• Tissues of the stem capable of cell division
• Apical Meristem: found at the tip of the stem
• Lateral Meristem: found surrounding the stem
• Growth at the apical meristem is called as primary growth.
• The 3 types of tissues, apical meristem will be connect.
• Protoderm: will eventually make the epidermis of the stem.
• This is the outer protective covering of the stem.
• Ground meristem: will make the different types of ground tissue.
Parenchyma: stores water and food
Collenchyma: supports young stems and roots
Sclerenchyma: hard protection
• Procambium: will make the vascular tissue. It consist of both
18.
19. The Shoot Apical Meristem Contains Different Functional Zones and Layers
• It consists of different functional regions that can be distinguished by the orientation of
the cell division planes and by cell size and activity
• The angiosperm vegetative shoot apical meristem usually has a highly stratified
appearance, typically with three distinct layers of cells
• These layers are designated L1, L2, and L3, where L1 is the outermost layer
• Cell divisions are anticlinal in the L1 and L2 layers; that is, the new cell wall separating
the daughter cells is oriented at right angles to the meristem surface
• Cell divisions tend to be less regularly oriented in the L3 layer
• Each layer has its own stem cells, and all three layers contribute to the formation of the
stem and lateral organs
• Active apical meristems also have an organizational pattern called cytohistological
zonation.
• Each zone is composed of cells that may be distinguished not only on the basis of their
division planes, but also by differences in size and by degrees of vacuolation
21. • The center of an active meristem contains a cluster of relatively large, highly
vacuolate cells called the central zone.
• The central zone is somewhat comparable to the quiescent center of root
meristems.
• A doughnut-shaped region of smaller cells, called the peripheral zone, flanks the
central zone. A rib zone lies underneath the central cell zone and gives rise to the
internal tissues of the stem.
• These different zones most likely represent different developmental domains. The
peripheral zone is the region in which the first cell divisions leading to the
formation of leaf primordia will occur.
• The rib zone contributes cells that become the stem. The central zone contains the
pool of stem cells, some fraction of which remains uncommitted, while others
replenish the rib and peripheral zone populations (Bowman and Eshed 2000).
22. • The underground part of the plant is called
root system.
• The underground main axis of the plant body
is called root.
• It is the prolongation of radicle of the embryo.
• It is positively geotropic or negatively phototropic.
• It is not differentiated into nodes and internodes.
• It is non-chlorophyllous or brown coloured.
• It does not possess leaves, buds, flowers and fruits.
• Lateral roots are produced from main axis in
acropetal succession.
• Lateral roots are formed from inner region of the
• main axis (pericycle).
• So these are called ENDOGENOUS ORGANS.
Root System
23. • The small hair like outgrowth present on the tips of lateral roots and main axis
are called ROOT HAIRS.
• Root hairs are exogenous organs.
• Root hairs are found in mesophytes and xerophytes and absent in hydrophytes.
• The protective layer present around the root tip is called ROOT CAP.
• Root cap is made up of a dead tissue called CALYPTROGEN. Hence it is also called
CALYPTRA.
• It is also well developed in mesophytes and xerophytes, absent in hydrophytes.
• In free floating hydrophytes root pockets are present.
24. Types of root
system
• Tap root system
The central main axis is called tap root.
Tap root is formed by the prolongation of radicle of the embryo
Lateral roots are produced obliquely in all directions from tap root
in acropetal succession.
It is most commonly found in DICOTYLEDONS.
• Fibrous root system or adventitious root system
A bunch of new roots are produced from the base of the stem as fibres. So
these roots are called fibrous roots and the root system is called fibrous
root system.
In this, roots are not formed from radicle. So these are aslo called
adventitious roots, and the root system is called adventitious root system.
It is most commonly found in MONOCOTYLEDONS.
In angiosperms two types of
root systems are present.
They are:
1.Tap root system
2.Fibrous root system or
Adventitious root system
26. Meristematic zone :
• lies just under the root cap
• quarter of a millimetre long
• root meristem generates only one
organ, the primary root
• It produces no lateral appendages.
27. Elongation zone:
• site of rapid and extensive cell
elongation
• Although some cells may continue
to divide while they elongate within
this zone
• the rate of division decreases
progressively to zero with increasing
distance from the meristem.
28. Maturation zone:
• cells acquire their differentiated characteristics
• Cells enter the maturation zone after division and elongation have
ceased
• Differentiation may begin much earlier
• but cells do not achieve the mature state until they reach this zone
• radial pattern of differentiated tissues becomes obvious in the
maturation zone
29. • Root Apical Meristems Contain Several Types of Stem Cells
• The patterns of cellular organization found in the root meristems of seed
plants
• It is substantially different from those observed in more primitive
vascular plants
• All seed plants have several stem cells
• Instead of the single stem cell found in Plants such as the water fern
Azolla.
• However, they are similar to Azolla
30. The Arabidopsis root apical meristem has the following structure:
• quiescent center is composed of a group of four cells
• Also known as the center cells in the Arabidopsis root meristem
• quiescent-center cells in the Arabidopsis root usually do not divide after
embryogenesis
cortical–endodermal stem cells:
• It form a ring of cells that surround the quiescent center.
• These stem cells generate the cortical and endodermal layers
• They undergo one anticlinal division (i.e., perpendicular to the
longitudinal axis)
• these daughters divide periclinally (i.e., parallel to the longitudinal axis)
to establish the files that become the cortex and the endodermis
31. • each of which constitutes only one cell layer in the Arabidopsis root
columella stem cells :
• the cells immediately above (apical to) the central cells
• They divide anticlinally and periclinally to generate a sector of the
rootcap known as the columella
root cap–epidermal stem cells:
• are in the same tier as the columella stem cells but form a ring
surrounding them
• Anticlinal divisions of the root cap–epidermal stem cells generate the
epidermal cell layer
• Periclinal divisions of the same stem cells, followed by subsequent
anticlinal divisions of the derivatives, produce the lateral root cap