Cells and tissues
Chapter#04th
Define
the following in your own wordings?
Turgor pressure:
The outward
pressure exerted by internal water.
Tissue:
Group of
similar cells specialized for performance of a common function.
Semi permeable:
Means a
membrane which allow some specific molecules to pass.
Ribosomes:
Are the sites
of protein synthesis. These are tiny granular structure that are either
floating freely in cytoplasm or are bound.
Plastids:
Plastidsis a
membrane bound organelle that only occur in the cells of plants and
photosynthetic protists.
Plasmolysis:
The shrinkage
of cytoplasm.
Pinocytosis:
It is the type
of endocytosis in which cell takes a liquid in the form of droplets.
Phagocytosis:
It is the type
of endocytosis in which cell ingest a solid particle by the in folding of cell
membrane
Passive transport:
Movement of
substances from their higher concentration to lower concentration, energy is
not needed in this process.
Osmosis:
Movement of
water across a semi permeable membrane from a solution of lesser solute
concentration to a solution of higher solute concentration’
Organelle:
Organelle is a
small structure within the cell that perform dedicated function.
Nucleus:
Nucleus is an
organelle of the cell which control all its activity and also called the brain
of cell.
Muscle tissue:
Undergoes
contraction and share role in movements in animal body.
Mitochondrion:
Mitochondrion are
double membrane bounded structure found only in eukaryotes. These are major
energy production centers.
Lysosomes:
Are single
membrane bounded organelles’ contain strong digestive enzymes and work for
breakdown of food and waste materials in the cells.
Leucoplast:
Leucoplast are
the type of plastids. They are colourless and store, starch, proteins and
lipids.
Isotonic solution:
Have equal
concentration of solute.
Hypotonic solution:
Has relatively
less solute.
Hypertonic solution:
Has relatively
more solute.
Golgi apparatus:
In the cell,
the complete set of flattened sacs (cisternae). It is discovered by Camillio
Golgi
Facilitated diffusion:
The movement of
molecules from their higher concentration to their lower concentration with the
help of carrier protein.
Epithelial tissue:
Covers the
outside of body and lines organs and activities.
Endoplasmic reticulum:
Is a network of
interconnected channels that extends from cell membrane to nuclear envelope.
Diffusion:
Movement of
molecules from their higher concentration to their lower concentration.
Cytoplasm:
Cytoplasm is
the semi-viscous and semitransparent substances between plasma membrane and
nuclear envelope.
Connective tissue:
Serves as a
connective function. It supports and binds other tissues.
Chromoplast:
In plants
contain pigments associated with bright colors and are present in the cells of
flower petals and fruits.
Chloroplast:
Chloroplast are
the sites of photosynthesis in eukaryotes.
Centrioles:
Animals and
many unicellular organisms have hollow and cylindrical organelles known as
centrioles, it help in the formation of spindle fibers during cell division.
Cell wall:
Cell wall is a
non-living and strong component of cell, located outside the plasma membrane in
plants, fungi and many plant like protest.
Cell theory:
Cell theory is
presented by Schleiden and Schwann. It is regarded as one of the most
fundamental knowledge in biology about basic unit of life.
Cell membrane:
All prokaryotic
cells have a thin and elastic membrane covering the cytoplasm in cell membrane.
It is semi-permeable in nature.
Cell:
Is the basic
structural and functional unit of life.
Active transport:
The movement of
molecules or substance from their lower concentration to their higher
concentration by the use of energy.
Cell Cycle
Chapter#05th
Define the
following in your own wordings?
Anaphase:
It is a third phase of cell division.
In which each kinetochore fiber pulls toward the originating centrosome and
divides sister chromatid or homologues pair.
Apoptosis:
is the main type of programmed cell
death. During apoptosis, cell shrinks and become rounded due to the breakdown
of cytoskeleton by enzymes.
Benign:
If the tumor remain in their original
location for a long time they are called benign tumors.
Budding:
Is a type of asexual reproduction. In
which cell reproduce only by bud.
Cell cycle:
The series of events from the time a cell
produced until it completes mitosis and produces new cells.
Chiasmata:
The complexes formed between the
non-sister chromatids of homologous chromosomes during meiosis 1 is called
chiasmata.
Crossing over:
The exchange of segments between the
non-sister chromatids of homologous chromosomes during meiosis 1.
G0 phase:
The phase of cell cycle in which
remains quiescent and does not divide or prepare for division.
G1 phase:
The phase of inter phase in which the
cell increases its supply of proteins, makes new organelles, grows in size and
makes enzymes for the next phase.
G2 phase:
The phase of interphase in which the
cell prepares proteins for the production of spindles fibers.
Homologous chromosomes:
The chromosomes which have the same
morphology are called homologous chromosomes.
Interphase:
The phase of cell cycle between two
successive divisions is called interphase.
Karyokinesis:
Karyo=nucleus and kinesis= division.
The division of the nucleus is called karyokinesis.
Kinetochore:
The complex made of proteins that is
attached with the centromere of the chromosomes is called kinetochore.
M phase:
Mitotic phase of the cell cycle is
called M phase.
Malignant:
If tumors invade other tissues, they
are called malignant tumor and their cells are called cancerous cells.
Metaphase:
The phase of cell division in which
two kinetochore spindle from opposite sides attach with each chromosome (in
meiosis –ll and mitosis) or with homologous pair (in meiosis 1) and metaphase
plate is formed.
Metaphase plate:
The arrangement of chromosomes on
spindle fibers along the equator of the cell.
Mitosis:
The cell division in which the
daughter cell has the same number of chromosomes as were present in the parent
cell.
Necrosis:
Necrosis is the accidental death of
cells and living tissues.
Non sister chromatids:
The chromatids of two homologous
chromosomes, but not of the same chromosomes.
Phragmoplast:
The cell plate formed during
cytokinesis is called phragmoplast.
Prophase:
The first phase of the cell division.
S_phase:
The phase in interphase during which
the chromosomes are duplicated i.e. new chromatids are formed.
Sister chromatids:
Chromatids of a chromosomes are
called sister chromatids.
Spindle:
The fibers at which chromosomes attach
during cell division.
Synapsis:
The homologous chromosomes lined up
with each other and form pairs by a process called synapsis.
Telophase:
The last phase of karyokinesis during which nuclear envelops
is reformed and chromosomes uncoil to form chromatin.
Differential features of apoptosis
and necrosis
ENZYMES
Chapter#6th
Define the
following scientificterms in your own wording:
Activation energy:
Minimum
energy required to start a reaction is called activation energy.
Active site:
Only a small
portion of enzyme molecule is directly involved in catalysis. This catalytic
region is known as active site.
Amylase:
Amylase is
an enzyme which only works on carbohydrate or starch.
Anabolism:
Anabolism is
a type of metabolism in which small molecules combine with each other and make
large and complex molecules.
Biocatalyst:
The catalyst
which is used to speed up the biochemical reaction is called biocatalyst.
Catabolism:
Catabolism
is a process in which large and complex molecules break into small and simple
molecules with release of energy.
Catalyst:
Catalyst is
the substance which speed up the chemical reactions. It does not directly take
part in a chemical reaction.
Coenzyme:
If organic
factors are loosely attached with enzyme, they are called coenzymes.
Cofactor:
The
non-protein molecules or ions required by enzymes for its activity is called
cofactor.
Denaturation:
Damage or
loss of structure of a molecule is called denaturation.
Optimum pH:
All enzymes
work at their maximum rate at a narrow range of pH called as optimum pH.
Optimum temperature:
Every enzyme
works at its maximum rate at a specific temperature called as the optimum
temperature for the enzyme.
Enzyme:
Enzyme Are
proteins that catalyzed biochemical reactions and are not changed during the
reaction.
Enzymes substrate complex:
Enzyme
substrate complex is a temporary complex which is formed when enzymes attaches
with substrate.
Lipase:
Lipase is an
enzyme which works on lipids only.
Lock and key model:
According to
this model, both enzyme and substrate possess specific shapes that fit exactly
into one another.
Metabolism:
Metabolism
is a set of biochemical reactions that occur in living organisms in order to
maintain life.
Product:
The
molecules those are formed as the result of enzymatic reaction are called
products.
Saturation:
The state at
which all the active sites of the enzymes are occupied and any more substrate
molecules do not find free active sites is called saturation.
Substrate:
The
molecules at which enzymes act are called substrates.
Bioenergetics
Chapter#7th
Define the following terms in your own wording:
Acetyl-Co A:
A compound formed by the combination of acetate with
co-enzyme A.
Adenine:
Is a double ring nitrogenous base.
ADP:
Adenosine di phosphate, formed of an adenine, ribose and two
phosphate groups.
Aerobic
respiration:
Type of respiration which occurs in the presence of oxygen.
Alcoholic fermentation:
Occurs in bacteria, yeast etc. in this type, pyruvic acid is
further broken down into alcohol and CO2.
AMP:
Adenosine mono phosphate, formed of an adenine, ribose and
one phosphate group.
Anabolism:
Includes the biochemical reactions in which larger molecules
are synthesized.
Anaerobic respiration:
Type of respiration which occurs in the absence of oxygen.
ATP:
Adenosine tri phosphate, the major energy currency of all
cells in a nucleotide.
Autotrophic:
Such organisms which can prepare their food by
themselves.eg. Plants.
Bioenergetics:
Bioenergeticsis
the study of energy relationships and energy transformation in living
organisms.
Calvin cycle:
The summery of the events of dark reactions, also known as
Calvin cycle.
Chlorophyll:
The green pigment inside the chloroplasts of plant cells. It
enables photosynthesis to take place.
Co-enzyme-A:
Co-enzyme A is an organic cofactor which is loosely attach
with enzyme.
Electron transport chain:
Electron transport chainis the final step of cellular
respiration.
FAD:
Flavin adenine dinucleotide is a co enzyme.
Glycolysis:
Breakdown of glucose is called glycolysis.
Krebs cycle:
In Krebs cycle the pyruvic acid molecules are completely
oxidized, along with the formation of ATP, NADH and FADH2.
Lactic acid fermentation:
In this type of anaerobic respiration, each pyruvic acid
molecule is converted into lactic acid (C2H6O3)
Light dependent reactions:
Such reactions which need light for their completion are
called light dependent reactions.
Limiting factors:
An environmental factor the absence or deficiency of which
can decrease the rate of a metabolic reaction, is called limiting factor for
that reactions.
Mesophyll:
The leaf tissues specialized for photosynthesis.
Metabolism:
Metabolism is the set
of biochemical reactions that occur in living organisms to maintain life.
NAD:
Nicotine amide adenine dinucleotide. A coenzyme used in
oxidation-reduction reactions.
Oxidation:
The loss of electrons is called oxidation.
Photolysis:
A process in which complete substance are broken down with
the help of light.
Photosynthesis:
Is the synthesis of glucose from carbon dioxide and water in
the presence of sunlight and chlorophyll, with oxygen as a by-product.
Photosystem:
Photosynthesis pigments are organized in the form of
clusters, called photosystems.
Pigments:
Pigments are the
substances that absorb visible lights.
Pyruvic acid:
Is s molecule with 3-C. it is formed by the breakdown of
glucose.
Reduction:
The gain of electrons is called reduction.
Respiration:
The process in which C-H bonds are broken by
oxidation-reeducation reaction and energy, CO2 and water are produced.
Stroma:
In the chloroplast, grana floot in the inner fluid of
chloroplast called stroma.
Thylakoid:
The inner membrane of chloroplast gives rise to sacs called
thylakoid.
Z-scheme:
The whole series of light reactions is called Z-scheme due
to its Z-shaped flow chart.
NUTRITION
Chapter#08th
Q#1.What are the health risk if we use more saturated fatty
acids in our diet?
Ans: saturated fatty acids can
increase a person cholesterol level. An increased cholesterol level may
eventually result in the clogging of arteries and, ultimately, heart disease.
Q#2.How can the deficiency of
vitamin A cause blindness?
Vitamin A combine with the
protein opsin to form rhodopsin makes it difficult to see in dim light.
Q#3.How will you differentiate between bolus and chyme?
Bolus
During the processes of chewing, lubrication and
semi-digestion, the pieces of food are rolled up by the tongue into small,
slippery, spherical mass called bolus.
|
Chyme
The starch in our bite of bread and the protein
in mutton have been partially digested and has been converted to a soup-like
mixture called chime.
|
Q#4.Which sphincters play role in
the movement of food in and out of stomach?
Cardiac sphincter plays role in
the movement of food in the stomach.
Pyloric sphincter plays role in
the movement of food out of the stomach.
Q#5.Stomach is an organ of the
digestive system, but it also secretes a hormone. What hormone is it and what
function it performs?
Ans: stomach walls release a
hormone called gastrin. This hormone enters blood and is distributed to all
parts of body. In stomach, it has specific effect and stimulates the gastric
glands to secrete more gastric juice.
THE
TERMS TO KNOW
Anemia:
Means’ a lack of blood’. It is a disease in
which numbers of red blood cells is reduced to a level lower than normal.
Amylase:
It is an enzyme which helps in
the partial digestion of starch.
Appendix:
From the blind end of caecum
there arises a non-functional finger like projection called appendix.
Assimilation:
Conversion or incorporation of
absorbed simple food into the complex substances constituting the body.
Balanced diet:
A diet which contain all the
essential nutrients like carbohydrates, fats, proteins, minerals, vitamins in
the correct proportion for the normal growth and development of the body.
Cardiac sphincter:
It is the opening between stomach
and esophagus.
Colon:
Middle portion of large
intestine, from where water is absorbed into blood is called colon.
Constipation:
It is a condition in which a
person experiences hard faeces that are difficult to eliminate.
Diarrhoea:
It is a condition in which
sufferer has frequent watery, loose bowel movements.
Dietary fibers:
Also known as roughage. It is a
part of human food that is indigestible.
Digestion:
Process in which large and
non-diffusible molecules (i.e. Proteins, Polysaccharides and lipids)
Are converted into smaller and diffusible
molecules(i.ie. salts, amino acids, simple sugars, fatty acids and vitamins) is
called digestion.
Duodenum:
Is the first part of small
intestine.it is comprises of the first ten inches (25cm) of the small
intestine. Most of the digestive process occur here.
Emulsification:
The process of breaking down
large droplets of fats into small droplet, of fat is called emulsification.
Epiglottis:
A flap of cartilage which is
responsible for opening and closing of the glottis is called epiglottis.
Famine:
Lack of enough food to feed all
the people living in an area is known as famine.
Fat-soluble vitamins:
Vitamins which are insoluble in
water and soluble in fats are called fat- soluble vitamins.
Example:
Vitamin A, D, E and K are fat
soluble vitamins.
Fertilizer:
Materials which are added to soil
resulted in plants with desirable characteristics (e.g. more fruit, faster
growth, better color, more attractive flowers) are called fertilizers.
Gastric juice:
Secretion of stomach which is
composed of mucous, hydrochloric acid and protein digesting enzymes is called
gastric juice.
Gastrin:
A hormone which enters in blood
and then to all parts of the body including stomach. It affects cells of
gastric glands to secrete more gastric juice.
Goiter:
It is the condition which is
caused by the insufficient of iodine in diet.
If sufficient iodine is not
available in a person’s diet, the thyroid glands becomes enlarged and it
results, in swelling in the neck and the condition is known as goiter.
Ileum:
Last part of small intestine is
called ileum. It is 3.5 meter long.
Intestinal juice:
Is the secretion of intestine
which is secreted by the inner lining of intestine which contain many enzymes
for the complete digestion of all kinds of food.
Jejunum:
Is the second part of small
intestine. It is 2-4 meter long.
Kwashiorkor:
It is the disease caused by
protein deficiency at the age of about 12 months, when breast feeding is
discontinued.
In this disease children may grow
to normal height but are abnormally thin.
Lacteal:
Each villus is richly supplied
with blood capillaries and a vessel of lymphatic system called lacteal.
Lacteal or lymphatic vessel is
present in villi in which fatty acids and glycerol are absorbed. After that
lacteal carries them to the main lymphatic duct.
Laxatives:
Is the medicine used for
treatment of constipation
Example: Paraffin.
Lipase:
It is an enzyme which digest
lipids.
Liver:
It is the largest gland of body.
It is dark reddish organ.
Malnutrition:
Is a term for the condition
caused by an improper or insufficient diet.
Marasmus:
It is the disease caused by protein-energy
malnutrition.
Children with marasmus show poor
growth and look small for their age.
Mineral deficiency disease:
Diseases caused by the deficiency
of minerals are goiter and anemia. Goiter is caused by the deficiency of iodine
and anemia caused by the deficiency of iron.
Nutrition:
The process in which food is
obtained or prepared, absorbed and converted into body substances for growth
and energy, is called nutrition.
Esophagus:
It is the tube like part of
alimentary canal which connects the pharynx to stomach.
Oral cavity:
It is the part of alimentary
canal which is the space behind the mouth.
Over-intake of nutrients:
It is the form of malnutrition in
which more nutrients are taken than the amounts required for normal growth,
development and metabolism.
Pancreas:
It is the leaf shape organ which
secretes pancreatic juice. It contain three enzymes trypsin, pancreatic amylase
and lipase which digest proteins, carbohydrates and lipids respectively.
Pepsin:
It is the activated form of
pepsinogen.
Peristalsis:
The wave like movement of muscles
that pushes food through the digestive system is called peristalsis.
Pepsinogen:
It is a protein digesting enzyme
present in gastric juice.
Pharynx:
It is the second part of
alimentary canal and lies next of oral cavity.
Protein-energy malnutrition:
It refers to inadequate
availability or absorption of energy and protein in the ody.
Pyloric sphincter:
It is the opening between the
stomach and small intestine.
Rectum:
It is the last part of the
alimentary canal in which faeces are temporarily.
Saliva:
It is the secretion of oral
cavity, which is secreted during chewing process of food. Chewing process
stimulates three set of salivary glands to release saliva.
Starvation:
It is the sever reduction in
nutrients and energy intake and is the most horrible effect of malnutrition.
Stomach:
It is the dilated part of
alimentary canal. It is the J-shaped, located in the left of the abdomen, just
beneath the diaphragm.
Swallowing:
Pushing of bolus from esophagus
to pharynx is called swallowing.
During swallowing the bolus is
pushed to the back of the mouth by the tongue and the bolus move to the
pharynx.
Trace pharynx:
Minerals which are required in
very low quantities .i.e. less than 100 mg per day are called trace minerals.
Examples: nickel, chlorine, zinc,
boron etc.
Trypsin:
It is an enzyme of pancreatic
juice secreted by pancreas which digest carbohydrates.
Ulcer:
It is the sore in the gut lining
caused by a gradual breakdown of the tissue by the acidic gastric juice.
Villus:
Circular folds in the inner walls
of the ileum which have numerous finger like projections called villus.
Vitamins:
These are the chemical compounds
that are required in low amounts but are essential for normal growth and
metabolism.
Water soluble vitamins:
These vitamins are soluble in
water.
Examples: vitamin B and Vitamin
C.
Transport
Chapter# 9th
Define the following terms in your own wording:
ABO system:
Systems in which there are four different blood
groups which are distinct from each other on the basis of specific antigens
(antigen A & B) present on the surface RBCs.
Agglutination:
Clumping of blood cells
Agranulocytes:
These are leukocytes with clear cytoplasm. These
includes monocytes and lymphocytes, formed in the lymphoid tissue of lymphatic
system.
Albumin:
A protein without a prosthetic group.
Angina pectoris:
Chest pain which reasons are similar to heart attack.
Anti-A antibody:
A protein produced by lymphocytes that attack
antigen, present in blood group B.
Anti-B antibody:
A protein produced by lymphocytes that attack
antigen, present in blood group A.
Antigen:
Foreign invaders in the body that triggers an immune
response.
Antigen A:
Antigen that present on the surface of RBCs of blood
group A, triggers an immune response.
Antigen B:
Antigen that present on the surface of RBCs of blood
group B, triggers an immune response
Anti-Rh antibody:
An antibody against any Rh antigen, it must be
required & is never natural.
Aorta:
Blood vessel through which oxygenated blood leaves
the human heart.
Aortic arch:
Aorta ascend to form an aortic arch, arteries
emerging from aortic arch supply blood to head, shoulders & arms.
Arteriole:
Arteries
divided into smaller vessels (just like veinlets from veins).
Arteriosclerosis:
Term describing any
hardening of arteries.
Artery:
Blood vessels
which carry blood away from the heart.
Atherosclerosis:
Disease which
referred to as a narrowing of the arteries due to any accumulation of fatty
material, abnormal amounts of smooth muscles, cholesterol or fibrin.
Atrial systole:
The period in
which both atria contract & pump the blood towards ventricles, called
atrial systole.
Atrium:
Upper thin
walled chamber of heart is called atrium.
B lymphocytes:
Lymphocytes
which recognize antigens & synthesize antibodies against them.
Basophils:
Leukocytes
which prevent blood clotting.
Bicuspid valve:
Value with two flaps, present between the opening of left
atrium & left ventricle.
Blood group
system:
Classification
of blood based on the presence or absence of antigens on the surface of red
blood cells.
Capillary:
These are the
smallest blood vessels which are formed by the division of arteriole.
Cardiac cycle:
The alternating
relaxations and contractions make up the cardiac cycle.
Cardiovascular
system:
The system
consisting of the heart, blood vessels & the blood that circulates
throughout the body delivers essential materials to cells & removes waste products.
Cohesion-tension
theory:
According to
this theory, the mechanism by which water is carried upward through the xylem
is transpirational pull.
Coronary artery:
The artery which
supplies blood to the heart muscles is called coronary artery.
Cortex:
External layer of
plants roots consisting of broad zone large, thin walled cells.
Diastole:
Atria & ventricles
relax & blood is filled in atria is called diastole.
Dorsal aorta:
As aorta passes
down through thorax, it becomes dorsal aorta.
Embolus:
An obstruction
in a blood vessel, usually a lodged blood clot.
Endodermis:
A single layer
of cells which surrounds the pericycle layer.
Eosinophil:
A type of
leukocytes that provide defense against parasites.
Erythrocytes:
These are the
type of blood vessels having biconcave shape. These are filled with hemoglobin.
These also known as red blood cells.
Fibrin:
An elastic,
insoluble, whitish protein produced by the action of thrombin on fibrinogen.
Granulocytes:
These are the
leukocytes with granular cytoplasm these includes neutrophils, eosinophil’s
& besophils.
Guard cell:
One of the
paired epidermal that control the opening & closing of a stoma in plant
tissue.
Hemoglobin:
The iron containing
respiratory pigment in red blood cells of vertebrates, consisting of about 6%
haem & 94% globin.
Heart rate:
It is the
number of times the heart beats per minute.
Lenticels:
One of the
small, rocky pores or narrow lines on the surface of stems of woody plants that
allow the interchange of gases between the interior tissue & the
surrounding air.
Leucocytes:
These are
colourless blood cells. They are not confined to blood stream, as they migrate
out the tissue fluid, also called as white blood cells.
Leukemia:
It is
characterized by the appearance of great number of immature & abnormal
white blood cell in the bone marrow & often in the spleen & liver.
Lymphocytes:
These are
the major components of the immune system with large nucleus which fills almost
all of cytoplasm. There are 32% of leukocytes. Their types of B lymphocytes
& T lymphocytes.
Lymphogenous cells:
Cells which
produce lymph or cells in the lymphatics.
Megakaryocytes:
They are
not cells, but are the fragments of large cells of bone marrow.
Monocytes:
These are the
types of WBCs & produce macrophages which engulf germs.
Myocardial
infarction:
Commonly
known as heart attack, medical conditions that occurs when the blood supply to
a part of the heart is interrupted & leads the death of some cells of heart
muscles.
Neutrophils:
Leukocytes
which destroy small particles by phagocytosis.
Pericardial fluid:
The fluid in
the pericardial cavity.
Pericardium:
Heart is
enclosed in a sac called pericardium.
Pericycle:
A plant tissue
characteristics of the roots, located between the endodermis & phloem.
Phloem:
Compound tissues
through which food is transported in a plant.
Plasma:
Plasma is primarily
water in which proteins, salts, metabolites &waters are dissolved.
Platelets:
They are not
cells, but are fragments of large cells of bone marrow, called megakaryocytes.
These help in blood clotting.
Pulmonary artery:
The artery
that carries deoxygenated blood from right ventricle to the lungs for
oxygenation.
Pulmonary
circulation:
The
circulation of blood through the lungs for the purpose of oxygenation & the
release of carbon dioxide.
Pulmonary vein:
A vein that
carries oxygenated blood from the lungs to the left atrium of the heart.
Pulse:
It is the
rhythmic expansion & contraction of an artery as blood is forced through it
by the regular contraction of the heart.
Red blood cells:
A cell in the
blood of vertebrates that transport oxygen & carbon dioxide from & to
the tissues.
In mammals, the red blood cells are biconcave, contains
hemoglobin & lacks a nucleus, also called erythrocytes.
Rh-factors:
Any of
several substances on the surface of red blood cells that induce a strong
antigenic response in individuals lacking the substance.
Rh-blood group system:
In this
system, there are two blood groups i.e. Rh positive & Rh –negative, which
are distinct from each other on the basis of antigens called Rh factors present
on the surface of RBCs.
Root hair:
A thin hair
like outgrowth of an epidermal cell of a plant root that absorbs water &
minerals from the soil.
Semilunar valve:
Valve which
prevents backflow of blood from pulmonary trunk to the right ventricle.
Stoma:
Singular of
stomata, present on the surface of leaves, through which transpiration takes
place.
Systematic
circulation:
Pathway in which
oxygenated blood is carried from heart to the body tissues & in return
deoxygenated blood is carried from the body tissues to the heart is called
systematic circulation.
T lymphocytes:
The recognize
antigens & then combat them in different ways.
Thalassemia:
Also known as
Cooley’s anemia in this disease normal hemoglobin is absent, characterized by severe
anemia, enlargement of heart, liver & spleen & skeletal deformation.
Thrombocytes:
These are not
cells, but are fragments of large cells of bone marrow called megakaryocyte.
These help in blood clotting.
Thrombus:
A blood clot
in a blood vessel (sever form of plaque) that remains at the point of its
formation.
Transpiration:
Loss of water
from plant surface through evaporation.
Transpirational
pull:
Mechanism by which
water along with dissolved material is carried upward through xylem is called
transpirational pull.
Tricuspid valve:
Valve present
the opening between the right atrium & right ventricle, guarded by
tricuspid valve (because it has three flaps).
Vein:
A blood vessel
that carries blood towards the hearti.e. Deoxygenated blood.
Vena cava:
These are two
large veins, called superior & inferior vena cava. Vena cava collects
deoxygenated blood from whole body & pass it to right atrium of heart.
Ventricle:
Lower thick
walled chamber of heart called ventricle. Two ventricles are present in human heart,
right & left ventricle.
Ventricular
systole:
The period
of ventricular contractions is called ventricular systole.
Venule:
Veins divided
into smaller vessels called venules.
White blood cells:
These blood
cells are colourless, they are not confined to blood vessels they are much
larger than (two or three times) the red blood cells.
Wilting:
Plant or its
parts become limp or flaccid. This condition is called wilting.
Xylem:
Compound
tissues which transports water & minerals up a plant.
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