7. Cell
An biological unit of all organisms
An autonomous self-replicating unit that may
exist as functional independent unit of life (as
in the case of unicellular organism), or as sub-
unit in a multicellular organism (such as
in plants and animals) that is specialized into
carrying out particular functions towards the
cause of the organism as a whole.
8. Tissue
An aggregate of cells in an organism that have
similar structure and function.
Tissues work in unison to carry out a specific set of functions
form an organ.
The fundamental types
of tissues in animals are epithelial, nerve,connective, muscle, an
d vascular tissues whereas
in plants, they are the meristematic (apical
meristem and cambium), protective
(epidermis andcork), fundamental (parenchyma, collenchyma an
d sclerenchyma) and vascular (xylem and phloem) tissues.
9. Organ
A group of tissues that perform a
specific function or group of functions, and
belongs to an organ system.
11. Arteries
blood vessel carrying blood away from
the heart, walls have smooth muscle and are
innervated by the sympathetic nervous
system. A blood vessel that carries blood from
the heart to the body.
An artery carries large volumes of
oxygenated blood to the major organs of
the body.
12. Veins
Blood vessel that returns blood from the
microvasculature to the heart, walls thinner
and less elastic than those of artery.
13. Capillary
Any one of the minute vessels that connect
the arterioles (thin arteries) and venules
(thin vains), forming anetwork in nearly
all parts of the body.
Their walls act as semipermeable
membranes for the interchange of
various substances, including fluids, betwee
n the blood and tissue fluid
14. Smooth muscle
muscle tissue in vertebrates made up
from long tapering cells that may be
anything from 20-500m long.
smooth muscle is generally involuntary
15. Organism
An individual living thing that
can react to stimuli, reproduce, grow, and m
aintain homeostasis. It can be a
virus, bacterium, protist, fungus, plant or
an animal.
18. Name 4 types of primary tissues and explain briefly their
main role.
Epithelial tissue (skin,digestive tract, reproductive
tract…): Protection, absorption,elimination of
waste product
Connective tissue(blood, bones…): support and
bind other tissues as well as they give shape to
organs and holds them in place.
Muscle tissue (muscles, including cardiac muscle…):
locomotion or movements within internal organs.
Nervous tissue (brain,spinal cord, nerves…)
19. Which is the largest organ in our body and which
is its role.
the skin is often known as "the largest organ of the
human body". This applies to exterior surface, as it
covers the body, appearing to have the largest
surface area of all the organs. Moreover, it applies
to weight, as it weighs more than any single
internal organ, accounting for about 15 percent of
body weight. For the average adult human, the skin
has a surface area of between 1.5-2.0 square
meters, most of it is between 2-3 mm thick. The
average square inch of skin holds 650 sweat
glands, 20 blood vessels, 60,000 melanocytes, and
more than a thousand nerve endings