growth and development
In biology, increase in size and mass during the development of an
organism over a period of time. Growth is often measured as an increase in biomass (mass of organic material, excluding
water) and is associated with cell division by mitosis, subsequent increases in cell size,
and with the differentiation of cells to perform specific functions, for example
red blood cells in mammals and root cells in plants.
organism over a period of time. Growth is often measured as an increase in biomass (mass of organic material, excluding
water) and is associated with cell division by mitosis, subsequent increases in cell size,
and with the differentiation of cells to perform specific functions, for example
red blood cells in mammals and root cells in plants.
protest
the role of the nucleus in directing differentiation - the use of the
cell surface to mediate co-operation between cells and also the first
occurrence of sexual reproduction. During development an organism develops its characteristic shape - a process
called Morphogenesis.
cell surface to mediate co-operation between cells and also the first
occurrence of sexual reproduction. During development an organism develops its characteristic shape - a process
called Morphogenesis.
Annelid Worms
Annelid eggs, like those of flatworms and mollusks, exhibit spiral, or
determinate, cleavage, so called because early differentiation of various
regions occurs; in indeterminate cleavage (in echinoderm and chordate eggs), early differentiation does not
occur.
In annelids, the first four cells (blastomeres) give rise, by alternating
clockwise and counterclockwise divisions, to a cap of smaller cells, called micromeres, at one end of the egg and a cap
of larger cells, called macromeres, at
the other end.
determinate, cleavage, so called because early differentiation of various
regions occurs; in indeterminate cleavage (in echinoderm and chordate eggs), early differentiation does not
occur.
In annelids, the first four cells (blastomeres) give rise, by alternating
clockwise and counterclockwise divisions, to a cap of smaller cells, called micromeres, at one end of the egg and a cap
of larger cells, called macromeres, at
the other end.
insects
Insects and mites belong to a large group of animals known as arthropods.
Several characteristics differentiate insects from other arthropods. The body is
segmented, and the segments are grouped into three sections: head, thorax and
abdomen. The eyes, antennae and mouthparts are on the head, and the legs and
wings are on the thorax.
Several characteristics differentiate insects from other arthropods. The body is
segmented, and the segments are grouped into three sections: head, thorax and
abdomen. The eyes, antennae and mouthparts are on the head, and the legs and
wings are on the thorax.
Amphibians
The complex life history of many amphibians has been designed to take advantage
of the resources of two completely different habitats. The aquatic free-living
amphibian larva is different from the terrestrial adult regarding morphology,
physiology and behavioural patterns. Therefore, in the life-time of an
individual amphibian, two discontinuous growth stanzas are exhibited. The
sigmoid growth model fits well with both stanzas.
of the resources of two completely different habitats. The aquatic free-living
amphibian larva is different from the terrestrial adult regarding morphology,
physiology and behavioural patterns. Therefore, in the life-time of an
individual amphibian, two discontinuous growth stanzas are exhibited. The
sigmoid growth model fits well with both stanzas.
mammals
Mammals are born from live birth. Mammals also require their mother's milk for
development and growth. Once a mammal has fully developped, it is capable of
living on its own.
development and growth. Once a mammal has fully developped, it is capable of
living on its own.
Nonvascular Plants
gymnosperm
angiosperm
Growth is the process by which a plant increases in the
number and size of leaves and stems. The result of plant growth is forage
production and the amount harvested by animal or machine is forage yield. The
growth of both plants and animals requires energy. Animals get their energy by
digesting the plants they eat. Plants get their energy from the sun through
photosynthesis. Photosynthesis is the process where the green pigment in the
plant's leaf (chlorophyll) absorbs energy from sunlight and, using this energy,
water, and carbon dioxide, produces oxygen and simple sugars. The plant then
uses these sugars to make more complex sugars and starches for storage as
energy reserves, to make cellulose and hemicellulose for cell walls or with
nitrogen, to make proteins. How the plant uses its energy depends on the
developmental stage of the plant and on environmental conditions.
number and size of leaves and stems. The result of plant growth is forage
production and the amount harvested by animal or machine is forage yield. The
growth of both plants and animals requires energy. Animals get their energy by
digesting the plants they eat. Plants get their energy from the sun through
photosynthesis. Photosynthesis is the process where the green pigment in the
plant's leaf (chlorophyll) absorbs energy from sunlight and, using this energy,
water, and carbon dioxide, produces oxygen and simple sugars. The plant then
uses these sugars to make more complex sugars and starches for storage as
energy reserves, to make cellulose and hemicellulose for cell walls or with
nitrogen, to make proteins. How the plant uses its energy depends on the
developmental stage of the plant and on environmental conditions.