Seen from the front, the head of the honeybee has a triangular shape, the head of the drone it is more round. On the head are the eyes, antennae and mouth parts. Important glands are located in the head and the main center of the nervous system: a nerve bud that serves as a brain.
Ganglia are part of the peripheral nervous system. The peripheral nervous system includes all nerves outside the central nervous system (bundles of long nerve shoots with supporting cells) and small centers of nerve cells the ganglia.
A ganglion is a combination of mainly cell bodies (ganglion cells) with the nucleus of the nerve cell surrounded by cytoplasm without further shoots. This cell body with the nucleus as its center forms the metabolic center of the cell and is sensitive to stimuli. Ganglia function as switching stations for nerve impulses.
The southern green stinkbug (Nezara viridula) is a relatively new pest that originates from Ethiopia. The pest has a large number of host plants, but in horticulture this bug is mainly found in bell pepper cultivation. In the first instance, in The Netherlands, the southern green stink bug was only spotted at the end of the summer, but the bug has also shown itself earlier in the season in recent years.
Females lay around 30 to 130 eggs at a time. They do this in "glued together", yellow and white clusters at the bottom of the leaf. If they are just laid, they look like little pearls. Depending on the temperature, the eggs hatch after 4 days to 3 weeks and the empty eggs remain on the leaf. The nymphs initially stay together and do not yet affect the plant. They then go through different stages, each time shedding their skin, with each stage having a different appearance. In the fifth stage, the bugs begin to spread over the plant and eat it.
Sundew or Drosera forms perfect rosettes to the ground and has red tentacles with a sticky, glittering droplet which is secreted by a gland. The flower owes its name to this. Small animals get stuck in the drop and are pushed by the moving tentacles to the leaf surface where they are digested.
Prepared slide by Lieder
The disease owes its name to the Austrian doctor Otto Kahler, who described the disease as one of the first. Kahler's disease, also called multiple myeloma, is a disease of the bone marrow caused by an uncontrolled proliferation of a certain type of white blood cells: plasma cells (also called plasmocytes). Plasma cells are responsible for the formation of antibodies under normal conditions.
The bone marrow is a spongy substance located in the interior of bones, especially the pelvis, sternum, ribs and vertebrae. Bone marrow plays a role in forming bones, but also in forming the cells of the blood: white blood cells (leucocytes), red blood cells (erythrocytes) and platelets (thrombocytes). The disease develops in one abnormal plasma cell, which divides uncontrollably and whose offspring also divides uncontrollably. Since they are all related, they only synthesize one specific type of antibody (or part of it). Since antibodies are proteins, the antibody produced is referred to as the "M protein" (from Myeloma protein). The name paraprotein is also commonly used for the M protein. When a specific piece (called “light chain”) of a paraprotein is found in the urine (or blood serum), it is called the Bence-Jones protein.
Tempskya is an extinct genus of tree-shaped ferns, the fossils of which have so far only been found in Cretaceous layers. The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic period 145 million years ago to the beginning of the Paleogene period 66 million years ago.
In the video you will find some algae found in fens in the ‘Wortel Kolonie’ located in Belgium. The ‘Wortel Kolonie’ is a beautiful protected nature reserve with a complex of buildings that served as an asylum for vagrants long time ago. (Here you will find the information in Dutch, English, French and German).
This nature reserve contains a few shallow fens. On a summer day in July, some water samples were taken from two fens using a trawl net with a mesh size of 30 microns. Without examining these samples in depth, more than fifty different organisms, phyto- and zooplankton, were found. Only a few of them are shown in the video. In one of the algae we see a oogonium.
The names of the organisms in the video are deliberately omitted here, to give hydrobiology enthusiasts the opportunity to identify the organisms themselves.
The whelk or Buccinum undatum (Linnaeus, 1758) belongs to the snails (Gastropoda).
The whelk is a large, thick predatory snail with 7 or 8 turns. A deep seam runs between the turns. The mouth opening takes up almost half of the shell and ends in a sipho. On the surface there are horizontal ribs and clear vertical growth lines. Often there are also vertical ribs at the top of the shell. It grows up to 11 cm high and 7 cm wide. The whelk has yellowish-white with dark spots. Whelks washed ashore are often dark blue, because they have been lying on the bottom of the sea for a long time.
Vorticella is a genus of single celled organisms living in both marine- and freshwater habitats. The members of the vorticella genus are commonly referred to as bell animalcules because of their shape. The thing that makes bell animalcules unique are their long stalks which they use to attach themselves to a substrate, which could be things like rocks, twigs and even small animals. The stalks of vorticella resemble our muscle fibers but are able to contract a lot faster than our muscles are. If the cell gets disturbed, it’s able to contract the stalk with an impressive speed of up to 6 meters per second as a defence mechanism to get away from danger or possibly scare predators away.
The peregrine falcon is one of the fastest birds in the sky. During level flight, with motion generated by wing-beats alone, they can reach speeds between 60-100 km/h. This is one of the fastest known speeds for level flight.
Coleps is a barrel-shaped ciliate, notable for its regularly arranged ectoplasmic shields, or platelets, of calcium carbonate. The covering with the scales is sometimes completely or partly absent immediately after an amitotic division (direct cleavage of the nucleus without the formation of mitoses). This is clearly visible in the accompanying video. Cell division took approximately 45 minutes. The color of the cell is usually brown and is less determined by the color of the food consumed than with other ciliates.
Like many other crustaceans, water fleas are very sensitive to light. They have a light-sensitive organ, also called Ocellus, with which they can swim in the direction of the light.
The yak is a bovine species, that lives amongst others in Tibet. They graze in the cool higher part of mountainous areas. Yaks are not adapted to living in hot climates. The main raw material produced by the yaks is wool, existing of tail hair and long hair along the yak belly. Yak shearing takes place in the spring, which is a difficult action because of the furious personality of this animal.
These are free-swimming larvae of so called phantom midges or lake flies and inhabit the area between the bottom and the surface of ditches. They are hunters of small crustaceans such as daphnia and cyclops. These animals are practically transparent, and are therefore also called glass larvae. (For the sake of clarity, the preparation has been stained)
With the help of air bubbles in the fore and abdomen, they remain in balance with the water and float unseen through ditches, swimming with leaping movements. They grow to about 1 cm to 1.5 cm long. When two larvae meet each other, a tumble around each other occurs.
The black alder - Alnus glutinosa - lives in symbiosis with bacteria from the actinomycetes group. These are capable of withdrawing nitrogen from the atmosphere. Through this partnership, the alder, despite its relatively high nutritional requirements, can colonize nitrogen-poor locations.
For this Amoeba see the excellent website of the world famous amoeba specialist Ferry Siemensma.
"DIAGNOSIS: Amoebae partially enclosed within a flexible cuticle or wall (tectum) usually covered with microscales (Cochliopodium) or with a dorsal fibrous cell coat without scales (Ovalopodium). The covering is open along the region of attachment to the substratum; with no well-defined aperture.
Amoebae in this family have been classified as testate amoebae by Page (1987b) but are included in this chapter because they resemble euamoebae at the light microscope level. Typically they have a distinct hyaline zone often with short subpseudopodia, and a prominent central granular hump."
For the photo, a tiny grain of iodine was applied over an object slide with a cover slip on top. After gently melting it over a spirit flame and then solidifying, a crystal structure appears, which can be seen with the help of polarization.
The photos show various parts of the rat's eye. There are many similarities between the eyes of the rat and those of humans, but also some striking differences. A few of these are mentioned here.
