biology notes

HEARTBEAT ➤ The alternating  relaxations and contractions make up the cardiac cycle and one   complete  cardiac cycle makes one heartbeat.and in other words, one complete pulsation  of the heart  is called heartbeat. It is the complete regular movement movement of our  heart as it passes  blood around your body. STEPS OF CARDIAC CYCLE ➤ C omplete cardiac cycle consist of the following steps .   CARDIAC DIASTOLE ➤ Atria and ventricles relax and blood is filled in atria. this period is called cardiac   diastole.  In short, it is the period of relaxation of heart muscles.In one complete heartbeat,   diastole  lasts about 0.4 seconds. ATRIAL SYSTOLE ➤ It is the last phase in diastole during which the ventricular filling is  competed.    Immediately  after their  filling, both atria contracts and pump blood towards ventricles.   This period in  cardiac cycle is called  atrial systole.In o...

what is guttation  

OSMOREGULATION   THERMOREGULATION

  HOMEOSTASIS

CELL DEFINE CELL  

  SPINAL CORD ★ THE SPINAL CORD IS IN FACT A TUBULAR BUNDLE OF NERVES.   STARTS FROM; ★ IT STARTS FROM BRAIN STEM AND EXTENDS TO LOWER BACK. SPINAL CORD IS THE    CONTINUATION OF MEDULLA OBLONGATA. MEDULLA OBLONGATA NARROWS DOWN    INTO AN OVAL SHAPED HOLLOW CYLINDER, THE SPINAL CORD, RUNNING THROUGH     THE VERTEBRAL COLUMN. CONSIST OF; ★ IT CONSIST OF A VERY LARGE NUMBER OF NEURONS. THE CELL-FIBRES AND BODIES     OF WHICH ARE ARRANGED IN A DEFINITE PATTERN. COVERED BY; ★ LIKE BRAIN, SPINAL CORD IS ALSO COVERED BY  MENINGES. THE VERTEBRAL    COLUMN SURROUNDS AND PROTECTS SPINAL CORD. SIZE OF SPINAL CORD; ★ SPINAL CORD IS ROUGHLY 40cm LONG AND ABOUT AS WIDE AS YOUR THUMB FOR    MOST OF ITS LENGTH. REGIONS OF SPINAL CORD; OUTER REGION; ★ THE OUTER REGION OF SPINAL CORD IS MADE OF WHITE MATTER . ★ CONTAINING MYELINATED AXONS. CENTRAL REGION; ★ THE CENTRAL REGION IS BUTTERFLY SHAPED THAT SURROUNDS THE CEN...

NUTRIENTS  NUTRITION    

 DIVISION OF ORGANISMS ORGANISMS CAN BE DIVIDED INTO TWO CLASSES ON THE BASIS OF THEIR METHODS  OF NUTRITION; AUTOTROPHIC ORGANISMS   HETROTROPHIC ORGANISMS  

 BIODIVERSITY SPECIES    

★★★ CARBOHYDRATES ★★★  MEANS OF; ★ THE WORD CARBOHYDRATES LITERALLY MEANS ' HYDRATED CARBON '. COMPOSED OF; ★ THEY ARE COMPOSED OF CARBON, HYDROGEN AND OXYGEN AND THE RATIO OF    OXYGEN AND HYDROGEN IS THE SAME AS IN WATER. GENERAL FORMULA; ★ THEIR GENERAL FORMULA IS Cx(H2O)y WHERE (x) IS THE WHOLE NUMBER FROM    THREE TO MANY THOUSANDS WHEREAS y MAY BE THE SAME OR DIFFERENT WHOLE    NUMBER. CHEMICALLY; ★ CHEMICALLY CARBOHYDRATES ARE DEFINED AS POLYHYDROXY ALDEHYDES OR  KETONES, OR COMPLEX SUBSTANCES WHICH ON HYDROLYSIS YIELD POLYHYDROXY ALDEHYDE OR KETONE SUB-UNITS. WHAT IS HYDROLYSIS? ★ HYDROLYSIS INVOLVES THE BREAK DOWN OF LARGE MOLECULES INTO SMALLER    ONES UTILIZING WATER MOLECULES. SOURCE OF CARBOHYDRATES; ★ THE SOURCE OF CARBOHYDRATES ARE GREEN PLANTS. THESE ARE THE PRIMARY      PRODUCTS PHOTOSYNTHESIS. OTHER COMPOUNDS OF PLANTS ARE PRODUCED            FROM CARBOHYDRATES BY VARIOUS CHE...

CELL THEORY  

FLUID MOSAIC MODEL  

OLFACTORY BULBS  

What is plasmodesmata Plasmodesmata (singular ; plasmodesma) are microscopic channels which traverse the cell wlls of plant cells, and some algal cells, enabling transport and communication between them.  There are two forms of plasmodesmata: primary plasmodesmata, which are formed during cell division, and secondary plasmodesmata, which can form between mature cells. Similar structures called gap junctions, membrane nanotubes, interconnect animal cells, and stomules form between plastids in plant cells. A typical plant cell may have between 1,000 and 100,000 plasmodesmata connecting it with adjacent cells.   Plasmodesmata Structure Plasmodesmata is a tube linking one cell to another. Surrounding the open space of the tube is a membrane and running in the center is the desmotubule, which consists of tightly packed endoplasmic reticulum (ER). The ER is continuous between the two cells. Between the desmotubule and the membrane is the cytoplasmic sleeve, where most transfer ...

HIPPOCAMPUS  

✦✦✦BRAIN ✦✦✦ ★ IN ANIMALS, ALL LIFE ACTIVITIES ARE UNDER THE CONTROL OF BRAIN. CRANIUM; ★ BRAIN IS SITUATED INSIDE A BONY CRANIUM (PART OF SKULL) . MENINGES; ★ INSIDE CRANIUM, BRAIN IS COVERED BY THREE LAYERS CALLED MENINGES.  FUNCTION OF MENINGES; ★ MENINGES PROTECT BRAIN AND ALSO PROVIDE NUTRIENTS AND OXYGEN TO     BRAIN TISSUE THROUGH THEIR CAPILLARIES. FLUID-FILLED VENTRICLES; ★ THE BRAIN CONTAINS FLUID-FILLED VENTRICLES THAT ARE CONTINUOUS WITH    THE CENTRAL CANAL OF SPINAL CORD. CEREBROSPINAL FLUID; ★ FLUID WITHIN VENTRICLES AND CENTRAL CANAL IS CALLED CEREBROSPINAL     FLUID (CSF) . DIVISIONS OF BRAIN; THE BRAIN CAN BE DIVIDED INTO; ★ FOREBRAIN ★ MIDBRAIN  ★ HINDBRAIN FURTHER DIVISION OF FOREBRAIN;  FOREBRAIN IS FURTHER DIVIDED INTO THREE FUNCTIONAL PARTS THE  ★ THALAMUS, ★ THE LIMBIC SYSTEM  ★ THE CEREBRUM.  THALAMUS; ★ THALAMUS CARRIES SENSORY INFORMATION TO THE LIMBIC SYSTEM AND   CEREBRUM. THE INFOR...

  ENZYMES METABOLISM CO-FACTOR   ACTIVE SITE & SUBSTRATE ACTIVATOR & PROSTHETIC GROUP COENZYME

 APOENZYME & HOLOENZYME REGIONS OF ACTIVE SITE BINDING SITE & CATALYTIC SITE LOCK & KEY MODEL EXAMPLE INDUCED-FIT-MODEL ENZYME REACTION