Topic 5 Functioning Systems Flashcards
What is a specialised cell?
A cell in a multicellular organism that specialises in form and function so that they perform various functions that serve the needs of the whole organism.
How do specialised cells compare with cells of unicellular organisms?
A specialised cell of a multicellular organism performs fewer functions but has lost the ability for independent living. In contrast to the single cell of a unicellular organism that can perform all the functions needed to stay alive.
What are the levels of organisation?
Cell-basic structural and functional unit
Tissue-group of similar cells carrying out same functions
Organ-groups of tissues working together for the same functions
System-groups of organs serving a particular function
What are the specialised plant cells?
Guard cells Pollen grains Palisade parenchyma Epidermal cell Vessel element Sieve tube cell Root hair cell
What is the function of a guard cell?
A pair of curved cells that surround a stoma, becoming larger or smaller according to air pressure within the cells
What is the function of a pollen grain?
Houses gametes, sperm for sexual reproduction
What is the function of palisade parenchyma cells?
Photosynthetic cells of the leaf
What is the function of the epidermal cell?
Top layer of a leaf, prevent water loss
What is the function of a vessel element?
Move water and ions from the root to the leaves where photosynthesis occurs.
What is the function of a sieve tube cell?
Responsible for transport of sugar
What is the function of a root hair cell?
Facilitates the uptake of water and ions.
What are the specialised animal cells?
White blood cells Red blood cells Skeletal muscle cell Egg cell Sperm cell Motor neurone cell Pancreatic cell Epithelial cell
What is the function of white blood cells?
Cell of the immune system that are involved in protecting the body against infections diseases and foreign invaders.
What is the function of a red blood cell?
Transport oxygen, remove carbon dioxide from the body transporting it to the lungs for exhalation
What is the function of an egg cell?
To join with male cells and provide food for the new cells to be formed.
What is the function of a skeletal muscle cell?
Specialised for voluntary movement
What is the function of a motor neurone cell?
To carry nerve impulses to different parts of the body.
What is the function of a sperm cell?
Fertilises female eggs
What’s the function of a pancreatic cell?
Synthesise and release digestive enzymes
What is excretion?
The removal of unwanted, excess or toxic metabolic products from an organism.
Why is it important to eliminate wastes from the body?
They can be harmful or will interfere with normal metabolism if they build up.
What are some examples of wastes?
Urea, ammonia, excess water and carbon dioxide
What is the major source of n wastes for mammals?
Dietary proteins
How are nitrogenous wastes dealt with in the human body?
The proteins in food are broken down into their amino acid subunits through indigestion.
After absorption into the body, these amino acids are used to build a mammals on proteins as part of growth and repair.
What happens to excess amino acids?
They cannot be stored and are transported to the liver where they are dissected into two parts in a process called deamination.
What happens in deamination?
The n containing part of each amino acid is removed as ammonia (nh3). The remaining part, known as a carbon skeleton is used as a source of energy in aerobic respiration or conversion to glucose. The ammonia that is produced by the deamination in liver cells is immediately converted to urea and is the form in which most n wastes of mammals are excreted.
Why is ammonia converted to urea?
Because it is less toxic that ammonia and can therefore be stored in the body until it is convenient to eliminate it.
What are other sources of n wastes in mammals?
Other n wastes come from the breakdown of nucleic acids into their nucleotide subunits and from metabolic activity of skeletal muscle that generates creatine and its derivative, creatine
What are the major organs of the urinary system?
Bladder Liver Kidney Uretha Ureter Aorta Vena cave
What are the three functions of the kidney?
- Filter wastes from the blood such as urea, excess water, ions toxins
- Excrete hormones and other substances (vitamins for eg) that would otherwise build up in the blood stream.
- Maintain the correct balance of water and ions which help maintain the ph of blood and suitable blood pressure.
What is the function of the bladder?
A hollow organ that stores urine until it is excreted.
What is the function of the kidney?
Two organs that take waste from the blood and produce urine.
What is the function of the ureter?
Two tubes, each of which carries urine from the kidney to the bladder.
What is the function of the urethra
The tube that carries urine from the bladder to the outside of the body.
What is the function of the aorta?
Transports blood to the kidney
What is the function of the vena cava?
Transport blood away from the kidney.
What is the function and location of the glomerulus?
Function: network of capillaries carrying blood under high pressure in bowmans capsule of the nephron.
Location: cortex
What is the function and location of Bowman’s capsule?
Function: collects primary filtrate (nitrogenous wastes and other small soluble molecules but not cells) forced by high pressure
Location: cortex
What is the function and location of the proximal tubule?
Function: site of selective reabsorption of useful substances, such as water, glucose amino acids, salts.
Location: cortex
What is the function and location of the loop of henle?
Function: active concentration is used to establish salt concentration to enhance water reabsorption.
Location: medulla
What is the function and location of the distal tubule?
Function: tubular reabsorption of substances such as sodium by active transport (water follows by osmosis)
Location: cortex
What is the function and location of the collecting duct?
Function: reabsorption of water by osmosis so that concentrated urine leaves the nephron
Location: cortex and medulla
What are the three steps in which urine is produced?
Filtration
Reabsorption
Secretion
Where does filtration occur in the nephron?
Glomerulus
Bowman’s capsule
What happens during filtration?
Blood in the glomerular capillaries is under high pressure. Substances are forced through the capillary walls of the glomerulus and through the inner walls of bow,and capsule. About one fifth of the plasma that passes through the glomerulus is filtered through the capsule into the tubule.
What substances can be removed or reabsorbed in filtration?
Water and n wastes are removed (urea) nutrients such as glucose, amino acids, drugs, salts, become part of the filtrate. Large proteins and blood cells do not make it through the glomerulus and inner walls of Bowman’s capsule.