Topic Four - Functioning Systems Flashcards
Cells
Basic units of life that make up all living organisms
Tissues
Groups of similar cells working together to perform a specific function
Organs
Structures made up of different tissues working together to perform a specific function
Systems
Groups of organs working together to perform a specific function in the body
Plant Cells
Cells that make up plants and are organised into dermal, vascular, and ground tissues
Vascular Plants
Plants with vascular tissue that transport water and minerals throughout the plant
Non-vascular Plants
Plants without vascular tissue and only require simplified tissues to function
Dermal Tissue
Single layer of cells covering the outside of a plant that secretes a waxy film to protect the plant
Ground Tissue
Tissue that makes up the majority of the interior of a plant and carries out metabolic functions
Vascular Tissue
Tissue that carries water and nutrients through the ground tissue of vascular plants
Root System
Part of the plant system that is underground and absorbs water and nutrients from the soil
Shoot System
Part of the plant system above ground that includes leaves, stems, flowers, and fruit
Animal Cells
Cells that make up animals and are organised into muscle, nerve, connective, and epithelial tissues
Muscle Tissue
Tissue that contracts and moves the body
Nerve tissue
Tissue that carries electrical signals throughout the body
Connective Tissue
Tissue that supports and connects different parts of the body
Epithelial Tissue
Tissue that covers and lines surfaces of the body
Animal Organs
Structures made up of different tissues working together to perform a specific function in animals
Digestive System
System in animals that breaks down food and absorbs nutrients
Respiratory System
System in animals that exchanges gases between the body and the environment
Immune System
System in animals that defends against infections and diseases
What is digestion?
Digestion is the breakdown of large food molecules into smaller forms that can cross plasma membranes and be used by the body.
What is the digestive system?
The digestive system is a system of specialised tissues and organs responsible for digestion.
What do animals consume?
Animals are heterotrophs that have to consume other organisms or their products to obtain organic molecules.
What do organic molecules provide?
Organic molecules provide chemical energy to the animal to be able to live, survive, and reproduce. They include carbohydrates, lipids, proteins, vitamins, and minerals.
What are the two methods of food digestion?
Physical (or mechanical) digestion
Chemical digestion
What is physical digestion?
Physical digestion describes the processes whereby the mechanical movement of organs and tissues causes the breakdown of food into smaller pieces.
What are the movements involved in physical digestion?
Chewing, muscle contractions, and the stirring of food and digestive juices by muscle movements.
What is chemical digestion?
Food pieces undergo chemical digestion by enzymes and stomach acid, producing smaller molecules that are capable of being absorbed.
What are the three major types of digestive enzyme?
Amylases (carbohydrates), proteases (proteins), and lipases (lipids).
What are the four steps of digestion?
Ingestion
Digestion
Absorption
Elimination/egestion
What happens during ingestion?
Food is taken into the body. The teeth physically break down food into smaller pieces, whilst enzymes in the saliva chemically break down the food pieces into a soft mass that can be swallowed.
What happens during digestion?
Occurs along the digestive tract. The soft mass travels from the mouth into the body of the organism and continues to be broken down both physically and chemically by a variety of organs.
What happens during absorption?
Small food molecules are absorbed across the plasma membrane of cells in the digestive tract into the bloodstream. The energy from food is ready to be used by the body.
What happens during elimination/egestion?
Undigested food is eliminated from the body as faeces.
What are the cells, tissues, and organs of the human digestive system?
Mouth
Pharynx
Oesophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
What are the differences in the digestive system of herbivores, omnivores, and carnivores?
Omnivores consume a wide variety of food types and have a combination of both sharp and blunt teeth.
Carnivores have sharp teeth, including large canine teeth.
Herbivores have much longer digestive systems and far greater concentrations of gut microbiota compared to carnivores and omnivores.
What are the functions of water in plants?
Water is involved in metabolic reactions, nutrient transportation, overheating prevention, maintaining cell tonicity, and preventing wilting and dehydration in plants.
Why can’t simple plants transport water passively?
Simple plants can passively transport water, nutrients, and waste due to a high surface area to volume ratio, and substances diffusing across small distances.
What are the two main types of vascular tissues in plants?
The two main types of vascular tissues in plants are xylem and phloem.
What are vascular bundles?
Vascular bundles are groups of xylem and phloem tissues that run through the stem, root, or leaves of vascular plants.
What are the functions of the root system in plants?
The root system provides stability, support, and absorption of water and minerals from the soil.
What are the two different pathways of water and nutrient absorption in roots?
The two different pathways of water and nutrient absorption in roots are extracellular and cytoplasmic pathways.
What is the composition of xylem?
Xylem is composed of long, skinny tubes that run from the roots to the shoots of plants, made from vessel elements and tracheids, which have hollow cells, lignified cells, and pits between them.
What is transpiration?
Transpiration is the passive process of water movement up the xylem and its exit via the stomata, helping plants regulate heat and water balance, distribute nutrients throughout the plant, and prevent wilting and cell damage.
What are the factors that affect transpiration?
The factors that affect transpiration are temperature, light, and humidity.
Xylem
Transports water and minerals from roots to the rest of the plant
Composed of specialized cells called tracheids and vessel elements
Movement is driven by transpiration and cohesion-tension mechanisms
Phloem
Transports sugars, amino acids, and other organic compounds throughout the plant
Composed of specialized cells called sieve elements and companion cells
Movement is driven by pressure flow mechanisms
Extracellular Pathway
Refers to the movement of materials outside of cells
Can occur through diffusion, osmosis, or active transport
Plays a role in maintaining homeostasis and exchanging materials between cells and their environment
Cytoplasmic Pathway:
Refers to the movement of materials within cells
Can occur through diffusion, facilitated diffusion, or active transport
Plays a role in cellular processes such as metabolism, signaling, and organelle transport.
Transpiration
The passive process of water movement up the xylem and its exit via the stomata.
Factors affecting transpiration
Temperature, light, humidity, wind, and water availability can affect the rate of transpiration.
Guard cells
Two specialized cells surrounding the stomatal pore that regulate transpiration by opening and closing the stomata.
Open stomata
When stomata are open, water vapour can freely leave the leaf as part of transpiration, CO2 can enter the leaf, and O2 can exit the leaf.
Closed stomata
When stomata are closed, gases cannot freely leave or enter a leaf, thereby reducing the rate of photosynthesis, transpiration, and water loss.
Turgid guard cells
Guard cells that have absorbed water and become swollen, causing the stomata to open and increase the rate of transpiration.
Flaccid guard cells
Guard cells that have lost water and become limp, causing the stomata to close and reduce the rate of transpiration.
Companion cells
Companion cells provide metabolic support to sieve cells, as they have a nucleus and other organelles and are capable of carrying out essential cellular processes such as respiration and protein synthesis.
Sieve cells
Sieve cells have thin walls and are arranged end to end to form sieve tubes, which are the main conduits for the transport of photosynthates in the phloem.
Sieve cells lack a nucleus and other organelles, but they contain numerous small pores known as sieve plates, which allow for the flow of fluids between adjacent cells.
Translocation
Translocation is the process by which photosynthates (sugars and other organic compounds) are transported through the phloem from source tissues (such as leaves) to sink tissues (such as roots or developing fruits).
What is the excretory system?
The excretory system is a specialized system in the human body that removes waste substances and regulates water and ion concentrations.
What are the organs and tissues involved in the excretory system?
The excretory system comprises a number of organs and tissues, including the lungs, liver, kidneys, skin, and bladder.
What are the waste materials that are accumulated in the human body during cellular processes?
The waste materials that are accumulated in the human body during cellular processes include carbon dioxide from respiration, toxins, and nitrogenous waste from protein breakdown.
How are excess amino acids removed from the body?
In humans, the excess amino acids are transported from the small intestine of the digestive system to the liver. In the liver, the amine group (NH2) of amino acids is converted to ammonia (NH3) in a process known as deamination. Ammonia is toxic to cells, so it is further broken down to less toxic urea. Urea can be safely transported in the bloodstream.
What is the role of the kidneys in the excretory system?
The role of the kidneys is to filter blood, reabsorb the useful substances within the filtrate, and secrete the unwanted ones.
Where are the kidneys located?
In humans, the kidneys are two bean-shaped organs located in the upper back on either side of the spinal column.
What is the functional unit of a kidney?
A kidney contains millions of nephrons, which are the functional unit of a kidney.
What are the afferent and efferent capillaries in the kidney?
The capillaries that deliver blood to nephrons are called the afferent capillaries, while the capillaries that take blood away from nephrons are called the efferent capillaries.
How do the kidneys regulate water balance?
If you drink lots of water, then the distal convoluted tubule and collecting duct do not reabsorb much water. Conversely, if you lose lots of water or don’t drink enough, the distal convoluted tubule and collecting duct reabsorb lots of water into capillaries. This increases the concentration of urea in the urine. Because they filter the blood and dictate how much water is present in urine, kidneys also play a role in regulating blood pressure and blood pH.
What are the organs of the urinary tract?
The organs of the urinary tract are the kidneys, ureters, bladder, and urethra.
What are the functions of the bladder and urethra in the excretory system?
After being produced in the kidneys, urine leaves each kidney via a tube known as a ureter. The ureters carry urine to the bladder, where it remains until it is ready to be emptied. Upon being emptied, urine exits the body via the urethra.
What are the additional organs of the excretory system?
When cells undergo cellular respiration, carbon dioxide and water are produced. The water is incorporated into body fluids, and the carbon dioxide is released from the cells to the lungs, and is exhaled into the surrounding environment of the organism. A small amount of nitrogenous waste and ions are removed from the body via sweating. The liver can also be considered an organ of the excretory system as it breaks down toxins and other waste materials in the blood that are then carried through to the urinary tract and excreted. Sometimes waste material is released into the digestive tract and comes out in faeces. Because of this, the digestive tract can also
Signalling molecules
Special chemicals used by cells to communicate with each other. They can instruct cells to alter gene expression, open and close protein channels, release other signalling molecules, or even die.
Hormones
One of the most important groups of signalling molecules that influence growth, metabolism, and the maintenance of a stable internal environment. Hormones also play a crucial role in sexual development and maturity.
Endocrine System
The collection of glands in an organism responsible for producing hormones.
Target cells
Cells that have specific receptors that can bind to hormones, allowing the hormone to elicit a response in the cell.
Hormonal communication
A specific form of communication where hormones only influence cells with specific receptors.
Bloodstream
The system of vessels and tissues responsible for transporting blood throughout the body. Hormones produced by the endocrine system are transported through the bloodstream.
Major components of the endocrine system
The glands and organs responsible for producing hormones, including the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, and reproductive organs.
Summary of the endocrine system
The endocrine system is responsible for producing hormones that allow cells to communicate and instruct a wide range of processes throughout the body. Hormones are transported via the bloodstream and only influence cells with specific receptors. The major components of the endocrine system include the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, and reproductive organs.
