B2 Organisation Flashcards
What is a cell?
The basic building block of all living things
What is a tissue?
A group of similar cells that work together to carry out a special function
What is an organ?
A group of different tissues that work together to carry out a special function
For example the stomach contains glandular, muscular and epithelial tissues
What is an (organ) system?
A group of organs working together to perform specific functions. (Special function)
For example the digestive system contains organs such as the stomach the small intestine and the large intestine
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion
What is the role of the pancreas and the salivary gland in the digestive system?
The pancreas and the salivary gland are glands which produce digestive juices containing enzymes
How is epidermal tissue adapted for its function?
Epidermal tissue covers the entire plant. It has a waxy cuticle which helps reduce water loss from the leaf surface
How is palisade mesothelioma tissue adapted for its function?
Palisade mesophyll tissue contains lots of chloroplasts which allows photosynthesis to progress at a rapid rate
How is spongy mesophyll tissue adapted for its function?
Spongy mesophyll tissue has lots of air spaces which allow gases (including oxygen and carbon dioxide) to diffuse in and out
How is the xylem adapted for its function?
Made up of dead cells which form a continuous hollow tube - allows the movement of water and mineral ions from the roots to the leaves
Strengthened by lignin - makes the vessel strong and waterproof
Has bordered pits - allow minerals to be transported to specific places
How is the phloem adapted for its function?
Made up of elongated living cells
Cells have sieve plates that connect them together cell sap can move through plates into other cells
Sieve tube cells have a few organelles to allow the efficient transport of substances
Give two examples of tissues in plants and animals
Bone, Blood - animals
Xylem, Phloem - plants
Give two examples of organs in plants and animals
Brain, Heart - animals
Root, Leaf - plant
Give two example of systems in plants and animals
Digestive, Reproductive - animals
Vascular system, root - plants
What is the method to test for starch?
1.Place a small amount of food on the spotting tile
2.Add a few drops of iodine solution to the food on the spotting tile
3.Yellow-red iodine solution turns blue-black if starch is present
4.Repeat steps 1-3 for other types of food
5. Record all your results in a results table
What is the method to test for protein?
- Place a small amount of food in a test tube
- Add 1cm^3 of biuret reagent. Alternatively add 1cm^3 of sodium hydroxide solution and then add a few drops of copper sulfate solution
- Blue biuret reagent turns purple if protein is present
- Repeat steps 1-3 for other types of food
- Record all your results in a results table
What is the method to test for sugar?
- Place a small amount of food in a test tube
- Add enough Benedicts solution to cover the food
- Place the test tube in a warm water bath for 10 mins
- Blue Benedict’s solution turns brick red on heating if a sugar such as glucose is present
- Repeat steps 1-4 for other types of food
- Record all your results in a results table
What is the method to test for lipids (fats)?
- Place a small amount of food into a test tube
- Add a few drops of ethanol to the test tube
- Shake the test tube and leave for 1 minute
- Pour the solution into a test tube of water
- Ethanol added to a solution gives a cloudy white layer if lipid is present
How do enzymes work?
The lock and key model is a theory that is used to explain how enzymes work.
The substrate fits into the active site of the enzyme (like a key fits a lock).
The reaction takes place rapidly and the products are released from the surface of the enzyme.
What are the seven nutrients?
Carbohydrates
Protein
Fat
Minerals
Vitamins
Fibre
Water
What is the use of carbohydrates in the body?
To provide energy
What are some good sources of carbohydrates?
Cereals, bread, pasta, rice and potatoes
What are some good sources of protein?
Fish, meat, eggs, beans, pulses and dairy products
What are some good sources of fat?
Butter, oil and nuts
What are some good sources of minerals?
Salt, milk and liver
What are some good sources of vitamins?
Dairy food, fruit, vegetables
What are some good sources of fibre?
Vegetables, bran
What are some good sources of water
Fruit juice, milk, water
What is the use of protein in the body?
For growth and repair
What is the use of fat in the body?
To provide energy. Also to store energy in the body and insulate it against the cold.
What is the use of minerals in the body?
Needed in small amounts to maintain health
What is the use of vitamins in the body?
Needed in small amounts to maintain health
What is the use of fibre in the body?
To provide roughage to help to keep the food moving through the gut
What is the use of water in the body?
Needed for cells and body fluids
How are carbohydrates digested?
Carbohydrases are enzymes that break down carbohydrates
Starch is broken down into the mouth and small intestine by the enzyme AMYLASE
Amylase is produced in the salivary gland
Amylase is also made in the pancreas. No digestion takes place in the pancreas
All enzyme made in the pancreas flow into the small intestine
What is bile?
Bile is green yellow alkaline liquid
Where is bile made?
The liver
Where is bile stored?
It is stored in the gall bladder
What two functions does bile have?
To neutralise hydrochloric acid from the stomach
To emulsify fats to form small droplets which increases the surface area of the fats
What is the composition of blood?
Red blood cells
White blood cells
Platelet
Plasma
What job do red blood cells have?
Transports oxygen around the body
How are red blood cells adapted to their job?
Presence of haemoglobin
Absence if nucleus and other internal structures to make maximum space available for haemoglobin
Biconcave shape allows easy movement of gases in and out of the cell
How are white blood cells adapted to their job?
Some produce antibodies to kill invading microorganisms others can engulf foreign bodies
How are platelets adapted to their job?
It contains a package of chemicals that help blood to clot
How is plasma adapted to its job?
It is largely water which can dissolve a wide range of substances
What job does white blood cells have?
Protects the body against infection
What job does platelets have?
Helps blood to clot at injury sites
What job does plasma have?
Carries substances like sugar, amino acids, urea and carbon dioxide in solution
