Biology junior cert Flashcards
What were the characteristics of living things?
● Movement - walking, running, flying
● Respiration - the releases of energy from food
● Sensitivity - the way living things respond to their environment
● Nutrition - the way a living thing gets its food
● Excretion - the removal of metabolic waste from the body
● Reproduction - the formation of new individuals
● Growth - organisms get bigger as cells divide
What are the characteristics of animal cells?
● Cell membrane - holds in the contents of the cell and controls what substances enter and leave the cell
● Cytoplasm - a watery fluid in which many cell reactions take place
● Nucleus - controls the activities of the cell and contains genetic information
(chromosomes)
What are the characteristics plant cells?
● Cell wall - provides support and structure to plant cells
● Cell membrane
● Cytoplasm
● Chloroplasts - these contain chlorophyll which makes food for plant cells in
photosynthesis
● Vacuole - stores food, water and fat
Organization in living things
● A cell is the smallest part of a human being e.g red blood cells
● Tissue refers to a group of similar cells working together to carry out the same function
e.g blood, phloem
● Organ refers to two or more tissues working together e.g heart
● System refers to a number of organs working together to carry out a function e.g
digestive system
● Organism refers to a living thing
What are the different types of digestion?
● Digestion refers to the breakdown of food
● Digestion is necessary to break down large, insoluble food into smaller, soluble particles
so that the nutrients can be carried around the body and used
● Physical digestion involves teeth breaking down food
● Chemical digestion i nvolves the use of enzymes to break down food
What are the characteristics of the mouth?
Physical digestion - teeth break down food into smaller pieces by chewing
● Chemical digestion - salivary glands makes saliva which contains the enzyme amalyse,
which digests starch to produce the sugar maltose
What are the characteristics of the Oesophagus?
● Passes food to your stomach
● A muscular tube that forces food down to the stomach by using a wave of muscular
action known as peristalsis
What are the characteristics of the stomach?
● Muscular bag that holds two litres of food
● Physical digestion - muscular walls churn and mix the food into chyme
● Chemical digestion - secretes hydrochloric acid to kill and soften food
What are the characteristics of the small intestine?
● 6m long
● Digested food passes into the bloodstream
● Produces many enzymes to complete the digestion
● Two important liquids are added here:
1. Pancreatic juice (produced in the pancreas)
2. Bile (produced in the liver)
What are the characteristics of the Pancreas?
● Produces amalyse and pancreatic juice
● Produces enzymes that pass into the small intestine to help with digestion
What are the characteristics of the liver?
● Produces bile which helps to digest and break down fat
What are the characteristics of the large intestine?
● Mainly fibre, dead cells and water reach here
● Most of the water is absorbed into the bloodstream
● Too much liquid content will result in diarrhea
● Too much liquid taken back causes constipation
● Faeces are stored in the rectum
● Eventually excreted out of the anus, roughly 24-48hrs after eating
What are enzymes and list examples
● Catalysts are chemicals that speeds up a reaction without getting used up in the reaction itself
● Enzymes are biological catalysts and proteins
● The substance that an enzyme acts on is the substrate a nd the substance formed by
the reaction is the product
● Amalyse is an enzyme found in s aliva
● Amalyse breaks down starch to form a sugar called m altose
● Therefore, starch is the substrate a nd maltose is the product
What are genetics?
● Genetics refers to the study of how traits/characteristics are inherited
List Human Characteristics
Human Characteristics ● One nose ● Two eyes ● Fingernails Variations ● Height ● Accent ● Interests Inherited Characteristics ● Controlled by genes ● Passed on from parents to children ● Eye colour, shape of face, ability to produce substances such as saliva Non Inherited Characteristics ● Not controlled by genes ● Learned throughout life ● Reading, musical instrument Chromosomes ● Thread like structures ● Found in the nucleus ● Made of DNA and protein ● Contain genes (a section of DNA that can produce protein) Chromosome numbers ● 46 chromosomes in the body ● 23 pairs (sperm and eggs only have 23 chromosomes altogether) ● At fertilisation, the number doubles to 46
