Nature and Variety of Living Organisms Flashcards
List the 8 characteristics of all living organisms;
- Require nutrition
- Respire
- Excrete waste
- Respond to surroundings
- Move
- Control their internal condition
- Reproduce
- Grow and develop
Describe three differences between the structure of a plant vs an animal cell
- Plants have a cell wall, animals do not
- Plants have chloroplasts, animals do not
- Plants have cytoplasm; animals have small vacuole s
What are the chemical elements present in carbohydrates?
Carbon, hydrogen and oxygen
What are the chemical elements present in proteins?
Carbon, hydrogen, oxygen and nitrogen
What are the chemical elements present in lipids?
Carbon, hydrogen, oxygen, nitrogen and phosphorus
What is the balanced word equation for photosynthesis?
Carbon dioxide + water = glucose and oxygen
What is the balanced chemical equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
How do levels of CO2 affect the rate of photosynthesis?
Since it’s a reactant, when the levels of CO2 increases, the rate of photosynthesis will therefore increase, and vice versa
How do levels of light intensity affect the rate of photosynthesis and the appearance of the leaf?
High light intensity increases the rate, and provide strong branches and dark green pigmentation
however low light intensity slows growth, and may cause leaf size to increase in size and become much lighter
How does temperature affect the rate of photosynthesis? Fully explain
At low temperature, the rate of photosynthesis is limites by the amount of mollecular collisions between enzymes and substrates. At high temperatures, enzymes will denature.
Describe a balanced diet:
Appropriate proportions of
- Carbohydrate
- Lipid
- Protein
- Vitamins
- Minerals
- Water
- Dietary fibre ( like oats )
Expain how energy requirements vary with age and activity levels
Children and adolscents require more energy for growth and development in comparison to adults.
Also, most adults are less active as they get older, so energy requirement goes down.
How do energy requirements change with pregnancy?
Extra energy is required for the growth and maintenence of the fetus and placenta.
Describe some characteristics and structure of fungi
- Not able to carry out photosynthesis
- Bodies usually organised into a mycelium from thread-like structures called hyphae
- Feed by saprotrophic nutrition (secreting digesting enzymes onto food & absorbing organic products)
Describe some characteristics and structure of protoctists
- microscopic, single celled organisms
- Some live in pond water and have features like an animal cell (Ameoba) while others (Chlorella) have chloroplasts and are more like plants.
- A pathogenic example is Plasmodium, responsible for causing malaria
Describe common feautures of plants:
- Multicellular
- Cells contain chloroplasts
- Able to carry out photosynthesis
- Cells have cellulose cell walls
- Store carbohydrates as starch or sucrose
Describe some common features of animals:
- Multicellular
- Cells do not contain chloroplasts
- Not able to carry out photosynthesis
- No cell walls
- Nervous co-ordination
- Store carbohydrate as glycogen
Describe common feautures shown by prokaryotic organisms (like bacteria)`
- Microscopic single celled organisms
- Contain a cell wall, cell membrane, cytoplasm and plasmids
- Lack a nucleus
- Contain a circular chromosome of DNA
- Some can carry out photosynthesis but most feed on dead or other living organisms
Describe what is meant by a pathogen
An organism that can produce disease
Describe some common features of a virus
- NON LIVING ORGANISMS
- Can ONLT reproduce inside living cells
- Infect every typr of living organism
- Smaller than bacteria
Describe the structure of a virus
- No cellular structure
- Have a protein coat
- Contain either DNA or RNA
- Smaller than bacteria
What is meant by the term organelle
cell structures that are specialised to carry out a specific function or job, IE: a nucleus
What is the role of cytoplasm?
- A jelly-like material
- Contains dissolved nutrients and salts and structures called organelles.
- Where many of the chemical reactions happen.
Role of the ribosome:
- Contain the enzymes for respiration
- Where energy is released during respiration
Role of the cell vacuole:
- Filled with cell sap to help keep the cell swollen
Role of the chloroplasts
- Site of photosynthesis
- Contains the enzymes needed for photosynthesis
