Exam Flashcards
What is the difference between animal and plant cells?
- Animal Cells are generally smaller than plant cells, ranging from 10-30 micrometers compared to 10-100 micrometers of the Plant Cells.
- Animal Cells are generally irregular or round shaped and plant cells are generally cubic or rectangular in shape.
- Animal Cells don’t contain a cell wall and only a cell membrane and plant cells contain both a cell membrane and cell wall.
Which is the animal cell, which is the plant cell?
The left cell is an animal cell and the right cell is a plant cell.
What are the charcteristics of a unicellular organism?
- The body is made up a single cell
- A single cell caries out all the life processes.
- Cell body is exposed to environment at all times.
What are the charcteristics of a multicellular organism and give an example?
- Body is made up of numerous cells
- Different Cells are specialised to peform different fucntions.
- Only outer cells are exposed to the environment
All species of animals, land plants and most fungi are multicellular
What are the pros and cons of unicellular and multicellular organisms?
Multicellular organisms have the advantages of an increase in size without its limitations. They can have longer lifespans as they can continue living when individual cells die. Multicellularity also permits increasing complexity by allowing differentiation of cell types within one organism. However, an advantage of a unicellular cell is that they can reproduce quickly.
How does Sa:V affect the size of a unicellular organism?
Since you’re talking about unicellular organisms, the main problem with growing bigger is a smaller surface area to volume ratio. That is, it has a lot of space where you need to take nutrients to, and lots of space where you need to take waste away from.
This is done by diffusion to save energy, but if a cell is huge but the cell membrane is relatively small, it just can’t keep up.
What is Osmosis?
Osmosis is the diffusion of water across a semi permeable membrane from an area of high water concentration to low water concentration.
What is diffusion?
Diffusion is the movement of molecules from areas of high concentration to low concentration in a free state.
Which of the following diargrams demonstrated Osmosis?
The Diagram on the left demonstrates Osmosis and the diagram on the right demonstrates Diffusion.
What is homestasis and give an example?
Homeostasis is the maintenance of organisms internal conditions to remain healthy and functioning regardless of external conditions. E.g The maintenance of a steady body temperature in warm blooded animals is an example of Homeostasis.
What two body systems maintain homestasis and how do they peform homeostasis?
The Nervous System and the Hormonal System
the nervous systeam detects changes in the environment and responds to changes in a fast short termed manner. The hormonal system is responsible for longer-term changes but take longer to take effect.
What conditions must be controlled in homeostasis?
The conditions that must be controlled in homestasis are Body Temperature, Water content, carbon dioxide level and blood sugar levels, etc…
How is sweating an efficient way of losing body heat?
It is efficient, as when sweat evaporates it removes heat, making you cooler.
Why do you feel cooler on a hot windy day, rather than a hot still day?
Because wind improves evaporation, so when you sweat it removes heat more efficiently.
What is a method to produce warm heat in the cold?
Shivering.
In order from A-F name the parts of a neuron?
A= Dendrites,
B= Nucleus,
C= Cell Body,
D= Myelin Sheath,
E= Axon,
F= Axon Terminal,
What is the role of the muscular system and its vital organs?
Enables movement, posture and balance and circulates blood, its major organs are skeletal muscles and blood vessels.
What is the role of the urinary system and what are it’s major organs?
To filter blood and remove waste from the body in the form of urine. It’s vital organs are the bladder, kidneys.
What is the role of the respiratory system?
To supply blood with oxygen in order for the blood to deliver oxygen everywhere, its vital organs are the lungs, trachea, bronchi and nose.
What is role of the digestive system and what are it’s vital organs?
It ingests and breaks down food so it can be absorbed by the body, its major organs are the escophagus, stomach, liver and small and large intestines.
What is the role of the endocrine system and what are it’s vital organs?
Secretes Hormones into bloodstreams for regulation of body activities, its major organs are the pituitary gland, the thymus and the thyroid.
What is the role of the skeletal system and what are its major organs?
Provides mechanical support for the body, stores minerals and produces red blood cells (carry oxygen around the body). Its major organs are bones and cartilage.
What is the role of the intergumentary system and what are its major organs?
It protects body from environment, injury and infection, its major organs are hair, skin and nails.
What is the role of the Nervous System and its major organs?
Senses environment; communicates with and activates other parts of the body, its major organs are the brain, spinal cord and nerves.
What is the role of the cardiovascular system and what are its major organs?
To transport nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes, its major organs are blood vessels and the heart.
What is the role of Lymphatic System and what are its major organs?
The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body. In other words protect against infection. Its major organs are the thymus, lymph nodes and lymphatic vessels.
