Living things
Define the word cell.
A cell is the smallest structural and functional unit of all living organisms.
How does a compound microscope differ from a magnifying glass?
A compound microscope has two lenses, one in the eypeice and one to three in the nosepiece.
When skin cells die, they make a tough outer layer called the _______________
Epidermis
Acetylcholine, which is found in nicotine, is a neurotransmitter that is categorized as ______________ because it increases the blood flow in the circulatory system making your heart beat faster.
Stimulants as opposed to depressants.
Dopamine and Adenosine are both types of _______________
Neurotransmitters
Which of the following is not a required characteristic of something for it to be considered a "living thing?"
Living things obtain and use energy and eliminate waste.
Living things make their own food.
Living things reproduce.
Living things make their own food. Animals have to eat food, while plants often have to make their own from energy from the sun.
What do yeast cells do that causes bread to rise?
When they eat sugar, one waste product is carbon dioxide gas which makes little bubbles of air pockets in the bread dough.
What is in the nucleus of a cell that provides the coded instructions for how the cell grows and behaves?
DNA
This body system moves both internal parts like lungs, stomach, heart and external parts like arms and legs.
Muscular System
Yeast uses/eat sugar for two main reasons. What are they?
For energy and building resources (material to grow bigger and divide)
All living things are made of ____________
cells
Is yeast a unicellular or multicellular organism?Explain why.
Yeast is unicellular because it is a living thing made of one cell.
Explain why the following statement is false: There needs to be two cells to reproduce and make more cells.
Cells reproduce on their own by growing bigger and then dividing into two copies.
Name 3 of the 6 main body systems we studied.
Skeletal system, nervous system, muscular system, cardiovascular system digestive system, repiratory system
Red blood cells carry _________ to cells in a body and then carry ___________ away from the cells in a body.
Red blood cells carry OXYGEN to cells and then carry CO2 (CARBON DIOXIDE) away from the cells.
What is one characteristic of living things that fire has and what is one that it does not have?
Characteristics: Fire grows. Fire can be thought to reproduce as it can spread new fire to places. One could also make the argument that it uses energy and leaves waste behind when it burns things and that it responds to stimuli because it can go out if someone blows on it.
Characteristics it doesn't have: Fire is not made of cells and does not maintain stable internal conditions.
Which is larger, a caffeine molecule or a cell?
A cell is much larger than a caffeine molecule, almost 1000 times bigger.
Caffeine molecules are about 0.000000001 (8 zeros)
A red blood cell is about 0.000001 (5 zeros)
List two different organelles we studied and what they do.
Cell membrane - holds the cell together
Nucleus - controls the cell using the DNA
Mitochondria - takes in oxygen and food to make energy
Cell Wall - supports the cell and gives it structure.
Chloroplast - traps the suns energy to make food.
Explain what the nervous system does.
This system controls and coordinates the actions of the body by receiving signals, processing information, and transmitting responses. It interacts with memories and information from the outside world.
What is one type of organelle that animal cells don't have, but plants do have and explain why animal cells don't need it.
Chloroplast - Animal cells don't need this because animals eat things to get energy. Most plants don't eat other plants or animals so they need to get their energy through photosynthesis and the sun.
Cell Wall - Plants don't have bones, so cell walls help to provide structure to them.
Explain one way that a cloud is like a living thing, and one reason why it is not a living thing.
Living Characteristics a cloud has: Clouds can grow larger. Clouds respond to stimuli like heat or wind and can change to a gas.
Living Characteristics a cloud does not have: Clouds are not made of cells, do not eliminate waste, can't reproduce, cannot maintain their internal conditions and can't evolve.
Describe what adenosine molecules do in humans and why are they important?
Adenosine molecules bond to adenosine receptors in the nerve cells of humans and cause your body to be relaxed and tired. This helps you to get tired and to go to sleep.
Fill in the blank and answer the question.
A dendritic cell is a type of __ __ __ __ __ blood cell. What role of function does it serve?
White blood cell.
Dendritic cells help with the immune system by identifying foreign bodies and germs that should not be there.
Describe how the respiratory system and the circulatory system are connected.
The respiratory system brings in oxygen through the longs. Then the circulatory system takes that oxygen by way of red blood cells to other cells throughout the body. CO2 (carbon dioxide) is generated often as waste when the oxygen is used. The red blood cells in the circulatory system then take that CO2 back to the lungs where the respiratory system exhales it back into the air.
The scientist Otto Loewi hypothesized that nerves communicate using chemicals as well as electrical signals. Describe the experiment he conducted which proved this to be true.
Otto Loewi discovered the first neurotransmitter. In his experiment, he used two frog hearts. One heart (heart #1) was still connected to the vagus nerve. Heart #1 was placed in a chamber that was filled with saline. This chamber was connected to a second chamber that contained heart #2. So, fluid from chamber #1 was allowed to flow into chamber #2. Electrical stimulation of the vagus nerve (which was attached to heart #1) caused heart #1 to slow down. Loewi also observed that after a delay, heart #2 also slowed down. From this experiment, Loewi hypothesized that electrical stimulation of the vagus nerve released a chemical into the fluid of chamber #1 that flowed into chamber #2. We now know this chemical as the neurotransmitter called acetylcholine.