Biology 1 - Cell Biology Flashcards
(108 cards)
1
Q
Organisms can be classified into?
A
- Eukaryotes
- Prokaryotes
2
Q
what are eukaryotes made up of?
A
Eukaryotic cells
3
Q
what are prokaryotes made up of?
A
Prokaryotic cells
4
Q
Name the subcellular structures in both animal cells and plant cells?
A
- Nucleus
- Cytoplasm
- Mitochondria
- Ribosome
5.Cell Membrane
5
Q
Name the extra subcellular structures found in plant cells?
A
- Permanent vacuole
- Chloroplasts
- Cell wall
6
Q
Function of the Nucleus?
A
Contains the genetic material that controls the activity of the cell.
7
Q
Function of Cytoplasm?
A
It is a gel-like substance where most chemical reactions takes place and it contains enzymes.
8
Q
Function of Cell Membrane?
A
Holds the cell together and controls what enters and what exits it
9
Q
Function of Mitochondria?
A
Where most of aerobic reaction takes place. Respiration transfers energy that the cell needs to work.
10
Q
Function of Ribosomes?
A
Where protein is made in the cell
11
Q
Function of Cell Wall?
A
Made up of cellulose. It supports and strengthens it.
12
Q
Function of the Permanent Vacuole?
A
Contains cell sap (a weak solution of sugar and salt).
13
Q
Function of Chloroplasts?
A
Where photosynthesis occurs and it contains chlorophyll which absorbs light which is needed for photosynthesis.
14
Q
Learn how to identify the different subcellular structures on both plant and animal cells
A
Do the same for the Bacteria cells
15
Q
Size of Bacteria cell compared to animals and plants cells
A
Much smaller
16
Q
Are bacteria prokaryotes or eukaryotes?
A
Prokaryotes
17
Q
Name the different subcellular structures of a bacteria cell?
A
- Single circular strand of DNA
- Plasmids
- Cytoplasm
- Cell membrane
- Cell wall
- Does not have a chloroplast or mitochondria
18
Q
Name the 2 different types of Microscopes?
A
- Electron
- Light
19
Q
What does light microscope use to form an image of a specimen?
A
It uses light & lens
20
Q
What does electron microscope use to form an image of a specimen?
A
it uses Electrons & Lens
21
Q
Which microscope Has a higher magnification and higher resolution?
A
Electron
22
Q
Define Resolution?
A
It is the ability to distinguish between two points.
23
Q
What is the formula to calculate magnification?
A
magnification = image size/real size
24
Q
Practices using the formula for microscopes?
A
25
How to prepare a slide to view onion cells?
1. Add a clean drop of water in the middle of the clean slide.
2. Cut the onions and separate into layers.
3. Place the tissue into the water on the slide.
4. Add a drop of iodine solution ( a stain).
5. Place a cover slip on top.
26
Why do you cut the onions and separtae them into layers?
Use tweezers to peel off some epidermal tissue from the bottom of one layer
27
Why do you add a drop of iodine solution to the epidermal tissue?
This is to highlight objects in a cell by adding colour to them.
28
How do you place a cover slip on the specimen?
1. Stand it upright, next to the water droplet.
2. Carefully tilt and lower it so it covers the specimen.
3. Try not to get any air bubbles under there as they will obstruct your view of the specimen.
29
How to use a light microscope?
1.Clip the slide onto the stage
2.Select the lowest powered objective lens - lowest magnification
3.Use the coarse adjustment knob to move the stage up to just above the objective lens.
4. Look down at the eye piece and use the coarse adjustment knob to move the stage downwards till the image is roughly in focus
5. Adjust the focus with a fine adjustment knob until you get a clear image.
6. If you need to see the slide with greater magnification swap to a higher powered objective lens and refocus.
30
Learn the different parts of a light microscope.
31
Drawing your observation of your specimen?
1. use a pencil with a sharp point.
2. Make sure your drawing takes at least half the space available and it is draw with clear unbroken lines
3. no colouring or shading
4.if your drawing a cell the subcellular should be in proportion.
5. Add a title and write the magnification
6. label important subcellular structures with straight and not uncross lines
32
Practice drawing specimens from the microscopes
33
Define Differentiation ?
It is a process by which a cell changes to become specialized.
34
What are undifferentiation cells?
Stem Cells
35
What are cells that differentiate in mature animals mainly used for?
1. Repairing and replacing cells such as blood and skin cells.
36
In most animal cells do they lose the ability to differentiate at a early stage?
Yes, after they become specialized.
37
In most plant cells do they lose the ability to differentiate at a early stage?
No, they keep the ability
38
What happens when cell's changed
They develop different subcellular structures and turn in to different types of cells and this allows them to carry out specific functions.
39
Name 6 different specialized cells and what they are specialised for
1.Root hair cells - Absorbing water and minerals
2.Xylems cells - transporting substances
3.Phloem cells - transporting substances
4.Muscles cells - contraction
5.Nerve cells - rapid signalling
6. Sperm cells - reproduction
40
Function of Sperm cells?e
1. To get the Male DNA to the Female DNA
2. It has a long tail and a streamlined head to help it swim to the egg
3. Lots of mitochondria in the cell to provide the energy needed
4. Carries enzymes in its head to digest through the eggs cell membrane
41
Functions of a Nerve Cell?
1. Carries electrical signals from one part of the body to another.
2. Cells along to cover more distances
3. have branch connections at their ends to connect to other nerve cells and form a network through out the body
42
Functions of a muscle cell
1. To contract quickly
2. they are long so they can have space to contract.
3. lots of mitochondria to generate the energy needed for contraction.
43
Functions of root hair cells
They are cells on the surface of plant roots, which grow into long "hairs". which sticks out of the soil, this gives the plant a big surface area for absorbing water and mineral ions from the soil
44
Function of Phloem & Xylem cells
1.it is to transport substances such as food and water around the plant.
2. the cells are long and join end to end .
3. Xylem cells are hollow in the centre and Phloem cells have very few subcellular structures so stuff can flow through them.
45
Be able to identify the different specialised cells
46
What is inside the nucleus?
Chromosomes - genetic material
47
What are Chromosomes?
They are coil up lengths of DNA molecules
48
Different Genes control what?
the development of different characteristics like hair colour
49
How many copies of each chromosomes does a body cell normally have?
2 copies, one from the mother and one from the father
50
How many chromosomes does a human have?
23 chromosomes
51
the stage of the cell cycle when the cell divides is called what?
Mitosis
52
Multi-cellular organism uses mitosis to do what?
To grow or replace cells that have been damaged
53
What is the outcome of the cell cycle?
2 new cells identical to the original cell with the same amount of chromosomes
54
What are the 2 main stages of the cell cycle?
1. Growth and DNA replication
2. Mitosis
55
What happens in growth and DNA replication?
1.DNA is spread out in a long strings
2. Before it divides the cell has to grow an increase the amount of subcellular structures such as mitochondria and ribosomes
3.It duplicates the DNA so their is a one copy for each new cell. The DNA is copied and forms X shaped chromosomes
56
What happens in Mitosis?
4. Chromosomes line up in the centre
5. cell fibres pull them apart so 2 arms of each chromosomes goes to opposite sides of ends of the cell.
6.Membrane form around each of the sets of chromosomes these become the nuclei of the 2 new cells - the nucleus has divided.
7. The Cytoplasm and cell membrane divide
8. 2 new genetic identical daughter cells are produced
57
Where can stem cells be found?
Early human embryos, bone marrow
58
What can bone marrow and early human embryo turn into any type of cells?
Only embryotic stem cells. bone marrow can produce certain ones such as blood cells
59
How do you produce clones?
Stem cells from embryos and bone marrow can be grown in a lab and made to differentiates to specialised cells to uses in medicine and research
60
What are clones?
Genetically identical cells
61
What happens during therapeutic cloning?
It is a Embryo that has the same genetic information as the patient that means the stem cells produce from it would contain the same genes so it wouldn't be rejected by the patient's body if used to replace faulty cells,
62
What are the risk using stem cells in medicine?
Stem cells grown in the lab may become contaminated with a virus which could be passed on to the patient to become more sicker
63
What are Embryonic stem cells be used for?
be used to replace faulty cells in sick people. For example you can make insulin producing for people with diabetes, nerve cells for people who are paralysed by spinal injuries and so on.
64
Why do people use stem cells transferred from the bone marrow of a healthy person?
To replace faulty blood cells in a patient who receives them.
65
Why are some people against stem cell research?
1.They feel that human embryos shouldn't be used for experiments since each one a potential human life.
2. Campaigner believes other forms of stem cells should be used instead of embryo's
3. Curing existing patients who are suffering is more important then a right of a embryo.
4. Embryo's are usually unwanted one's from fertility clinics which they argue if they weren't used for research they would be just destroyed.
66
Where are stem cells found in plants?
Meristem's
67
Through out the plant entire life what can differentiate in any type of plant cells.
Cells which are located in the Meristems
68
Advantages using stem cells to produce clones of whole plants?
1. It is quicker and cheaper
2. grow more plants or rare species to prevent it from being wipe out
3. Be use to create crops of identical plants that have desired features for farms for example dieses resistant
69
Define Diffusion?
Diffusion is the spreading out of particles from area of a higher concentration to an area of low concentration
70
Diffusions occurs in ?
solutions and gases
71
How does diffusion rates increase?
1. The bigger the concentration gradient, the faster the diffusion rate
2. The higher the temperature, the faster the kinetic energy so the faster the diffusion rate.
3. The larger the surface area of the membrane, the faster the diffusion rate because more particles can pass through at once.
72
What type of molecules can diffuses through the cell membrane?
Only very small molecules like oxygen, glucose, amino acids and water
73
What type of molecules cannot diffuse through the cell membrane?
Big molecules like starch and proteins
74
How does the particles flow through the cell membrane?
From where there is a higher concentration ( a lot of them) to where there is a lower concentration ( not a lot of them).
75
How do particles move in diffusion?
Randomly so they go both ways - but if there are a lot more particles on one side of the membrane, there is a net (overall) movement from that side.
76
Define osmosis?
The movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
77
What is a partially permeable membrane?
it is a membrane is just one with many small holes in it. Only tiny molecules can pass through them, and bigger molecules cannot.
78
How does water molecules in osmosis move?
Randomly so they go both ways as there are more water molecules on one side than the other side. There is a steady net flow of water into the region with fewer water molecules. As a result, the strong sugar solution gets more dilute.
79
How do you observe the effect of sugar solution on plant tissue?
1.cut a potatoes into identical cylinders and get some beaker with different sugar solution in them. one should be pure water and another should be a very concentrated sugar solution. Also have a few others in between.
2. measure the mass of the cylinders and leave one cylinder in each beaker for 24 hrs
3. take an amount and dry it with a paper towel and measure their masses again.
4. if the cylinders have drawn in water by Osmosis, they would increase the mass if its the opposite then it decrease in mass .
5.calculate the percentage change in mass then plot a few graph.
80
What is the dependant variable and the independent variable and what should be kept the same in observing the effects of sugar solutions on plant tissues?
1. Dependant variable is the chip mass
2. Independent variable is the concentration of the sugar solutions
3. Kept the same are the volume of solution, temperature, time, type of sugar used and etc.
81
What are the errors that could arise in observing the effects of sugar solutions on plant tissues?
1. Some potato cylinders were not fully dried
2. Excess water would giver higher mass
3. If water evaporated from the beakers
4. The concentrations of the sugar solutions would change
82
How do you reduce the errors in observing the effects of sugar solutions on plant tissues?
1. By repeating the experiments 3 times minimum
2. Calculate the mean percentage change at each concentration.
83
how do root hair cells take minerals and water?
Active transport - the concentration of minerals is usual higher in the root hair cells in the soil around them therefor root hair cells can not use diffusion to take up minerals from the soil. it need to absorb against the concentration gradient - to a lower to a higher concentration
84
What does active transport require?
Energy from respiration is needed for it to work.
85
Where does active transport occur in human ?
Taking glucose from the gut and kidney tubules.
86
How is water taken in root hair cells?
Osmosis
87
How does active transport occur in the gut?
When their is a lower concentration of nutrients in the gut but in a higher concentration blood
2. when their is a higher concentration of glucose and amino they diffuse natural into the blood but sometimes their is a lower concentration of nutrients in the gut then their is in the blood as a result active transport allow nutrients to be taken into the blood this mean glucose can be taken in to the blood stream in the concentration of the blood which higher then the gut it can be transported cell where its used in respiration.
88
The larger the organism is what is the surface area compared to its volume
its smaller
89
How do you calculate surface area to a volume ratio
the volume the block is length x width x heigh
length x width surface area simplify one ratio
90
Why do multi-cellular organism need exchange surfaces?
They have a smaller surface area compared to their volume so not enough substances can diffuse to supply their entire volume
91
How exchange surfaces adapted to maximises effectiveness?
1. Thin membrane substance has a short distances to diffuse
2. Large surface area so lots of them can diffuse at once.
92
How does Gas exchange happen in the lungs?
It occurs in the little air sacs alveoli
93
How is Alveoli specialised in the diffusion of oxygen and carbon dioxide
1. A large surface area
2. A moist lining for dissolving gases
3. Very thin walls
4. A very good blood supply
94
Where does gas exchange occur in the small intestines?
Little projections called Villi
95
How does the Villi provide a really large surface area?
1.A single layer of surface cell
2.A very good blood supply to assist rapid absorption
96
Where does gas exchange occur in plant?
Stomata - this is where carbon dioxide diffuses in through
97
What diffuses out of the stomata?
Oxygen and water vapour
98
How is the size of the stomata controlled?
Guard cells
99
When does the Stomata close?
If the plant is losing water faster then it is being replaced by the roots and also at night time due to photosynthesis not happening.
100
With out the guard cells what will happen?
The plant will wilt
101
How does the stomata increase the exchange surface?
1. The flatten shape of the leaf increases the area of this exchange surface so it becomes more effective.
2.The air spaces increases inside the leaf increases the area of the surface so their is a more chance that carbon dioxide to get into the cells.
102
Where does gas exchange occur in fishes ?
Gills
103
How does gas exchange occur in fishes ?
Water enters the fish through the mouth pass out through the gills
2. Oxygen diffuses through the water into the blood in the gills and carbon dioxide from the blood into the water
104
How does Gills provide a large surface area for gas exchange?
Gill filaments and they are covered in lamellae
105
How does Lamellae increases the surface area
1. They have lots of blood capillary to speed up diffusions
2. Thin layers of cells to minimise gases have to diffuses
106
How does a large concentration gradient between water and the blood?
Blood flows through the Lamellae in one direction and water flows in the opposite direction
107
What is higher the concentration of oxygen in the water or blood?
The Water so as much oxygen diffuses from the water into the blood
108
Practices the practical of Osmosis
