Biology Flashcards
1
Q
What is the function of the mitochondria?
A
- “power plants” of the cell
- the mitochondria convert energy to a readily usable form (ATP) though a process called cellular respiration
- active cells have more mitochondria than those that are less active
2
Q
What is the function of the nucleus?
A
- contains genetic information (DNA) that controls all cell activities (the DNA dictates what kinds of proteins are synthesized which dictates the rest of the cell activities)
- the genetic information (DNA) is stored on chromosomes, which carry the genetic instructions (EX: when a cell divides, DNA is copied)
3
Q
What is the function of the cell membrane?
A
- regulates the transport of materials entering and exiting the cell (it is semipermeable)
- this protects the cell and allows necessary materials to enter the cell
- EX: Oxygen must pass through the cell membrane so that the mitochondria can convert energy to am easily usable form (ATP) through cellular respiration
4
Q
What is the function of the ribosomes?
A
- they are responsible for making proteins in a process called protein synthesis
- they also facilitate the process of translation, where the genetic code is decoded to make specific proteins
5
Q
What is the function of the cell wall? PLANT CELLS ONLY
A
- OUTSIDE of the cell membrane
- rigid, providing the plant with structural support, shape and protection for the cell
- made of cellulose
- they are semi-permeable
- allows the plant to gain turgor pressure (the pressure of the cell contents against the cell wall, contributing to the rigidity of plant tissues)
6
Q
What is the function of the chloroplast? PLANT CELLS ONLY
A
- they perform photosynthesis, converting light energy into chemical energy (glucose/sugars) and releasing oxygen
- they also aid in the synthesis of other important molecules such as amino acids
7
Q
What is the function of the vacuoles?
A
- help in the storage and disposal of various substances
- they can store food and other nutrients the cell requires to survive
- they also isolate waste products to prevent the entire cell from contamination
STRUCTURE
- animal cells have many small vacuoles that are not visible
- mature plant cells typically have one large vacuole that is visible under the microscope (to fill with water to create turgor pressure that allows the cell to stand)
8
Q
What are the main differences between plant and animal cells?
A
- plants cells have chloroplasts that execute photo synthesis and give the plants their green colour
- plant cells have the additional cell wall which increasses rigidity, gives the plant cell a more rectangular shape, and allows for turgor pressure
- plant cells have a larger vacuole for maintaining turgor pressure, whereas animal cells have larger quantities of small vacuoles
9
Q
What is the function of the cytoplasm?
A
- stores water and other substances until they will be needed
- several processes/chemical reactions occur here, which can change the consistency of the cytoplasm (from jelly-like to liquid), allowing the organelles to move around
10
Q
What is the function of the nuclear membrane?
A
- to separate the cytoplasm from the nucleus
- to protect the DNA
- to regulate the movement of molecules in and out of the nucleus
11
Q
What is the function of the endoplasmic reticulum?
A
- a three-dimensional network of branching tubes that transport materials, such as proteins, throughout the cell
- the rough ER has ribosomes that synthesize proteins, which migrate into the tubules of the rough ER for transport to the Golgi apparatus
- the smooth ER functions in lipid metabolism (cholesterol and fat synthesis break down)
- detoxification of drugs and pesticides
12
Q
What is cellular respiration?
A
- the process in which cells break down glucose in the presence of oxygen to release chemical energy (ATP) for cellular processes, producing carbon dioxide and water as its waste products
13
Q
Why are plant cells more rectangular?
A
- due to their rigid cell wall made of cellulose, which provides the cell with structural support
14
Q
What is the difference between prokaryotic cells and eukaryotic cells?
A
Prokaryotic cells
- prokaryotic cells have no nucleus to contain their DNA (they BOTH have DNA)
- no membrane-bound organelles
- a much simpler structure than eukaryotic cells
15
Q
What is the difference between a prokaryote and a eukaryote?
A
Prokaryote:
- organisms that contain cells without a nucleus or membrane bound organelles
Eukaryote
- organisms that contain cells with a nucleus and membrane bound organelles
16
Q
What are the similarities between prokaryotic and eukaryotic cells?
A
- they have DNA
- they have ribosomes
- they have cytoplasm
- they have a cell membrane (also known as plasma membrane) ALL cells have a cell membrane
- most prokaryotic cells have cell walls
17
Q
Why do we breathe faster when we exercise?
A
We breathe faster in order to take in more oxygen in a shorter amount of time for the mitochondria to produce glucose for the muscles. In other worths the mitochondria needs more oxygen to produce more energy, since we are burning the energy when we exercise.
18
Q
Why do we have many small cells rather than fewer big ones?
A
- Cells are more efficient at transporting materials in and out when they are smaller
- Different cells have different functions, so it is important to have each type of cell
- Cells die all the time, so there must be multiple cells of the same function
19
Q
What is diffusion?
A
Diffusion is the movement of molecules or other particles from an area of high concentration to an area of low concentration until they are evenly distributed
20
Q
What is the definition of concentration?
A
The number of molecules of a substance (solute) in a given volume
21
Q
What is osmosis?
A
Osmosis involves the diffusion of water molecules across a semi-permeable membrane is from a region of high water concentration to low concentration of water
22
Q
What is the difference between diffusion and osmosis?
A
Diffusion is the distribution of molecules until the particles are evenly distributed, whereas osmosis is a specific type of diffusion in which ONLY water molecules move across a semi-permeable membrane only for the purpose of balancing the amount of water. In other words, osmosis is the movement of water in and out of a cell.
23
Q
What is an isotonic solution and which cells work best in this solution?
A
A solution with equal amounts of water and solute, best for animal cells because there net movement of water in and out of the cell.
An animal cell cannot have too much water because the cell will burst, and cannot have too little water because it will dehydrate.
24
Q
What is a hypotonic solution and which cells work best in this solution?
A
A solution that has more water, less solute (lower concentration of solute) is best for plant cells because water will enter the cell (to balance out the solution), which will cause the vacuole to fill with water, press up against the cell membrane and cell wall, creating tugor pressure that allows the plant to stand up.
25
What is a hypertonic solution?
A solution in which there is more solute than water, which will cause water to leave the cell
26
Describe the stages of an animal cell with a isotonic, hypotonic and hypertonic solution.
Animal cell
Isotonic solution: no net movement of water > BEST
- the net movement of water is zero in this kind of solution, which does not disrupt animal cell function
Hypotonic: too much water enters the cell, which may cause the cell to burst (it does not have the protective cell wall)
Hypertonic: water leaves the cell and causes the cell to shrivel
27
Describe the stages of a plant cell with a isotonic, hypotonic and hypertonic solution.
Plant cell in a
Isotonic: no net movement of water
Hypotonic: the central vacuole fills with water, turgor pressure develops (causing the cell to be stronger) and chloroplasts are seen next to the cell wall > BEST
Hypertonic: water will leave the cell, the vacuole loses water, the cytoplasm shrinks, and the chloroplasts are seen in the center of the cell
28
Animal cells are best in what solution?
Isotonic
29
Plant cells are best in what solution?
Hypotonic
30
What is turgor pressure?
The pressure exerted by the fluid in a cell, pushing the cell membrane against the cell wall, contributing to the cells rigidity
31
What is it called when the cytoplasm shrinks?
Plasmolysis
32
What is the life cycle of a cell?
Interphase (Ross says we are interfacing)
Mitosis:
- Prophase
- Metaphase
- Anaphase
- Telophase
Cytokinesis
33
What is interphase?
- the longest stage
- during this stage, the genetic material (DNA) is in long and thin strands (invisible) called chromatin (long and thin, chromatin)
- when the cell prepares for cell division, the strands are duplicated so that there are two identical strands of the genetic material (sister chromatids)
-> it is important that there are two identical strands because the next cells produced must be of the same type to execute certain functions
34
What is mitosis (general idea)?
The process in which a cell divides to form two identical cells
35
What is prophase?
- the first and most extended phase of mitosis
- the sister chromatids condense, forming chromosomes (chromosomes are easier to work with like putting your belongings into a box when packing)
- the chromatids are joined at their centromeres
- spindle (fibre) begins to form from the aster and stretch across the cell
- the nucleus dissolves/disappears
36
What is metaphase?
- the spindles pull the chromosomes so that they align to the middle of the cell
- they are properly aligned so that they are prepared for separation
THINK: M for middle and for metaphase
37
What is anaphase?
- shortest phase
- centromeres are separates
- the chromosomes each divide into two sister chromatids
- the two sister chromatids are moved to the opposite sides of the cell by the spindles
- the cell elongates
- by the end, the two ends of the cell have equivalent (complete) sets of chromosomes
THINK: A for apart and for anaphase
38
What is telophase?
- new nuclei form around the chromosomes on each side of the cell
- chromosomes become less condensed
- mitosis is complete
THINK: The chromosomes must telephone to each other now
39
What is cytokinesis?
- The stage in which the cytoplasm divides, causing the two daughter cells to appear
- in animal cells, constricting outside of the cell causes a cleavage furrow to form, which eventually pinches the cells apart
- due to their rigid cell wall, plant cells cannot undergo this change. Rather, a cell plate (a baby cell wall) forms between the daughter cells, and this pushes them apart
THINK: CYTO for CYTOKINESIS and CYTOPLASM
40
What is the difference in cytokinesis for plant and animal cells
Animal cells:
- constriction outside of the cell forms a cleavage furrow which eventually pinches the cells apart
Plant cells:
- plant cells cannot be pinched apart like this due to their rigid cell walls
- a cell plate (baby cell wall) is formed between the daughter cells, which eventaully pushes the cells apart
41
Which cells do not undergo mitosis?
Sperm and egg cells
42
Why is cell division important?
- growth (we cannot grow without new cells)
- repair (cell die all the type or we have wounds that need repairing)
- reproduction of single-celled organisms
43
How many chromosomes do we have?
46
44
Why is it important that cells divide to create two of the same cells?
Because if you change the cell identity, there could be issues as to what task the cell performs. For example, if new cells are produced to heal a wound, stomach cells cannot be produced there,
45
Is it possible for a cell to form a new type of cell in mitosis?
Yes. Although mitosis results in two identical daughter cells, when cell division goes wrong, a cancer cell can be produced
46
What are the functions of the golgi bodies?
- as the mail room of the cell, the Golgi bodies receive cellular proteins from the ER and modify and package them before sending them throughout the cell (different locations depending on their functions)
- they also package, modify and transport other materials like the enzymes in lysosomes
47
What are the differences between sexual and asexual reprodcution?
Asexual
- one parent
- offspring is genetically identical to the parent
- simpler process
Sexual
- 2 parents/gametes
- offspring with genetic information from each parent
more complex
48
What type of sexual reproduction is mitosis?
ASEXUAL
49
What is the process of moving things in and out of cells called?
Osmosis and diffusion
Osmosis is the diffusion of a water molecule across a membrane in response to concentration differences. Water always moves towards where the solution is more concentrated.
Diffusion is when various molecules move in and out of the membrane to have more equilibrium
OSMOSIS: ONLY WATER
50
How does the size of the cell affect the distribution of nutrients throughout the cell?
The smaller the cell, the better the ratio of volume to surface area for the purpose of material exchange done through diffusion and osmosis
51
How does the ratio of surface area to volume help you determine optimal cell size?
The higher the ratio of surface area to volume the better. This is because this allows for more room for material exchange with the atmosphere.
52
What is the definition of concentration?
Concentration is the number of molecules of a substance (solute) in a given volume.
53
Why is it wrong to say that interphase is inactive/ a rest phase?
Because during interphase, the cell is executing its typical functions, cellular respiration, and the replication of DNA
54
Why is it important that a cell copies its DNA?
The cell must copy its DNA so that the daughter cells receive a complete and identical set of genetic information crucial for growth, repair, and reproduction.
Also, when there is a random change in DNA (a mutation) cancer is a result
55
Why are chromosomes visible during mitosis, but no other time?
Because when not in mitosis, chromatin (which packages the DNA) is long and thin. However, during mitosis, the chromatin condenses because it is easier to move around to divide it
56
What is cell theory?
All living things are made up of one or more cells, cells are the basic unit of life, and all cells come from pre-existing cells
57
Why does it matter what type of solution a cell is in?
When a cell is placed in a solution with a different ratio of water to solute, the water molecules will move across the cell membrane to equalize the amount of solute inside and outside of the cell.
This water volume impacts the cell's function and shape
58
What is the difference between the ER and the golgi bodies?
The ER synthesizes proteins and transports them
The Golgi body modifies and packages them.
59
What is the definition of cancer?
A broad group of diseases in which cells grow and divide out of control
60
What is the definition of a tumour, benign tumour, and malignant tumour?
Tumour:
A mass of cells that continue to grow and divide without any obvious function in the body
Benign tumour:
A tumour that does not affect surrounding tissues other than physically crowding them
Malignant tumour:
A tumour that interferes with the functioning of surrounding cells; a cancerous tumour
61
What is a mutation?
A random change in DNA, which can result in the cell growing uncontrollably (without different instructions and functions), forming a tumour that could potentially, become a tumour that affects the functionality of the organ in which the tumour was formed.
62
What is a carcinogen and examples?
Any environmental factor that causes cancer
Examples:
- radiation (tanning beds, sunlight)
- tobacco (cigarettes)
- alcohol
- certain chemicals in plastics
63
What are some lifestyle choices one could make to avoid cancer?
- maintain a healthy diet (lots of fruits vegetables, and "superfoods", less fatty meats)
- maintain a healthy weight
- avoid carcinogens
- get regular screenings
64
What are some different screening methods?
- self-examination
- check for lumps on breasts for breast cancer
- check skin for cancer moles (can also be done by a dermatologist)
- testicular cancer
- pap test
- a doctor takes cervical cell samples for observation (cervical cancer screening
- blood test (also called PSA test)
- prostate cancer
65
What is an endoscopy?
- diagnosing colon cancer
- a cable is inserted into the colon through the rectum with a light and tiny camera that projects what is seen onto a screen
66
What is a biopsy?
- diagnosing
- a small sample from within the colon (or any part of the body) derived (from the endoscopy) using forceps to be studied under the microscope
67
What is an X-Ray?
- diagnosing
- a technique that uses radiation to create images of the inside of the body
68
What is a mammogram?
- diagnosing
- a specialized x-ray technique for imaging breast tissue
69
What is an ultrasound?
- diagnosing
- uses ultra-high frequency sound waves to create a digital image, which allows doctors to see certain soft tissues
70
What is a CT scan?
- diagnosing
- allow the x-ray technician to take multiple x-rays of the body from many different angles
- the images are then assembled by a computer to form a series of detailed images, allowing doctors to see part of the body that they would not normally be able to see
71
What is an MRI?
- diagnosing
- uses a strong magnetic field to create images with more detail than a CT scan
- computers assemble the information into 3D models
72
What are the methods for diagnosing cancer?
- MRI
- X-Ray
- ultrasound
- CT
- Mammogram
- Biopsy
- Endoscopy
73
What are the 4 methods of treating cancer?
Surgery
- physically removing the tumour, which is preferred, especially if the tumour is easily accessible and well defined
Chemotherapy
- drugs
- injected or oral
- may cause nausea, hair loss, fatigue
- beneficial because the drug travel throughout the body, killing any other tumours that were too small to be seen
Radiation
- the ionizing radiation kills the cancer cells
- the ionizing radiation kills the DNA of daughter cells preventing them from growing
- the radiation would be directed towards the tumour
Biophotonics
- new tech
- a manner of using light energy to diagnose, monitor and treat cells and organisms
74
Why is there a risk of surgery recurring, even after treatment?
Because some cancer cells may survive and eventually grow back, leading to a new tumour and/or cancer
75
How can one inherit cancer genetically?
One can inherit the DNA that is linked to cancer
76
What is meant by uncontrolled cell division?
Due to a mutation, the DNA of a cell is changed, causing its replication to be abnormal in the sense that it replicates continuously, despite the nucleus and other organelles telling it to stop. Also, the cells do not have a necessary function for the body, which can cause them to interfere with the function of the organ
77
What is function of the ocular lens/eyepiece?
- the part one looks through to view the object
- magnifies the image of the object by 10x (usually)
78
What is the function of the body tube?
- contains the ocular lens/eyepiece
- supports the objective lenses
79
What is the function of the stage?
- supports the microscope slide
- has a central opening that allows light to pass through the slide
80
What is the function of the clips?
- holds slide in position
81
What is the function of the diaphragm?
- controls the amount of light that reaches the object being viewed
82
What is the function of the coarse adjustment nob?
- moves the body tube up or down to get the object into focus
- used with the low-power objective lens only
83
What is the function of the fine-adjustment nub?
- moves the tube to get the object into sharp focus
- used with medium and high power magnification
84
What is the function of the arm?
- connects the base to the body tube
- a place from which one holds/carries the microscope
85
What is the function of the light source?
- maybe an electric light bulb or a mirror that can be angled to direct light to the object being viewed
- is only used after the object has been centred and prepared
86
What is the function of the nosepiece?
- hold the objective lenses
- rotates, allowing the objective lenses to be changed
87
What is the function of the base?
- serves as a support for the microscope
88
What is metastasis?
The process of cancer cells breaking away from the original (primary) tumour, establishing another (secondary) tumour elsewhere in the body
89
What is the function of the lysosomes?
- look like sacs
- break down waste materials and unused parts inside the cell through the use of enzymes and acids
90
What is the cell membrane made of?
Phospholipids
91
What are chromosomes made of?
DNA and protein
92
How would a cancer cell's life cycle be different from that of a regular cell?
- normal cells divide only when they receive signals to do so, whereas normal cells ignore these signals and continue to divide, even when they are not needed. Hence their cycle might be different because they are in interphase for a shorter period of time.
- cancer cells do not have specific functions to carry out during interphase
- cancer cells do not die
93
What are biophotonics?
- newest weapon to treat cancer
- uses beams of light to detect and treat cancer
- fewer side effects than radiation therapy as the beams are better at targeting the cancerous tissue
94
What is genetic screening?
It involves examining DNA to detect changes (mutations) in genes that could cause cancer
An aim to identify those who are at a higher risk of developing cancer due to an inheritance of the mutation.
95
What is the shortest phase of mitosis?
Anaphase
96
Why are proteins so important?
Proteins do most of the work of living cells. They transcribe DNA and produce, process, and secrete other proteins
97
What are examples of prokaryotes?
Bacteria and archea
98
Are eukaryotic or prokaryotic cells more efficient? Why?
Eukaryotic cells are more efficient because:
- they have more organelles that execute many functions
- eukaryotic cells are compartmentalized (different regions of the body have cells with specific functions, allowing cells to be specialized)
- the addition of organelles in eukaryotic cells increases the surface area INSIDE the cell, allowing for more efficiency in cell processes
99
Why do we need the cell membrane when speaking about water?
Water must pass through the semi permeable membranes of our cells to get from one spot in our body to another
100
What are some examples of when osmosis occurs?
- the cells of plant roots absorb water from the soil
- water is released as a waste products after cellular respiration
- feeling thirsty after drinking water (our blood draws fluid from our tissues to dilute the excess sodium)
101
Are prokaryotic or eukaryotic cells larger (usually)?
Eukaryotic cells are larger due to their organelles and membrane-bound organelles
102
Is an amoeba prokaryotic or eukaryotic?
Eukaryotic
103
Why are IVs not solely water?
Because when the water goes into the blood, since the blood cells have a higher solute concentration, the water would enter the cells and cause them to burst. So, when one gets an IV they will have a solution that is isotonic to their blood (no swelling or shrinking red blood cells)
104
