Topic 1 Cell Biology Flashcards
(111 cards)
1
Q
Give an example of a prokaryotic cell.
A
A bacterial cell.
2
Q
Give two examples of Eukaryotic cells.
A
An animal cell and a plant cell.
3
Q
What is a plasmid?
A
A plasmid is a circular piece of DNA.
4
Q
What are the three outer layers of a bacterial cell?
A
The slimy capsule, the cell wall and the Cell membrane.
5
Q
List 5 types of cells in our body.
A
Red Blood cell, Sperm cell, skin cell, White blood cell, Bone cell, salivary gland cell, Platelets, Muscle cell, root hair cell, Nerve cell.
6
Q
What are smaller Eukaryotic or Prokaryotic cells?
A
Prokaryotic cells.
7
Q
What is the form of the genetic material in a Prokaryotic cell?
A
It is a loop of DNA. Plasmids
8
Q
What is the cytoplasm?
A
The cytoplasm is a liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life takes place.
9
Q
What is the nucleus of an animal cell?
A
The nucleus is an organelle that encloses the genetic information.
10
Q
What is the job of the Cell membrane of an animal cell?
A
To control what enters and leaves the cell.
11
Q
What takes place in the mitochondria?
A
In the mitochondria aerobic respiration takes place.
12
Q
What form does genetic information take?
A
It takes the form of chromosomes and DNA.
13
Q
What are Ribosomes?
A
Ribosomes are the site of protein synthesis.
14
Q
What is smaller a Mitochondrion or a Ribosome?
A
A Ribosome.
15
Q
What are three common features of plant and animal cells (eukaryotes)?
A
1) Cell membrane; 2) Cytoplasm; 3) Genetic material in a nucleus.
16
Q
Which are bigger; bacterial cells (prokaryotes) or eukaryotes?
A
Eukaryotes.
17
Q
True or false? “Prokaryotic cells have a cell wall.”
A
True
18
Q
True or false? “Prokaryotic cells have a nucleus.”
A
False
19
Q
Name five common organelles of animal and plant cells.
A
Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
20
Q
Name two further features of a plant cell.
A
Chloroplasts, permanent vacuole (filled with cell sap) and cell wall.
21
Q
Describe the function of the chloroplasts.
A
The location of photosynthesis.
22
Q
What is the cell wall made of?
A
It is made of cellulose which strengthens the cell and gives support.
23
Q
Describe the function of the permanent vacuole.
A
A permanent vacuole is a space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant.
24
Q
What is the definition of a cell?
A
The individual unit of an organism.
25
What do scientists call it when cells become specialised?
They call it differentiation.
26
Name five ways that a sperm cell is specialised?
- They have a flagellum so that they can swim to an egg.
- They are streamlined to make swimming to an egg more easy
- They contain many energy producing mitochondria so that they can swim to the egg.
- Digestive enzymes in acrosome to break through egg.
- A large nucleus containing half the genetic information needed to make a human.
27
What is the job of a sperm cell?
The job of a sperm cell is to swim to an ovum and fertilise it.
28
What is the job of a nerve cell?
The job of a nerve cell is to send electrical impulses around the body.
29
List four adaptations of a nerve cell.
Four adaptations of a nerve cell are:
- They have lots of dendrites to make connections to other cells.
- They have a very long axon that carries the electrical impulse from one place to another.
- Synapses to pass the impulse between nerve cells.
- Synapses contain lots of mitochondria to provide the energy needed to make special transmitter molecules.
30
What is the job of a muscle cell?
The job of a muscle cell is to contract and relax to allow movement.
31
What is a specialised cell?
It is a cell that has adapted to suit its function.
32
What is the definition of a tissue?
Cells of the same type working together to perform a specific function.
33
What is the definition of an organ?
A structure made from multiple tissue types to perform a specific function.
34
What is the definition of an organ system?
Multiple organs working together to perform a specific function.
35
List three adaptations of a muscle cell that make it a specialised cell.
- Contain special fibres that can slide over one another to allow the fibres to contract.
- Contain lots of mitochondria to provide energy for contraction.
- Store glycogen which can be converted into glucose for respiration.
36
What is the equation for magnification?
Image size/actual size or I/A
37
What is the max magnification of a light microscope?
1500x
38
What are the names of the two types of microscopes?
A light microscope and an electron microscope.
39
What is the max magnification of an electron microscope?
2000000x
40
How do light microscopes form an image?
Using a beam of light.
41
Are light microscopes cheap or expensive?
Light microscopes are relatively cheap.
42
How do electron microscopes form an image?
They form an image using a beam of electrons.
43
What are the names of the two focuses on a microscope?
The coarse focus and the fine focus.
44
How many millimetres are in a centimetre?
There are 10 mm in 1cm.
45
How many micrometres are there in a millimetre?
There are 1000 micrometres in 1 mm.
46
How many micrometres are in a nanometre?
There are 1000 micrometres in a nanometre.
47
How many nanometres are there in a centimetre?
There are 10 million nanometres in a centimetre.
48
Is a light microscope easy or hard to use?
It is easy to use.
49
When was the electron microscope invented?
The electron microscope was invented in the 1930s.
50
What is the definition of diffusion?
Diffusion is the spreading out of particles of a substance from an area of high concentration to an area of low concentration.
51
List three examples of particles that diffuse and when they diffuse.
- Oxygen when it diffuses into the cell for respiration in the mitochondria.
- Carbon dioxide when it is a waste product of respiration it diffuses out of the cell.
- Urea when it is a waste product produced by cells and when it diffuses out of the cell.
52
What is the correct name for the difference in concentration?
The concentration gradient.
53
The *blank* the concentration gradient the *blank* the diffusion takes place.
Greater and faster.
54
Will diffusion take place faster in a hotter or colder temperature?
Diffusion will take place faster in a hotter temperature.
55
Why will diffusion take place faster in a hotter temperature?
Diffusion takes place faster in a hotter temperature because the particles have more kinetic energy.
56
Define "Resolution".
The shortest distance between two points on a specimen that can still be distinguished as two separate entities.
57
Name a thing that can be seen by and electron microscope and not a light microscope.
Sub-cellular structures such as mitochondria and ribosomes.
58
Name the two types of human stem cells.
Embryonic stem cells and adult stem cells.
59
What is made when a sperm cell and an egg cell fertilise?
When an egg cell and a sperm cell fertilise they form what is called a zygote.
60
What happens to the zygote after it has been made?
The zygote then undergoes mitosis and becomes a hallow ball of cells called the embryo.
61
What is the definition of active transport?
Active transport is the movement of particles from a region of low concentration to an area of high concentration. It requires energy called ATP.
62
Give one example of a good exchange surfaces.
Large surface area
63
Define the concentration gradient.
The concentration gradient is the difference in the concentration of a substance between two areas.
64
Give one example of active transport.
Ions such as magnesium diffuse into the root hair cell on a plant via active transport.
65
Is it true that embryonic stem cells can differentiate into any type of specialised cell?
Yes it is true.
66
Define stem cells.
A stem cell is an undifferentiated cell which can give rise to more cells of the same type and can differentiate to form other types of cells.
67
Give one place in the human body where adult stem cells can be found.
In the bone marrow.
68
What is the difference between embryonic and adult stem cells?
Adult stem cells cannot differentiate to form *any* type of cell.
69
What is the genetic material in a Eukaryotic cell?
DNA
70
Give an example of a Prokaryotic cell.
Bacteria
71
Define Eukaryotic cells.
Eukaryotic cells contain their genetic material enclosed in a nucleus.
72
Define a Prokaryotic cell.
A prokaryotic cell is a cell that has its genetic information not enclosed in a membrane bound nucleus. It is also much smaller than a Eukaryotic cell. They only have a singular loop of DNA.
73
Define Osmosis.
Osmosis is the movement of water molecules from an area of high water concentration to an area of low water concentration.
74
Define the term isotonic.
Isotonic is the term used to describe when the concentration of solutes outside is the cell is the same as the inside.
75
What is the equation for magnification?
Size of Image (I) over Real size of object (A)
76
List 3 specialised plant cells.
The root hair cell, the xylem and the phloem.
77
How are root hair cells specialised?
- They have hair like projections to increase the surface area.
- They have a large permanent vacuole that speeds up the movement of water into the cell.
- They have many mitochondria that transfers energy needed for the transport of minerals.
- They also have no chloroplasts as it is not needed under ground.
78
How is the xylem specialised?
- They have very thick walls containing lignin and this provides support to the plant.
- The end walls of the cells have been broken down this means that the cells now form a long tube so water and minerals can flow easily.
79
How is the phloem specialised?
- Phloem vessel cells have no nucleus allowing sugars to move up and down the plant more easily.
- The end walls of the vessel cells have pores called sieve plates allowing sugars to move up and down the plant more easily.
80
What are the names of the two phloem cells?
The phloem vessel cell and the companion cell.
81
What do phloem tubes do?
They carry dissolved sugars up and down the plant.
82
Give 2 examples of active transport in the world.
1) Root hairs on plants absorbing minerals from the soil.
| 2) Sugar molecules being absorbed from a lower concentration in the gut to the blood where the concentration is higher.
83
What is the scientific term for when the concentration of solutes outside the cell is higher than the internal concentration?
Hypertonic.
84
What is the scientific term for when the concentration of solutes inside the cell is higher than the concentration of solutes outside the cell?
Hypotonic.
85
What are two conditions where stem cells can help in treatment?
Paralysis and diabetes.
86
What are stem cells from plant meristems used for?
They are used to produce plant clones quickly and economically for research and agriculture.
87
What are chromosomes made of?
Chromosomes are made of the molecule DNA.
88
Do body cells have pairs of chromosomes?
Yes True
89
How many pairs of chromosomes do human body cells contain?
23 pairs.
90
What is the first stage of the cell cycle by mitosis?
The DNA replicates to form two copies of each chromosome. The cell also grows and copies internal structures such as mitochondria and ribosomes.
91
What takes place in the second stage of Mitosis?
One set of chromosomes is pulled to each end of the cell. The nucleus also divides.
92
What takes place in the third and final stage of mitosis?
The cytoplasm and the cell membrane divide to form two identical cells.
93
What are the 3 functions of mitosis?
1. Mitosis is essential for growth and development of organisms. (eg plants and animals)
2. Mitosis takes place when an organism repairs itself (eg when a broken bone heals) .
3. Mitosis happens during asexual reproduction?
94
What is the difference between mm, µm and nm?
A factor of 1000.
95
By what process do bacterial cells divide?
Binary fission.
96
If provided with enough nutrients and a suitable temperature how often can bacterial cells divide?
Around every 20 minutes.
97
Describe the two ways that bacteria can be grown in a laboratory.
1) In a nutrient broth solution.
| 2) On an agar gel plate/ petri dish.
98
What is a "contaminant"?
An unwanted species of microorganism growing in your culture.
99
Describe the four stages of Binary Fission (the replication of Prokaryotic cells).
1) The circular DNA and plasmid(s) replicate inside the original cell.
2) The cell gets bigger and the circular DNA strands move to opposite 'poles' (ends) of the cell.
3) The cytoplasm begins to divide and new cell walls begin to form.
4) The cytoplasm divides and two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but can have a variable number of copies of the plasmid(s).
100
What should you do with Petri dishes and culture media before use?
Sterilise it at a high temperature to kill contaminants.
101
Give 2 things that help to maximise the rate of binary fission.
1) Warm environment.
| 2) Lots of nutrients.
102
What is the 'mean division time' and what is it used for.
1) The mean division time is just the average amount of time it takes for one bacterial cell to divide into two.
2) It is used to find the number of bacteria in a population.
103
Give the three steps to figure out how many cells a bacteria will have divided in a certain amount of time, and so the number of cells in has produced using the Mean Division Time.
1) Make sure both times are in the same units.
2) Divide the total time that the bacteria are producing cells by the mean division time. This gives you the number of division.
3) Put 2 to the power of the number of divisions to find the number of cells.
104
What is a "culture medium"?
It is a liquid that contains carbohydrates, minerals, proteins and vitamins that they need to grow.
105
How are bacteria usually transferred into the culture in the required practical 'Culturing Microorganisms?
Using an Inoculating Loop.
106
How do we sterilise the inoculating loop?
Using a flame, a Bunsen burner flame.
107
How do we store a petri dish in school?
Upside down with adhesive tape securing the lid.
108
At what temperature are cultures of microorganisms kept and why?
They are kept at 25 degree Celsius or less to avoid harmful pathogens growing.
109
What temperature are microorganisms kept in Industrial conditions?
They are kept at higher temperatures so that they can grow and divide a lot faster.
110
What are three things you could test when creating your own microorganisms?
How good antibiotics, antiseptics or disinfectants are at killing them.
111
Give the three steps of how to make and use an agar plate to grow your own microorganisms.
1) Pour hot agar jelly in a shallow Petri dish.
2) When the jelly's cooled and set transfer microorganisms to the culture medium with inoculating loops or a sterile dropping pipette and spreader.
3) The microorganisms then multiply.
