Unit 1- cell biology Flashcards
(94 cards)
1
Q
Where is dna stored in bacteria cell
A
Plasmids
2
Q
Magnification equation
A
Image size / real size
3
Q
What is differentiation
A
When a cell becomes specialised for its job
4
Q
Function of nerve cell
A
Carry electrical signals from one part of body to another
5
Q
Function of muscle cell
A
To contract quickly
6
Q
Function of root hair cell
A
Absorb water and minerals
7
Q
Function of phloem and xylem
A
Transport substances such as food and water around plants
8
Q
What is a stem cell
A
Undifferentiated cell
9
Q
Where are adult stem cells found
A
Bone marrow
10
Q
What may stem cells be able to do
A
Cure disease, replace faulty cells
11
Q
Where are plant stem cells found
A
Meristem
12
Q
What is mitosis
A
DNA is copied the cell then divides and produces two new daughter nuclei with exact same dna
13
Q
What cells does mitosis take place
A
Eukaryotic cells
14
Q
Why can embryonic stem cells treat more disorders that adult stem cells
A
Embryonic stem cells can develop into any stem cells although adult stem cells can only develop into particular ones
15
Q
What is osmosis
A
Movement of water across partially permeable membrane from a dilute solution to a concentrated solution
16
Q
What is diffusion
A
Spreading out of particles from high to low concentration
17
Q
What is a partially permeable membrane
A
One with very small holes in it so only water can pass through
18
Q
What is active transport
A
Substances (minerals )absorbed from a low to high concentration, needs energy from respiration to work
19
Q
Where does active transport take place
A
Used in the gut and in root hair cells
20
Q
How are exchange surfaces adapted to maximise effectiveness
A
Thin walls
Large surface area
Good blood supply
21
Q
Where does plant diffusion take place
A
Stomata
22
Q
What is the cell cycle
A
Makes cells for growth development and repair
23
Q
Centimetres to micrometers
A
x 10,000
24
Q
Similarities with eukaryotic and prokaryotic
A
Both contain chloroplasts
Both contain genetic material
25
Differences between prokaryotic and eukaryotic
Prokaryotic have no nucleus
Prokaryotic have plasmids
Prokaryotic are smaller
26
One type of cell in a potato that does not contain chloroplasts
Root hair cell
27
Why did the potato piece salt solution decreased in mass
Water moved out of cell by osmosis
Because solution in potato is less concentrated than outside
28
Why is the cover slip at an angle for microscope RPA
To prevent air bubbles
29
How does mitosis form 2 genetically identical cells
Chromosomes pulled apart
DNA is copied
Two new nuclei form
Set of chromosomes are identical to one another
30
Cell that doesn’t contain nucleus
Bacteria, prokaryote , xylem
31
Reason for reduced number of deaths of malaria this year
Improved health care
32
Describe the transport of water through a plant from the roots to atmosphere
-water is transported in xylem
-water evaporates from leaves
-through stomata
33
Two reasons why water loss increased
It was warmer
It was windier
34
Evaluate use of mechanical and biological heart replacements
Mechanical:
-last longer
-bloods clots more likely
-have to take anti clotting medication
-medication can lead to excessive bleeding
-low percentage of deaths due to heart related problems
Biological :
-no medication required
-ethical issues
-valve may harden
-more likely to be rejected
- likely to need further operation
35
Explain how diabetes can cause the body to lose more water
Blood is more concentrated
So water moves out of cell by osmosis
Water moves across partially permeable membrane
36
How is small intestine adapted for absorption
-Villi provide large surface area to volume ratio
-capillaries are thin for short absorption distance
-small intestine is very long
-good blood supply to maintain concentration gradient
-cells have many mitochondria for aerobic respiration for active transport
37
Define double circulatory system
-Blood is pumped to the lungs by right side of the heart
And
-blood is pumped to the body by left side of heart
38
Why does only having on ventricle make circulatory less efficient than having two ventricles
Oxygenated and deoxygenated blood mix
So less oxygen reaches body
39
One condition that could be treated by regenerated human tissue
Paralysis
40
Which part of microscope is used to change magnification
The objective lense
41
Function of cell membrane
Determine what goes in and our of cell
42
Function of cell wall
Important for structure
43
Function of cytoplasm
Where most chemical reactions take place in the cell
44
Function of nucleus
Where dna is stored
45
Differences between plant cell and animal cell
Plant cell contains cell wall, vacuole and chloroplasts and animal cell doesn’t
46
Main different characteristics of a bacterial cell
Contains a flagellum which helps assist the cell in movement
47
Name the blood vessel that carries blood towards heart
Vein
48
What is a eukaryotic cell
Contain their genetic material enclosed in a cell examples include animal and plant cells
49
What is a prokaryotic cell
The genetic material is not enclosed in a nucleus (examples include bacterial cell)
50
What is the size of a typical human cell
10-20 micrometers
51
Centimetres to nanometers
x10,000,000
52
Function of mitochondria
Where aerobic respiration occurs
53
Function of sperm cell
Join with an egg cell (fertilisation)
54
How are sperm cells adapted
Long tail which allows them to swim to the ovum
They are also streamlined to make this easier
Lots of mitochondria to produce lots of energy needed to swim
Contain enzymes which allow them to digest their way through the outer layer of the ovum
55
Adaptations of a nerve cell
Axon carries the electrical pulses from one part of the body to another
End of action synopses which allows impulses to jump from one nerve cell to another
Dendrites which increase the surface area so that other nerve cells can connect easier
56
Adaptations of a muscle cell
-contain protein fibres which can change their length
-packed with mitochondria to provide energy for muscle contraction
-work together to form muscle tissue
57
Function of a vacuole
Filled with cell sap to help keep the cell turgid
58
Adaptation of a root hair cell
Hairs help increase the surface area so can absorb water and minerals more effectively
Do not contain chloroplasts
59
Why cant a root hair cell photosynthesise
Don’t contain chloroplasts because they are underground so sunlight doesn’t reach them
60
Where are xylem cells found in the plant
In the plant stem
61
Adaptations of a xylem cell
Thick walls containing lignin which provides the plant support
Made of dead cells
No nucleus, cytoplasm, vacuole or chloroplasts
Hollow
62
Adaptations of a phloem cell
No nucleus and limited cytoplasm
Cell walls between he cells break down to form special sieve plates, these allow water carrying dissolved food to move freely up and down tubes to where it is needed
Have pores in the end of walls, so dissolved sugars contents can move from cell to cell
Made of living cells
63
What is binary fission
One bacterial cell splits into two bacterial cell
Bacteria can carry out binary fission once every 20 minutes as long as there is enough nutrients and the temp is suitable
64
How to calculate number of bacteria produced during binary fission
Number of bacteria = 2 to the power of the number of rounds of division
65
Functions of mitosis
1. Essential for growth and development of multicellular organisms (plants and animals)
2. Mitosis takes place when an organism repairs itself (when a broken bone heals)
66
Name of a cell that has not differentiated
Early embryonic cell
67
Bits of equipment used to prepare cell for magnification
A slide, dye
68
Features of a red blood cell
Has no nucleus
No cell wall
Biconcave
Contains haemoglobin
no chloroplasts
No vacuole
Contains cytoplasm, cell membrane
69
What is human body temperature
37 degrees
70
How to calculate total magnification
Magnification of eye piece x magnification of objective lens
71
How to create magnification scale
Place clear ruler over stage
Measure diameter of field of view
Show this on our drawing using a scale bar
72
How do you avoid contamination when making agar plate
1. Sterilise all pétri dishes
2. Pass incubating loop through Bunsen Burner
3. Attach lid using adhesive tape to stop microorganisms from entering
73
What do you call the region where bacteria has not grown
Zone of inhibition
74
What are bacteria transferred using in the bacteria RPA
Inoculating loop
75
What temperature should we incubate bacteria in school and why not at 37 like in labs
25 degrees as this reduces chance that harmful bacteria will grow, 37 degrees is human body temperature so it will grow best then
76
How to work out zone of inhibition
Pi x R squared
77
Why is distilled water used not tap water in osmosis RPA
Distilled water no other substances as they could affect the rate of osmosis
78
What is a cork borer used for in osmosis RPA
To make all the cylinders the same diameter
79
Grams to milligrams
X1000
80
Advantages of sexual reproduction
-Produces variation in the offspring
-The species can adapt to new environments due to variation, which gives them a survival advantage
-A disease is less likely to affect all the individuals in a population
81
What is asexual reproduction
Only one parent is needed in asexual reproduction
There is no fusion of gametes so genetic material does not mix
82
What is sexual reproduction
Two parents are needed in sexual reproduction
During this process the nuclei of the male and female gametes are fused in order to create a zygote. This process is known as fertilisation
83
Advantages of asexual reproduction
-the population can increase rapidly when the conditions are favourable
-only one parent is needed
-it is more time and energy efficient as you don't need a mate
-it is faster than sexual reproduction
84
Disadvantages of sexual reproduction
-time and energy are needed to find a mate
-it is not possible for an isolated individual
85
Disadvantages of asexual reproduction
-it does not lead to variation in a population
-the species may only be suited to one habitat
-disease may affect all the individuals in a population
86
Differences between asexual and sexual
Sexual involves fertilisation, asexual does not
Sexual requires more energy, asexual does not
Sexual is slower, asexual is faster
87
Why does red blood cell burst but plant cell does not
Water has entered cell by osmosis however plants cell has cell wall which prevents it from bursting
88
Differences between process of mitosis and meiosis
Mitosis produces 2 daughter cells but meiosis produces 4 daughter cells
One cell division in mitosis but 2 in meiosis
Meiosis produces haploid cells mitosis forms diploid cells
89
Similarly between meiosis and mitosis
Both copy DNA
90
What is therapeutic cloning
-an embryo is produced with the same genes as the patient
-stem cells from the embryo are not rejected by the patients body so they may be used for medical treatment
-risks such as transfer of viral infection and some ethical or religious objections
91
What can plant stem cells do
-can be cloned quickly and economically so :
-rare species can be cloned to protect from extinction
-crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers
92
Factors which affect the rate of diffusion
-the difference in concentrations
-the temperature
-the surface area of the membrane
93
What happens if solution outside cell becomes more dilute (higher water concentration and lower concentration of sugar)
Water will move out by osmosis
The cell will swell and may burst
94
What happens if solution outside celle become more concentrated (low concentration of water high concentration of sugar)
Water will move out of the cell by osmosis
Cytoplasm will become too concentrated and cell will shrivel and can no longer survive
