B1 Flashcards
(51 cards)
1
Q
What is the features of an animal cell?
A
- ribosomes
- cell membrane
- nucleus
- cytoplasm
- mitochondria
2
Q
What is the features of a plant cell?
A
- chloroplast
- nucleus
- mitochondria
- cell wall
- cell membrane
- vacuole
- cytoplasm
- ribosomes
3
Q
What is the features of a bacterial cell?
A
- cytoplasm
- cell wall
- plasmid
- cell membrane
- single DNA loop
- (sometimes) flagellum
4
Q
What’s the function of the nucleus?
A
- contains DNA. Controls the activities of the cell
5
Q
What’s the function of the cytoplasm?
A
- where most chemical reactions happens
6
Q
What’s the function of the mitochondria?
A
- the site of aerobic respiration
7
Q
What’s the function of the cell membrane?
A
- controls which substances entering and leaving the cell
8
Q
What’s the function of the ribosome?
A
- the site of protein synthesis
9
Q
What’s the function of the chloroplast?
A
- where photosynthesis happens
10
Q
What’s the function of the vacuole?
A
- contains cell sap
11
Q
What’s the function of the cell wall?
A
- made of cellulose
- supports and strengthens the cells
12
Q
Compare a plant, animal and bacteria cell
A
ALL THREE HAS:
- cell membrane
- cytoplasm
PLANT AND ANIMAL CELL BOTH HAS:
- nucleus
- mitochondria
- ribosomes
PLANT AND BACTERIA CELL BOTH HAS:
- cell wall
however plant cells also has:
- a vacuole
- and chloroplast
whereas a bacteria cell has:
- plasmid
- single DNA loop
- sometimes flagella
13
Q
What are the key points about eukaryotes?
A
- eukaryotic cells are complex cells
- e.g: animal and plant cells
14
Q
What are the key points about prokaryotes?
A
- prokaryotic cells are more simple
- they do not have a nucleus
- e.g: bacteria cell
15
Q
What are the features on a microscopes?
A
- eyepiece
- coarse adjustment wheel
- fine adjustment wheel
- high & low power objective lens
- stage
- light
16
Q
What does magnification mean?
A
- is how any times bigger an image is compared to an object
17
Q
What does resolution mean?
A
- this is the ability to tell the difference between 2 points on a picture
18
Q
Which microscope was invented first?
A
- the light microscope
19
Q
Why did the invention of the more advanced microscope increase our understanding of cell?
A
- it allowed us to see sub-cellular structures (little parts of cells)
20
Q
How would you know an image was taken with the electron microscope?
A
- it has a higher resolution
- so the image will be much clearer
21
Q
Write the method of using a light microscope
A
- clip the slide onto the stage
- start with the lowest magnification objective lens
- twist the coarse adjustment to move the stage up to just below the objective lens
- move the stage down until the image is roughly in focus
- move the fine adjustment to get a clear image
- get a bigger image by using an objective lens with a higher magnification
22
Q
What makes a diagram ‘good quality’ ?
A
- sharp pencil used
- smooth outlines of the key features - no sketching
- no shading or colouring in
- labelled with lines which don’t cross
- title, scale and magnification are all included
23
Q
What’s the equation for magnification?
A
M = I/A
magnification = image size / actual image
m - mm (x 1000)
mm - m ( / 1000)
mm - µm ( x 1000)
µm - mm (/ 1000)
24
Q
What does undifferentiated mean?
A
the cell is not specialised
- it can turn into any other type cell
25
What does differentiated mean?
- it develops into a specialised cell
| - e.g: a sperm cell or nerve cell
26
What are the 6 specialised cell?
- sperm cell
- nerve cell
- muscle cell
- root hair cell
- xylem
- phloem
27
What is the function and adaptation of a sperm cell?
FUNCTION:
- to swim to the egg
ADAPTATION:
- flagellum (tail)
- mitochondria =release energy
- enzymes in head to help penetrate egg
28
What is the function and adaptation of a nerve cell?
FUNCTION:
- to carry nerve impulses through the body
ADAPTATION:
- long = to carry impulses long distances from CNS to muscles
- insulated with a fatty sheath = speeds up impulses
29
What is the function and adaptation of a muscle cell?
FUNCTION:
- to contract to allow movement
ADAPTATION:
- lots of mitochondria to release energy through respiration
30
What is the function and adaptation of a root hair cell?
FUNCTION:
- absorb water and nutrients from soil
ADAPTATION:
- large surface area and thin walls to speed up the rate of absorption
31
What is the function and adaptation of a xylem?
FUNCTION:
- transports water around the plant
ADAPTATION:
- hollow ends to make a tube for water to travel through
- thick cell walls to help support the plant
32
What is the function and adaptation of a phloem?
FUNCTION:
- transports dissolved sugar and amino acids around the plant
ADAPTATION:
- cells close to the phloem provide energy to transport the substances
33
What is mitosis?
- it is part of the cell cycle, where cells divide
34
What is the purpose of mitosis?
- it is done so organisms can grow and repair themselves
35
What happens to cell during mitosis?
- cells which have divided by mitosis are genetically identical to the parent cell
36
Write the stage of the cell cycle of mitosis
1. the cell grows and increases the number of mitochondria and ribosomes
2. DNA replicates to make 2 copies/clones of each chromosome
3. the DNA lines up down the centre of the cell
4. one set of DNA is pulled to each side of the cell
5. the nucleus divides
6. the cytoplasm and cell membranes divide and two identical cells are formed
37
What is a stem cell?
- it is an undifferentiated cell which can become another type of cell
38
What are 2 sources of stem cells in humans?
- embryos
| - adult stem cells
39
What are the advantages and disadvantages of an embryos?
ADVANTAGES:
- can become most other types of cell
- used to treat disease e.g: diabetes/paralysis
- not rejected by the body
DISADVANTAGES:
- can cause transfer of viruses, ethical issues = embryos are potential life, religious objections (should not 'play God'
40
What are the advantages and disadvantages of an adult stem cells?
ADVANTAGES:
- can form some other types of cells e.g: blood cells from bone marrow
- not rejected by the body
DISADVANTAGES:
- can cause transfer of viruses, can differentiate into fewer types of cells than embryos
41
What is meristem?
- plants also have stem cells - called meristem tissue
42
What can meristem do?
- meristem tissue can differentiate into any other type of plant cell, at any point in the plant’s life
43
What are the advantages of a plant stem cells - meristem tissue?
ADVANTAGES:
- can clone rare plants to stop them from going extinct
- can clone plants which have special features e.g: resistance to a disease or a very nice tasting fruit
44
What is the definition of diffusion?
- the spreading out of the particles from an area of higher concentration to an area of lower concentration
45
List 4 factors that speed up the rate of diffusion
- a big difference in concentrations (large concentration gradient)
- warmer temperature
- large surface area of the membrane
- only a short distance for the substance to diffuse
46
Describe how the gills of a fish and the filaments of an axolotl are adapted for efficient diffusion
FOR BOTH THE GILLS OF A FISH & FILAMENTS OF AN AXOLOTL:
- large surface area = the faster rate of diffusion as more particles as through at once
- a good blood supply to keep a large difference in concentration
- thin walls so the substances do not have to diffuse far
47
List 3 example of diffusion in our bodies or in the bodies of plants
- in alveoli in our lungs
- the villi of our small intestine
- the leaves and roots of plants
48
What is the definition of osmosis?
- is the movement of water molecules of a high concentration of water to a low concentration of water through a partially permeable membrane
49
What is active transport?
- moves substances from a low to a high concentration against the concentration gradient
- this needs energy which comes from respiration
50
Explain 2 examples of active transport
- root hair cells absorb minerals ions which are in a low concentration in the soil. plants need ions for healthy growth
- sugar is absorbed from a low concentration in small intestine, into the blood which has a higher sugar concentration. sugar molecules are used for cell respiration
51
Comparison between diffusion, osmosis and active transport
ALL THREE HAS:
- involves the movement of particle
DIFFUSION AND OSMOSIS BOTH HAS:
- does not need energy (passive process)
- high to low concentration
DIFFUSION AND ACTIVE TRANSPORT BOTH HAS:
- transports substances other than water
OSMOSIS AND ACTIVE TRANSPORT BOTH HAS:
- needs a semi-permeable membrane
HOWEVER DIFFUSION ONLY HAS:
- happens in gills, alveoli and leaves
ALSO OSMOSIS ONLY HAS:
- involves water only
WHEREAS ACTIVE TRANSPORT ONLY HAS:
- needs energy (active process)
- low to high concentration
