B1 Cell Biology Flashcards

1
Q

what is a cell

A

The smallest unit of living matter

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2
Q

what organelles are found in plants only

A

chloroplasts, vacuole, cell wall

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3
Q

define the nucleus

A

contain genetic information which control the activities of the cell

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4
Q

define the cytoplasm

A

most chemical reactions take place here(controlled by enzymes)

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5
Q

define the cell membrane

A

controls the movement of substances into an out of a cell

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6
Q

define the mitochondria

A

most energy is released by respiration here

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7
Q

define ribosomes

A

where protein synthesis takes place

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8
Q

define the cell wall

A

strengthens the cell

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9
Q

define chloroplasts

A

contains chlorophyll which absorbs light energy for photosynthesis

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10
Q

define the permanent vacuole

A

filled with cell sap

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11
Q

name 3 advantages of light micropscopes

A

cheep to buy
colour images can be obtained
can view living specimens

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12
Q

name 3 disadvantages of light microscopes

A

limited magnification
depth of field is restricted
limited resoloution

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13
Q

name 3 advantages of electron microscopes

A

high resolution
greater depth of field
high magnification

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14
Q

name 3 disadvantages of electron microscopes

A

expensive to buy
living specimens cannot be obtained
images are black and white

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15
Q

what is the equation for magnification

A

magnifictaion = image size
actual size

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16
Q

define diffusion

A

the movement of substances from and area of high concentration to an area of low concentration down the divsion gradient, it is a passive process

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17
Q

what is a partially permeable membrane

A

where there is space fro a small volume of particles to enter or leave

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18
Q

define active transport

A

the movement of particles from an area of low concentration to and area of high concentration, against the division gradient using energy

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19
Q

define osmosis

A

the diffusion of water from a dilute to a concentrated soloution across a partially permeable membrane passive process

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20
Q

what is the risk assessment for the osmosis RPA 1

A

care should be taken
cutting potato cylinders
using electrical balance in the presence of water

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21
Q

what is the apparatus required for the osmosis RPA 1 (name at least 5 )

A

potato
ruler
10cm3 measuring cylinder
labels boiling tubes
a test tube rack
knife
salt soloution
distilled water

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22
Q

what is the method for the osmosis RPA2

A
  1. cut 3 potato cylinders and make sure the are all the same length
  2. measure and record the mass of each potato cylinder
  3. measure 10cm3 of the 0,5 salt solution and put into the first boiling tube label the boiling tube 0.5m salt
  4. do the same fro all salt solution
  5. add one potato cylinder to each boiling tube
  6. leave the potato cylinders in the boiling tubes overnight in the test tube rack
    7.remove the potato cylinders from the boiling tubes and carefully blot them dry
  7. re-measure the length and mass of each cylinder and record the meaurements on the table
  8. record the results on a graph
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23
Q

define DNA

A

the chemical from which chromosomes are made

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24
Q

genes

A

a small packet of information controlling a characteristic

25
Q

chormesome

A

thread like structures holding genes

26
Q

define mitosis

A

the division of cells to create 2 identical daughter cells

27
Q

what are stem cells

A

undifferentiated cells meaning they have no specific function

28
Q

what are embryonic stem cells

A

cells that can differentiate into any other type of cell

29
Q

what are adult stem cells

A

have limited number of cells they and differentiate into

30
Q

What are sperm cells specialised to do

A

Sperm cells are specialised for reproduction

31
Q

What is the function of a sperm cell

A

To get the male DNA to the female DNA

32
Q

What are two adaptations of a sperm cell

A

There are a lot of mitochondria in the cell to provide the energy it needs
It also carries enzymes in its head to digest through the egg cell membrane

33
Q

What are nerve cells specialised for

A

Nerve cells are specialised for rapid signalling

34
Q

What is the function of a nerve cell

A

To carry electrical signals from one part of the body to another

35
Q

How are nerve cells adapted for their function

A

The cells along the cover more distance and have branched connections at their ends to connect other nerve cells and form a network throughout the body

36
Q

How are muscle cells specialized for their function

A

Muscle cells are specialised for contraction

37
Q

What is the function of a muscle cell

A

To contract quickly

38
Q

How are muscle cells adapted to their function

A

The cells are long so that they have space to contract and they contain lots of mitochondria to generate the energy needed for contraction

39
Q

How are root hair cells specialised for their function

A

Root hair cells are specialised for absorbing water and minerals

40
Q

What is the function of a root hair cell

A

Root hair cells are cells on the surface of plant roots which grow into long hairs that stick out into the soil

41
Q

How are root hair cells adapted to their function

A

They have a large surface area for absorbing water and mineral ions from the soil

42
Q

How are phloem and xylem cells specialized for their function

A

And xylem cells are specialised for transporting substances

43
Q

What is the function of phloem and xylem cells

A

Phloem and Dylan cells formed phloem and xylem tubes which transport substances such as food and water around plants to form the tubes the cells are long and joined end-to-end

44
Q

How are phloem and xylem cells adapted to their function

A

Xylem cells are hollow in the centre and phloem cells have very few subsellular structures so that stuff can flow through them

45
Q

What are the three stages to cell growth and DNA replication

A

Step 1: in his cell that’s not dividing, the DNA is all spread out in Long strings
Step 2: before it divides, the cell has to grow and increase the amount of sub cellular structures such as mitochondria and
Step 3: the cell then duplicates its DNA– so there’s one copy for each new cell. The DNA is copied and forms x shaped chromosomes. Each ‘arm’ of the chromosome is an exact duplicate of the other

46
Q

What are the three stages of mitosis

A

Step 1: the chromosomes line up at the center of the cell and cell fibers pull them apart. The two arms of each chromosome go to opposite ends of the cell
Step two: membranes form around each of the sets of chromosomes. These become the nuclei of the two new cells. The nucleus has divided
Step 3: lastly the cytoplasm and the cell membrane divide full stop the cell has now produced two new daughter cells. The daughter cells contain exactly the same DNA. They are identical. Their DNA is also identical to the parent cell

47
Q

What are the two main stages of the cell cycle

A

DNA replication and mitosis

48
Q

What is the stage of the cell cycle when the cell divides called

A

Mitosis

49
Q

What do multicellular organisms use mitosis for

A

To grow or replace cells that have been damaged

50
Q

How do prokaryotic cells reproduce

A

Binary fission

51
Q

What are the four stages to binary fission

A

Step 1: the circular DNA and plasmids replicate
Step two colon The cell gets bigger and the circular DNA strands move to opposite ends of the cell
Step 3: the cytoplasm begins to divide and new cell walls begin to form
Step 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 plasminants

52
Q

What is differentiation

A

Differentiation is the process by which a cell changes to become specialized for its job

53
Q

What is a stem cell

A

An undifferentiated cell able to divide to produce lots more undifferentiated cell. They can differentiate into different types of cell depending on which instructions they’re given

54
Q

Where are stem cells found

A

Stem cells are found in early human embryos. Adults also have stem cells but they’re only found in certain places like bone marrow

55
Q

How can stem cells be used

A

Medicine uses adult stem cells cure disease. Embryonic stem cells can also be used to replace full p cells in sick people

56
Q

What are some risks of using stem cells

A

Stem cells grown in a lab may become contaminated with a virus which could be passed on to a patient and make them even more unwell

57
Q

What are some reasons why people are red against stem cell research

A

(1) some people are against stem cell research because they feel that human embryos shouldn’t be used for experiments since each one is a potential human life
(2) campaigners for the rights of embryos feel that scientists should concentrate more on finding and developing other sources of stem cells so people could be helped without having to use embryos
(3) in some countries stem cell research is banned, but it’s allowed in the UK as long as it follows strict guidelines

58
Q

What part of a plant can stem cells be found in

A

Meristems