Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Science 2024 > B1 > Flashcards

B1 Flashcards

1
Q

Who and when first described cells

A

1665 Robert Hooke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who and when was the first living cell absorbed

A

1674-1683 Anton van Leeuwenhoek first to observe bacteria and protoctista from pond water samples

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Who and when was the first person to observe a nucleus

A

1831 and Robert Brown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who created the universal theory?
What is it?
Who made it?

A

1839-Matthias Schleiden
All plant materials is composed of cells
The scientist credited for theory is Theodor Schwann-he proposed all living things composed of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Who and when was spontaneous generation disproved

A

1861-Louis Pasteur
He disproved as he demonstrated that bacteria will only grow in sterile nutrient broth after exposed to air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Who and when demonstrated evidence for the origin of new cells

A

1852-Robert Ramek observed cell division in animal cells-findings were not accepted at the time
Rudolf Virchow published the findings as his own to show new cells form from existing ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When were light microscopes first developed

A

16th century

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Limitations of light microscopy

A

Lower magnification and resolution compared to others
Maximum magnification of a light microscope is ×1500 +resolution is 200nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Benefits of light microscope

A

Can observe sub-cellular structures/organelles e.g nucleus, mitochondria and chloroplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Resolution definition

A

The ability to distinguish between objects that are close together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do electron microscopy work

A

Use a beam of electrons in a vacuum with a wavelength of less than 1nm to visualise specimen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Advantages of electronic miscroscopy

A

See more detail
Produce images called electron micrograph
Magnification of ×500,000
Higher resolution of 0.1nm
More stains can be used other than methylene blue which is only used for light microscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Magnification calculation

A

Size of image/actual image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many nanometers is in a micrometre

A

1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How many micrometers is in a millimetre

A

1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How many millimetres is in a metre

A

1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a prokaryotic cell

A

Single-celled organisms
Much smaller than eukaryotic
Bacteria cells
DNA is not contained in a nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is in a prokaryotic cell

A

Cell wall, capsule, ribosomes,nucleoid and plasmid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cell wall structure and definition

A

Made of peptidoglycan +protects and supports cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Capsule

A

Slippery layer outside cell wall of some species of bacteria+
Protects the cell and prevents dessication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Ribsomes

A

Smaller than ones in eukaryotic
Consist of two subunits and not surrounded by membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Nucleoid

A

Irregular shape that holds nuclear material without a nuclear membrane + holds genetic material
The Dna forms one circular chromosome
It is where genetic info can be found and controls cells activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Plasmid

A

Small loops of DNA
They carry genes that benefit the survival of organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Function of bacterial cells

A

Transcription proceess- RNA is formed (molecule with long chain of nucleotides) as it is paired with DNA containing a genetic code and when paired the hydrogen bond breaks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the practical for bacterial cells
Gram stain
26
What does gram stain identify
Bacteria that causes infections to enable them to decide most effective treatment
27
What r the two groups of bacteria gram stain can identify
Gram positive and negative
28
How can they tell the difference between both groups
Have different cell wall structures and respond differently to antibiotics
29
What happens during the staining technique
Bacterial smear is violet and safranin Two stains are added to these bacterial If there is a purple stain under the microscope it is positive If there is a pink safranin stain then the bacteria is negative As they have thinner walls and lipid membranes allow ethanol to wash off the purple stain and to retain the pink safranin stain
30
What is a eukaryotic cell
Multi cellular organisms like plants or animals. Complex cells with a nucleus and membrane-bound organelles
31
What is in an animal cell
Plasma membrane, cytoplasm, nucleus, nucleolus, rough ER, smooth ER, Golgi apparatus, vesicles, lysosomes , ribosomes,mitochondria and centrioles
32
Plasma membrane structure and function
Composed of phospholipid bilayer, with proteins embedded in the layer Permeable and regulates the transport of materials in and out of cell Involved in cell signaling
33
Cytoplasm
Thick, gelatinous, semi transparent fluid and maintains cell shape plus stores chemicals needed for the cell for metabolic reactions
34
Nucleus
Largest organelle which has nuclear pores to allow movement of molecules through it Nucleus contains chromatin It controls and regulates cellular activity plus houses genetic material called chromatin, DNA and protein
35
Nucleolus
Dense spherical structure in the middle of the nucleus Makes RNA and ribsomes
36
Rough ER
Network of membrane bound flattened sacs called cisternae studded with ribsomes Protein synthesis takes place on ribsomes and newly synthesised proteins are transported to golgi apparatus
37
Smooth Er
Network of membrane bound flattened sacs called cisternae studded with no ribsomes Responsible for synthesis and transports lipids and carbohydrate Involved in carbohydrate metabolism
38
Golgi apparatus
A stack of membrane bound flattened sacs Newly made proteins received from rough er Modifies them and packages the proteins into vesicles to be transported where needed
39
Vesicles
Small perusal membrane bound sacs with fluid inside Used to transport materials inside the cell and secretory vesicles transport proteins to surface membrane
40
Lysosome
Small spherical membrane bound sacs containing hydrolytic enzymes Break down waste material including old organelles
41
Ribosomes
Attached to rough er/free floating in cell Consist of two sub units and are not surrounded by membrane Protein synthesis occurs
42
Mitochondria
Have two membranes Inner membrane folded to form cristae and central is called the matrix Can be seen as long in shape or spherical depending on the angle Final stages of cellular respiration Aerobic respiration lots of atp energy needed Dna replication Protein synthesis
43
Centrioles
Small tubes I'd protein fibres and form spindle fibres during cell division
44
Function of animal cell
Exocytosis which is the process of vesicles fusing with plasma membrane and secreting contents
45
What is in a plant cell
All cellular components of an animal apart from centrioles. Cell wall, chloroplast, vacuous, tonoplast, amyloplast, plasmodestmata, pits
46
Cell wall plant
Made of cellulose Protects and supports cell
47
Chloroplast
Double membrane filled with fluid stroma Inner membrane has flattened sacs called thylakoids. A stack of thylakoids is called a grana. Grana contains chlorophyll Site of photosynthesis
48
Vacuole
Membrane bound sacs in cytoplasm that contains cell sapphire Maintains turgor to ensure rigid framework
49
Tonoplast
Partially permeable membrane of vacuole Allows small molecules through
50
Amyloplast
Double membrane bound sacs containing starch Responsible for synthesis and storage of starch
51
Plasmodesmata
Microscopic channel which cross the cell wall of plant cells Enables transport and communication between individual plant cells
52
Pits
Pores in cell wall of cytoplasm Allows water to enter and leave xylem vessels
53
What is l dopa
Precursor for dopamine
54
What does l dopa do
Increase dopamine stored in/released by presynaptic neuron
55
What does increase of dopamine lead to
Normal levels of dopamine to stimulate postsynaptic neuron
56
What does gram negative bacteria have
Two double pips membranes S.g Outer celle membrane/ a cell membrane that surrounds the cell wall
57
Due to plaque building up in lumen what happens
Cells in artery wall in response
58
How do vacuoles help photosynthesis
Push chloroplasts to edges Store water Short diffusion for carbon dioxide
59
What's on rough ers surface
Ribsomes
60
What's the difference between sperms and eggs nucleus
Sperms has half chromosomes than egg 23
61
Qhat are myelinated axons and how do they impact conduction
Myelin sheath wrapped around axons which is made out of shwann cells, they are flattened and mainly called lipid membrane. Insulates the axon and prevents loss of ions. As ions can leave an enter the cell, nodes contains ion channels so impulse jumps from node to node so therefore faster transmission than when action potential occurs along the whole length
62
Why are gram negative more resistant than positive
Because they have a larger impermeable cell wall
63
What does penicillin do and for what bacteria
Antibiotics and only works on gram positive bacteria
64
What is the bacteria responsible for mrsa and acn
Examples of positive bacteria whilst those responsible for Lyme disease and pneumonia are examples of gram negative
65
Unicellular and multicellular definitions
Life forms consist of only one cell and life forms rhat are made of many cells
66
What is 4um equivalent to 1mm
0.04mm

Science 2024 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions