Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biology GCSE > Bio topic 1 > Flashcards

Bio topic 1 Flashcards

get a 9

1
Q

what is diffusion

A

Diffusion is the movement of a substance from an area of high concentration to an area of lower concentration

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

what are the 5 structures of an animal cell

A

nucleus: contains genetic material to control a cells activities
cytoplasm: gel-like substance where chemical reactions happen and site of anaerobic respiration (contains enzymes)
cell membrane: holds the cells structure and control what moves in and out of cell
mitochondria: site of aerobic respiration so cells have energy
ribosomes: site of protein-synthesis

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

what are the 8 structures of a plant cell

A

it has:
nucleus: contains genetic material to control a cells activities
cytoplasm: gel-like substance where chemical reactions happen and site of anaerobic respiration (contains enzymes)
cell membrane: holds the cells structure and control what moves in and out of cell
mitochondria: site of aerobic respiration so cells have energy
ribosomes: site of protein-synthesis
but also:
rigid cell wall: strengthens and supports the cell, made of cellulose
permanent vacuole: contains cell sap (solution of salts/sugars)
chloroplast: contains chlorophyll for absorption of light t photosynthesize

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

what three structures differ from plant cells and animal cells

A
  • chloroplast
  • cell wall
  • vacuole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the structures in a normal bacteria cell

A

BACTERIA DO NOT HAVE CHLOROPLAST OR MITOCHONDRIA NOR A NUCLEUS!!!
cytoplasm: gel-like substance where anaerobic respiration and other chemical reactions requiring enzymes happen
cell-membrane: holds cell together and controls what enters and exits
cell-wall: supports and strengthens cell
plasmids: rings of DNA that is NOT enclosed in a nucleus
single strand DNA: controls cells activities

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

what is a prokaryote
+ give examples

A

A prokaryotic cell is a type of cell that does not have a true nucleus or membrane-bound organelles.
e.g: bacteria and Archaea are prokaryotic cells
size: 0.2 μm – 2.0 μm

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

what is a eukaryote
+ give examples

A

A eukaryotic cell contains membrane-bound organelles such as a nucleus, mitochondria.
e.g: protozoa, fungi, plants, and animals.
size: 5 μm – 100 μm

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

what are the main differences of prokaryotes and eukaryotes?

A
  • prokaryotes are smaller than eukaryotes
  • a prokaryote doesn’t have a membrane-bound nucleus
  • prokaryotic cells divide through binary fission whereas eukaryotes go through mitosis
  • prokaryotes don’t have mitochondria or chloroplast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

MICROSCOPY- experiment

A
  • prepare glass/plastic microscope slide
  • place drop of water in middle of clean slide
  • using tweezers peel of epidermal tissue from onion and put it on slide
  • add drop of iodine to stain cell (helps view results)
  • place cover slip on top
  • clip slide onto stage of light microscope
  • look through eyepiece to see results (adjust for clearer view)
  • draw what you see (cell structures) and label them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

equation for magnification

A

image size / actual size

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

what is cell differentiation

A

when a cell changes to become specialised for their job

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

sperm cells function + adaptations

A

its job is to carry male DNA and fertilize egg (female DNA) for reproduction
- has flagellum = helping it swim
- has streamlined head = help it swim
- has lots of mitochondria = energy to swim
- enzymes (acrosomes) at head = digests through eggs cell membrane
- has nucleus = contains 23 chromosomes for fathers DNA

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

nerve cells functions + adaptations

A

carries rapid electrical signals around body

  • have branched connections = connects to others nerves to form networks
  • axons = long fibres to carry electrical impulses around body
  • neurotransmitters = chemicals that crosses between synapses
  • synapses = allows impulses to pass from one nerve cell to another
  • myelin sheath insulates axons to speed up transmission of nerve impulses
  • dendrites = increases SA for other nerve cells to connect to easily
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

muscle cells functions + adaptations

A

contracts and relaxes

  • protein fibres = can change length of muscle ,fibres shorten to contract muscle
  • many mitochondria = energy to contract through aerobic respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Root hair cells function + adaptations

A

absorbs water and minerals for plants
- has root hairs= increases SA for contact to soil water for osmosis and mineral ions through active transport
- thin walls = faster rate of diffusion
- don’t have chloroplast = root hair is underground so it would be ineffective at absorbing light

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

Phloem function + adaptations

A

for translocation: moves food substances that is produced by photosynthesis to where needed in plant (moves both up and down cell) and requires energy

  • sieve plates = pores that allow sugars to move through cells interior helps transport
  • phloem vessel cells has no nucleus and little cytoplasm so dissolved sugars move more effectively
  • companion cells = provides energy for phloem vessel cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

xylem function + adaptations

A

transports water and soluble minerals from the roots up the plant stem and into the leaves

  • Lose their end walls = so the xylem forms a continuous hollow tube for water to flow
  • lignin = strengthen walls to support plant
  • made of dead cells = makes xylem impermeable
  • unidirectional
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are coiled up lengths of DNA called

A

chromosomes
half from mother and father
[there are 23 pairs of chromosomes, so 46 in total]

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

what are the female chromosomes

A

XX

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

what are the male chromosomes

A

XY

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

how is mitosis used to grow and repair damaged cells for two identical cells to original

A

[IPMATC]
interphase = (cell spends majority of time in this phase) chromosomes replicate and the proteins synthesize
prophase = DNA in chromosome its copy condenses to become visible. membrane around nucleus shrinks and disappears
metaphase = Chromosomes and their copies line up in the middle of the cell
anaphase = Chromosomes and their copies are pulled to different ends of the cell
telophase = chromosomes decondense and new membranes form around the chromosomes at each end of the cell to become nuclei of two new cells
cytokinesis = The cell membrane pinches in and eventually divides into two daughter cells.

process makes two identical new daughter cells with same DNA to parent cell

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

how do prokaryotic cells divide through the process of binary fission

A

prokaryotic cells replicate through binary fission
- circular DNA and plasmids replicate
- the cell gets bigger and DNA moves to opposite ends (poles) of cell
- cytoplasm divides and two new daughter cells which have one copy of circular DNA but vary in plasmids

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

how do u find number of bacteria in population

A
  • convert given time into minutes
  • total time stated/time for cell to divide = the number of division
  • then put the number of divisions calculated as a power
    e.g; 2.5 hours x 60 min = 150 min
    150 min / 30 min = 5 divisions
    2^5= 2 x 2 x 2 x 2 x 2 = 32 cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how do u grow (culture) microorganisms in a lab

A
  • bacteria is grown in a culture medium which contains carbohydrates, minerals, proteins, and vitamins for growth
  • the culture medium can be solid agar jelly or a nutrient broth solution
    -bacteria grown on agar plates will form visible colonies or spreads out on surface of the jelly
    [to make an agar plate you pour hot agar jelly into shallow petri dish and once it cools and sets inoculating loops or a sterile dropping pipette with a spreader can transfer microorganism onto jelly]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

in a school lab what temp should microorganism cultures be kept at and why

A

25 degrees C : harmful pathogens can grow above this temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

in industrial work what temp should microorganism cultures be kept at and why

A

incubated at higher temps for increased rate of growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how do u investigate the effect of antibiotics/antiseptics on bacteria’s growth

A

1- place disk soaked in (differing types of antibiotics or differing concentrations) antibiotics on agar plate with space between discs
2- antibiotics diffuses (soaks) into agar jelly
3- as bacteria grows in petri dish, the zone of inhibition forms
(make sure u put a control paper disk to keep test fair)
4- leave plate at 25 degrees C for 48 hors
5- compare the results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how do you avoid contamination in the culturing microorganism experiment

A

sterilisation = clean petri dish by heating it at high temp to kill unwanted microorganisms
sterilise inoculating loop = pass it over hot flame so bacteria isn’t transferred
petri dish should be lightly taped to lid to stop unwanted microorganisms from entering in air
petri dish should be stored upside down = stops drops of condensation falling onto agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how do you calculate the zone of inhibition

A

Area= π x radius^squared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what are stem cells

A

an undifferentiated cell (not yet gone through differentiation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are the two types of stem cells? [humans]

A
  • embryonic stem cells
  • adult stem cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

embryonic stem cells

A

embryonic stem cells come from the early stages of an embryo which is capable of differentiating into any type of body cell

33
Q

adult stem cells

A

these stem cells are taken from adults but cannot differentiate into many differing types of cells:
they are found in the
brain
eyes
blood
heart
liver
bone marrow
skin
muscle

34
Q

what can human stem cells from bone marrow differentiate into and why is this used

A

blood (red blood cells, platelets, phagocytes and lymphocytes)
it can treat:
severe aplastic anaemia (bone marrow failure)
leukaemia – a type of cancer affecting white blood cells
lymphoma – another type of cancer affecting white blood cells
multiple myeloma – cancer affecting cells called plasma cells
certain blood, immune system and metabolic disorders – including sickle cell anaemia, thalassaemia, severe combined immunodeficiency (SCID) and Hurler syndrome

35
Q

what can embryonic stem cells research help with

A

in heart disease
in type 1 diabetes
in cases of multiple sclerosis , which can lead to paralysis
in cases of spinal cord or brain injury, that have led to paralysis
etc…..

36
Q

why are people against stem cell research

A
  • they believe using embryos shouldn’t be used for experimentation as it can potentially be a human life
  • in a lab stem cells can become contaminated and harm a patient #
37
Q

reasons for stem cell research

A
  • can cure diseases (you can get insulin-producing cells to help with diabetes or replacing RBC’s for people with leukaemia)
  • used in therapeutic cloning so patient and embryo have same genetic info so cells aren’t rejected
38
Q

stem cells in plants
+why

A

meristems: cells of the meristem can differentiate to produce all types of plant cells at any time during the life of the plant.
(found close to the tip of the shoot, and the tip of the root)
- used to clone plants quickly and cheaply
- they can clone close to extinct plants to prevent its extinction
- they can grow desired plants that may be disease-resistant or produce high yield

39
Q

what is diffusion

A

is the net movement or particles from an area of high concentration to an area of low down a concentration gradient

40
Q

what effect does a higher concentration gradient have on diffusion

A

the higher the difference in concentrations, the faster the rate of diffusion

41
Q

what effect does temp have of the rate of diffusion

A

the higher the temp, the more kinetic energy a particle has, so the faster the rate of diffusion

42
Q

how do cell membranes use diffusion

A

small molecules can diffuse through the cell membrane (e.g: glucose, O2, amino acids, water)
[a larger surface area of cell membrane = a faster rate of diffusion]

43
Q

examples of big molecules that cant fit through a cell membrane

A
  • proteins
  • starch
44
Q

what is osmosis

A

the net movement of water molecules from an area of high concentration to an area of low concentration through a partially permeable membrane

45
Q

what is the sugar solution experiment [osmosis]

A

control variable = volume of solution, temp, time, type of solution/ sugar used
dependant = mass of potato cylinder
independent variable = concentration of solution

-cut identical mass and size cylinders of potato (control variable)
- get some beakers and pour different concentrations of sucrose (sugar) solution
- make sure you have a controlled test of just water solution
-measure the mass of potato cylinder
- put potato cylinders into solution and leave the beakers for a set amount of time
- then after time is finished take out the potato cylinders, pat dry them with a towel, and measure their masses [dependant variable]
- calculate the percentage change of mass before putting in solution to after
- is a cylinder has increased in mass they have absorbed h2o, but if its mass has decreased then water has been drawn out of the potato

46
Q

what is active transport

A

Active transport is when substances have to be move from a low to a high concentration against a concentration gradient
(process requires energy)

47
Q

how do plant root hair cells take in minerals and water

A

the RHC’s stick out into the soil and is covered in a bunch of microscopic hairs
which gives it a large surface surface area to absorb water and mineral ions using active transport (which requires energy)

48
Q

active transport in humans

A

active transport is used in the gut when there is a lower concentration of nutrients in the gut but a higher concentration of nutrients in the blood
it allows nutrients like glucose to be taken in to the bloodstream where is concentration is already high so it can be transported to the other cells and be used for respiration

49
Q

how do cells use diffusion

A

takes in needed substances and gets rids of waste substances
e.g: o2 and co2 are diffused interchangeably during gas exchange
urea (a waste product formed by breakdown of proteins) diffuses from cells into plasma to be removed from body

50
Q

what are the usual adaptations of an exchange surface

A
  • thin membrane = short distance to diffuse
  • large surface are = fast rate of diffusion
  • lots of blood vessels (in animals)
51
Q

gas exchange in lungs

A

the alveoli in the lungs are specialised to carry out the diffusion of o2 and co2 in and out of the body;
- large surface area = faster rate of diffusion as more surface area in contact with particles
- moist lining = helps dissolve gasses quickly
- thin walls = less distance so quicker diffusion
- lots of capillaries = good blood supply means faster rate of diffusion

52
Q

villi adaptation for exchanging substances

A

in the small intestine that provide a large surface area for the absorption of food.
- large surface area for increased rate of exchanged substances, food absorbed quickly into blood
- Microvilli on the surface of the villus further increase the surface available for absorption
- lots of blood capillaries, so blood constantly moving in them means that a steep concentration gradient
is maintained to increase rate of substance exchanged
- thin surface layer for shorter diffusion distance

53
Q

leaf structure

A

top
1 = waxy cuticle
2 = upper epidermis
3 = palisade mesophyll
4 = spongy mesophyll
5 = lower epidermis [has guard cell and (stomata)]
6 = waxy cuticle
bottom

54
Q

how do gases diffuse in and out of plant cells
+ adaptations

A

gas exchange: Carbon dioxide enters the leaf and oxygen and water vapour leave the plant through the stomata which is opened and closed by guard cells
- has stomata and guard cells to allow substances in and out
- has large surface are for increased contact to air for diffusion
- air spaces in leaf for air to stay in

55
Q

equation for photosynthesis

A

carbon dioxide + water → glucose + oxygen
6 CO2 + 6 H2O → C6H12O6 + 6 O2

56
Q

fish gas exchange

A
  • water enters by fish mouth (o2 is dissolved in the water)
  • water flows over gills
  • lamellae in gills have lots of capillaries
  • the o2 diffuses into capillaries and co2 diffuses out
57
Q

how are fish gills adapted for gas exchange

A

many gill filaments = increased surface area for contact of particles to increase rate of diffusion
lamellae = lots of blood capillaries for increased rate of diffusion

58
Q

simplified mitosis

A

genetic material is replicated
replicated chromosomes are pulled apart to poles of cell
cell membrane pinches in
divides into two = two identical diploid cells

59
Q

simplified meiosis

A

Chromosomes replicate
line up in cell centre
chromosomes pair up
pair swaps section of DNA
cell pulled apart into two
second cell division = forms 4 non-identical haploid gametes

60
Q

osmosis

A

net diffusion of water molecules from dilute (high water potential) to concentrated (lower water potential) through semi-permeable membrane down concentration gradient

61
Q

osmosis practical

A
  • use cork boree to cut three cyllinders out of potato
  • cut them all to 3cm using scalpel
  • measure and record the mass of each using balance
  • set up 3 test tubes with 10cm^3 of one of each (0.5mol/dm3 of sucrose, 0.25mol/dm3 of sucrose and distilled water)
  • place potato piece in each at same time
  • take them out after 24h and pat dry
  • measure new mass
  • calculate percentage change

control: temp of solutions, size of potatos
independant: solutions
dependant: percentage change of mass of potato

62
Q

equation for percentage change

A

[ (final-initial) / initial ] x 100

63
Q

genome

A

entire genetic material of an organism

64
Q

chromosomes

A

x shaped coiled up threads of DNA which are found in nucleus

65
Q

DNA

A

polymers of two coiled up DNA in double helix struc

66
Q

1cm

A

1 x 10^-2 m

67
Q

1mm

A

1 x 10-3

68
Q

1 μm

A

1 x 10^-6

69
Q

1 nm

A

1 x 10^-9

70
Q

what is the role of vacuole

A

filled with cell sap to give plant cell shape

71
Q

how to set up microscope

A
  • clip prepared slide onto stage
  • select lowest power objective lens (4x)
  • turn coarse focusing dial til microscope almost touch slide
  • then slowly turn coarse focusing dial to bring image into focus
  • use fine focusing dial to bring cells into clear focus
  • adjust objective lens to see cell best
  • calculate magnification using

magnification = eyepiece lens x obj lens

72
Q

viewing cheek cell under microscope

A
  • Set up microscope using the lowest power obj lens
  • Wipe cotton bud down the inside of cheek
  • Rub cotton bud with cells on the centre of microscope slide
  • Put 1 drop of methylene blue stain on top of cells on slide
  • Slowly lower the coverslip onto the slide
  • Observe slide under the microscope using low power
  • Then change objective to high power magnification
  • draw observations
73
Q

how to find how many bacteria cells have been made over time

A

total time waited / time for a single cell division = n

then

2 ^n = number of bacteria made

74
Q

therapeutic cloning

A
  • embryo is produced with same genes as parent
  • reduced chance of immune system rejection
  • stem cells can enter patient and differentiate harmlessly to replace cells
75
Q

cloning plant

A
  • take desired plant and cut it into hundred of pieces
  • incubate pieces with plant hormones
  • they grow into identical clones of og plant
76
Q

plant cloning benefits

A

cheap
quick
good for commerce
reduces chance of extinction

77
Q

hypertonic solution

A

has a high concentration of solute

78
Q

plant cell in hypertonic solution

A

cell will shrink (undergoes plasmolysis) as the cell looses water via osmosis
the cell becomes flaccid

79
Q
A

biology GCSE (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions