Biology EOY thingy Flashcards
cell structure, cell division, transport in cells, respiration, aseptic technique, microscopy, etc. (106 cards)
1
Q
What is aerobic respiration?
A
the breaking down of glucose using oxygen or smth
2
Q
What is anaerobic respiration?
A
breaking down of glucose without oxygen. In animals, this will produce lactic acid, and in plants and yeast, it can produce ethanol and carbon dioxide.
3
Q
What is respiration used for?
A
active transport, muscle contraction, protein synthesis, maintaining body temperature.
4
Q
What type of reaction is respiration?
A
active. exothermic reaction
5
Q
Where is the site of respiration in a cell?
A
mitochondria
6
Q
What is the formula for aerobic respiration?
A
glucose + oxygen –> carbon dioxide + water (+energy)
7
Q
what is the formula for anaerobic respiration?
A
glucose –> lactic acid (in muscle cells)
glucose –> ethanol + carbon dioxide (in plant and yeast cells)
8
Q
What process makes beer and wine?
A
fermentation
9
Q
what does fermentation do?
A
produces ethanol, which can be useful for making beer or wine.
10
Q
WHy does our breathing rate not slow done as soon as you’re done with exercise?
A
the body needs more oxygen to break down the excess build up of lactic acid from the exercise in the muscles.
11
Q
the chemical
formula for aerobic respiration…?
A
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
12
Q
carbon dioxide turns limewater…?
A
cloudy
13
Q
What is osmosis?
A
the movement of water molecules from an area of low solute concentration to an area of high solute concentration across a partially permeable membrane
14
Q
Is osmosis a passive or active reaction?
A
passive; it doesn’t need energy
15
Q
What is a hypotonic solution?
A
solute concentration is lower than that in the cell
16
Q
What is a hypertonic solution?
A
solute concentration is higher than that in the cell
17
Q
What is an isotonic solution?
A
solute concentration is the same inside and outside of the cell
18
Q
What is lysis?
A
If the solution outside the cell is more dilute than the contents of the cell, water will enter the cell by osmosis. the cell will swell up and may even burst - lysis.
19
Q
What factors affect the rate of osmosis (as well as diffusion) and explain them
A
A greater concentration gradient, increasing the surface area, increasing the temperature, decreasing the diffusion distance
20
Q
What would happen to an animal cell placed in a hypotonic solution? Why?
A
The cell has a higher solute concentration than the solution. Water enters the cell and it bursts.
21
Q
What would happen to an animal cell placed in a hypertonic solution? Why?
A
The cell has a lower solute concentration than the solution. Water leaves the cell and it shrivels.
22
Q
What would happen to an animal cell placed in an isotonic solution? Why?
A
The cell has the same solute concentration as the solution. No net movement of water.
23
Q
What sub cellular structure protects the cell from the effects of osmosis?
A
the cell wall
24
Q
What is a turgid cell?
A
Water enters plant cells by osmosis, causing the cytoplasm to swell and exert pressure on the cell wall. The strength of the cell wall prevents bursting. only in plant cells.
25
What is a flaccid cell?
When water is in short supply the fluid outside the cell will have a higher solute concentration than in the cytoplasm. Water leaves the cell by osmosis. Only happens in plant cells, and its basically normal
26
What is a plasmolysed cell?
If too much water leaves the cell the cytoplasm will pull away from the cell membrane. This is only in plant cells, when water moves out of it
27
What is a crenated cell?
If the solution outside the cell is much more concentrated than inside, water will move out of the cell by osmosis and the cell will shrivel up
28
What is a concentration gradient?
Concentration gradient - the difference in the concentration of a substance between two areas.
29
In diffusion, which way does the substance go in the concentration gradient?
the substances move DOWN the concentration gradient
30
What are the two types of cell division?
meiosis and mitosis
31
Where is the only place active transport can take place?
across a partially permeable membrane
32
Which cells in the plant are adapted to absorb mineral ions?
root hair cells
33
what do root hair cells absorb?
mineral ions and water
34
What are the steps of mitosis and cytokinesis?
DNA condenses to form chromosomes.
Chromosomes line up along the centre of the cells.
Cell fibres pull the two arms of each chromosome to opposite sides (poles) of the cell.
Cytokinesis - the entire cell divides to form two identical daughter cells.
35
What are the three reasons why new cells are required for multicellular organisms like ourselves?
Growth (we need more cells as we grow)
Development (we need new cell types as we develop new tissues)
Repair (we need to replace the cells that we lose each day)
36
What is the cell cycle?
The series of steps that take place as a cell grows and then divides
37
What are the steps of the cell cycle>?
Cellular growth - the cell gets larger and produces more sub-cellular structures, such as mitochondria and ribosomes.
DNA replication - chromosomes duplicate, so that each consists of two arms (copies).
More cell growth.
Mitosis - the DNA divides into two.
Cytokinesis - the cell divides into two.
38
Are the cells created by mitosis genetically identical to each other, or genetically different?
genetically identical
39
When a cell divides by mitosis, how many cells are produced?
2
40
What do we commonly call the cells produced by mitosis?
daughter cells
41
Name the two types of stem cells found in animals.
Adult stem cells
Embryonic stem cells
42
Two key features of stem cells:
They can divide by mitosis to form more cells
They can differentiate into specialised cells
43
what is a stem cell?
an undifferentiated cell, capable of becoming any other cell
44
Where in the body are adult stem cells found?
in the bone marrow
45
What is the main difference between the adult stem cells and the embryonic stem cells?
Adult stem cells can only differentiate into a limited range of specialised cells
embryonic stem cells can specialise into any type of cell
46
Where in plants can you find stem cells?
Meristem tissue on the tips and roots
47
State and explain three features that most exchange surfaces have in common.
permeable so substances are able to pass through, very thin so substances only have to diffues a short distane, large surface area so lots of molecules can pass through at the same time
48
what are specialised cells>
Cells that are adapted to perform a particular function are called specialised cells.
49
State and explain three features of villi that make them good exchange surfaces.
Surfaces are very thin, Substances only have to diffuse a short distance, Surfaces are permeable , Glucose, amino acids, vitamins etc are able to pass through the villi cells, There are lots of villi, and each villi has microvilli, giving a large total surface area and Lots of molecules can diffuse across at the same time
50
Which two of the following cells are adapted to their roles by having a large surface area?
red blood cells and root hair cells
51
what is an exchange surface?
A part of an organism over which substances are exchanged with the environment
52
what is meiosis
this is cell division that produces gametes
53
where are gametes produced?
testes and ovaries.
54
how many cells does meiosis produce>
makes four haploid daughter cells, genetically different to each other
55
where does mitosis happen
in the body cells
56
what is the formula for magnification
Magnification = Image Size / Actual Size
57
how do you work out actual size
image size/magnification
58
how do you work out image size
image size = magnification x actual size
59
where does active transport take place on a concentration gradient?
against the concentration gradient, therefore needs energy
60
where does binary fission happen?
in prokaryotes
61
Which three conditions do bacteria require for fast growth?
moist, warm, plenty of nutrients
62
During binary fission, are the plasmids always split equally between the two new cells?
no
63
When bacteria divide by binary fission, is it an example of asexual reproduction or sexual reproduction?
asexual reproduction
64
Once a bacterial cell has grown and replicated its genetic material, it is ready to divide by binary fission.
Describe the stages of this process.
The two circular strands of DNA move to opposite sides of the cell
A new cell wall forms down the middle of the cell
The two halves pull apart to form two cells
65
Why is iodine solution commonly used as a stain in onion cell microscopy?
it binds to and stains starch
66
What is the aseptic technique practical and the process
pass an inoculating loop through the flame to sterilise it
allow it to cool to avoid any microorganism touching it to be killed
remove the culture bottle lid and pass the neck of the bottle through the flame to sterilise it
glide the inoculating loop through the bacterial culture. this will inoculate the inoculating loop with bacteria
swwep the neck of the bottle through the floame to sterilise again
replace the culture bottle lid to prevent contamination
partially lift the petri dish to prevent the entry of unwanted airborne microorganisms
gently glide the inoculated metal loop overthe surface of the nturient agar in 4 clear strokes.
pass theinoculating loop through the flame to sterilise
repeat three times
tape the petri lid and incubate at 25 degrees below body temperature to ensurepathogenic microorganisms do not grow. incubateupside down to avoid condensation dripping on bacteria,
67
why do you need to incubate the agar plate upside down?
so condensation doesn't drip on the bacteria
68
why do you need to incubate the agar plate at 25 degrees ?
it has to be below body temperature to ensure that any pathogenic microorganisms don't grow
69
why do you have to partially lift the petri dish
so no unwanted airborne organisms get in there
70
what are the hazards with the aseptic technique practical?
there could be contamination, infection of hands, mix up of specimens.
71
what is meant by a culture?
a growth medium containing microorganisms
72
what does total magnification equal?
eyepiece lens magnification x objective lens magnification
73
What is thejob of muscle cells?
helps pump blood and moves the bones of the skeleton
74
what features enableskeletal mucle to do theirjob
made of proteins that can slide over each other, helping themuscle fibres to contract
conatins many mitochondria to transfer energy needed for contraction
store lots of glycogen to be used in cellular energy to transfer the energy needed forthe fibres to contract
75
what is the job of sperm cells?
contains genetic information from the maleparent and swims through the water to reach the egg
76
what features to sperm cells havethat enable it to carry out its function?
its long tail helps the sperm move along the the water
it haslots of mitochondria in its middle section for the tail to work
the acrosome full of digestive enzymes to break through the egg to allow fertilisation
nucleus to pass on the dna
77
what is the job of root hair cells?
helps plants absorb water and mineral ions from the soil
78
what features do plant cells have that enable them to do their job?
they have great extensions increasing the SA:V availablefor the absorption of mineral oins and water to move into the cell
the large permanent vacuole speeds up the movement of water by osmosis from thesoil across the root hair cell
many mitochondria transfers the energy needed for the active transport of mineral ions into the root hair cells
79
what is the job of red blood cells?
supplies oxygen around the body
80
why do we need to carry oxygen around the body/
to porvide oxygen to all the cells to perfom aerboic respiration
81
what features to red blood cells have that help them do their job?
the molecule called haemoglobin bindsthe red blood cell tothe oxygen to transport
they do not have a nucleus, giving more space for the haemoglobin to carry more oxygen
they are a biconcave dusc shape so it give an increased SA for exchange of oxygen?
82
what is the job of nerve cells
transmit electrical impulsesbetween the bodies tissue and the central nervous systemsof animals
83
why does the nerve cell have an important job>
different parts of the body need a way of rapid communication
84
what features do nerve cells have that successfully enable them to do their job?
lots of dendrites to make connections to other nerve cells
they have a long axon enabling to pass the electrical impulse to other nerve cells long distance
they have a synapse so when an electrical impulse hits the end of a nerve it causes the release of some chemicals which diffuse across the gap to the next nerve cell
they have lots of mitochondira releasing emergy from aerobic respiration
85
what is the job of photosynthetic cells?q
carries out photosynthesis in the plant and makes glucose
86
what featuresdo photosynthetic cells have that help them do their job?
they have manychloroplasts that trap the light needed forphotosynthesis
they are tightly packed in the leaves to absorb as much light as possible
they have a large permanent vacuole to keep the cell rigid as a result of osmosis
87
what is the job of xylem cells
transport tissue in plants that carries water and mineral ions from the roots up the stem
88
what features do xylem cells have that help them do their job?
the spirals and rings of lignin in the xylem cells make them very strong and help them withstand the pressure of water moving up the plant
they form dead hollow tubes built in spirals that allow water and mineral ions to move easily through the plant
89
what is thejob of phloemcells
specialised transport tissue that carries the dissolved sugars around the body of the plant
90
what adaptations do phloem cells have?
the cell walls between cells breaks down to form special sieve plates allows water carrrying dissolved food to move freely up anddown the tubes to where it is needed
they have few organelles so more space is available for dissolved sugars
companion cells have lots of mitochondria to transfer the energy needed to move the dissolved sugars
90
Homologous
describes a matching pair of chromosomes
91
what is a gamete
a sex cell which contains half the DNA of the organism
91
describes a matching pair of chromosomes
Homologous
92
an organism where both alleles for a given trait are the same
Homozygous
93
Homozygous
an organism where both alleles for a given trait are the same
94
Heterozygous
an organism where the alleles for a given trait are different
95
an organism where the alleles for a given trait are different
Heterozygous
96
somatic
body cell (diploid - conatins pair of chromosomes)
97
amino acids?
these are the small molecules that all proteins are made up of
98
these are the small molecules that all proteins are made up of
amino acids
99
genotype
your genetic makeup
100
your genetic makeup
genotype
101
phenotype
the physical way in which genetic information is expressed (the way that you look)
102
what are chromosomes
a thread like structure on which dna and proteins are found
.
103
what is a gene
a gene is a small section of dna that codes for a particular sequence of amino acids which make a sppecific protein
104
what are the different forms of a gene called
alleles
