B2 Full Flashcards

?
  • Created by: Madisonxo
  • Created on: 24-04-17 21:46
B2 - Topic one
The building blocks of cells
1 of 146
Features of an animal cell?
Cell membrane, Cytoplasm, Mitochondria, Nucleus
2 of 146
What does the Cell membrane do?
Controls which substances enter and leave the cell.
3 of 146
What happens in the cytoplasm?
Many of the chemical reactions needed to carry out life processes happen here.
4 of 146
What is the function of the nucleus?
The nucleus contains the DNA and controls all of the activities of the cell.
5 of 146
What is the function of the mitochondria?
The mitochondria is the powerhouse of the cell - creates energy by respiration.
6 of 146
Features of plant cells?
Vacuole, Chloroplasts, Nucleus, Mitochondria, Cell membrane and Cell wall
7 of 146
Function of the cell wall?
Made of tough cellulose - to support cell and allow it to keep its shape.
8 of 146
Function of chloroplasts?
Contain chlorophyll - green substance that absorbs light energy which is used in photosynthesis.
9 of 146
Function of vacuole?
Central gap in the cytoplasm - supports the plant by keeping the cells rigid as it is filled with sap.
10 of 146
Features of a bacterium cell?
Cytoplasm, Cell wall, Plasmid DNA, Bacterial (Chromosomal) DNA and sometimes flagella. IMPORTANT - NO NUCLEUS
11 of 146
Function of chromosomal DNA?
Contains the genetic information for the cells.
12 of 146
Function of Plasmid DNA?
Contains extra information such as defense mechanisms.
13 of 146
Function of Flagella?
Helps the cell to move.
14 of 146
Difference between Chromosomal DNA and Plasmid DNA?
Chromosomal DNA = Giant loop of DNA containing most of the genetic information. Plasmid DNA = Small loops carrying extra information.
15 of 146
Length of the magnified object =?
Length of the magnified object = Length of the object x Magnification
16 of 146
What is a gene?
A section of DNA that codes for a particular protein/characteristic. (e.g. hair colour)
17 of 146
What is a chromosome?
Thread-like structure found in the nucleus of a cell which carries genetic information. The human cell nucleus contains 23 pairs of chromosomes.
18 of 146
What is DNA?
Deoxyribonucleic Acid - Makes up genes and chromosomes and are the instructions for the cell growth and activity.
19 of 146
Describe the structure of DNA
Double helix, made up of 4 bases which hold the strands together with weak hydrogen bonds.
20 of 146
What are the 4 bases in DNA?
Adenine, Thymine, Cytosine, Guanine.
21 of 146
Mnemonic for base pairs?
Apple Tart, Chocolate Gatau
22 of 146
What do the bases represent?
The order in which amino acids are assembled to make specific proteins.
23 of 146
What is a complementary base pair?
A matching base.
24 of 146
DNA discovery, key names: M------ W------ and R------- F-------
Maurice Wilkins and Rosalind Franklin
25 of 146
How did Wilkins and Franklin help further the discovery of DNA?
They studied the structure of DNA using X-Rays, X-Ray beams were directed at DNA and photos were taken, from the patterns Rosalind could work out how groups of atoms in DNA were arranged.
26 of 146
DNA discovery, key names: J---- W----- and F------ C----
James Watson and Francis Crick.
27 of 146
How did Watson and Francis help further the discovery of DNA?
Watson and Francis tried to build a 3D molecular model of DNA using info from other scientists. Wilkins showed them some of the X-Ray photos without Franklin's permission. Using her images, Watson and Crick were able to build the model.
28 of 146
When was the Human Genome Project launched?
1990
29 of 146
What is the Human Genome Project?
A project which aimed to map the genetic make up of the human race and includes work from scientists in 18 countries.
30 of 146
Benefits of the Human Genome project?
1) Improved genetic testing 2) Improved predictions and screenings of inherited diseases 3) New gene therapy treatments 4) New knowledge of how genes change
31 of 146
What is genetic engineering?
Genetic engineering is when scientists take a gene from one organism and insert it into the DNA of another organism.
32 of 146
Describe insulin genetic engineering - step one
Restriction enzymes cut out the insulin gene from a human chromosome.
33 of 146
Describe insulin genetic engineering - step two
The restriction enzymes also cut open a plasmid and the insulin gene is inserted. The insulin gene is stuck in place by ligase enzymes.
34 of 146
Describe insulin genetic engineering - step three
The modified plasmid is inserted into a bacterium cell which starts to rapidly divide. While it divides, the plasmid is replicated making millions instructed to produce insulin.
35 of 146
In Mitosis, describe the daughter cells at the end of the process
Each daughter cell has the same number of chromosomes and genetic information as the parent.
36 of 146
In Meiosis, describe the daughter cells at the end of the process
Each daughter cell has half the number of chromosomes of the parent.
37 of 146
What does mitosis produce?
Two diploid cells. Cells with identical numbers of chromosomes and genetic information (clones)
38 of 146
What does Meiosis produce?
Four haploid cells. Copied of genetic information are made then the cell divides twice (forming four daughter cells). Daughter cells have half the number of chromosomes of the parent
39 of 146
Define Diploid
A cell containing two complete sets of chromosomes - one from each parent.
40 of 146
Define haploid
A cell containing half the usual number of chromosomes.
41 of 146
Use of mitosis?
Growth and repair of cells, asexual reproduction.
42 of 146
Use of meiosis?
Used to produce haploid gametes for sexual reproduction.
43 of 146
What do gametes contain?
23 chromosomes each.
44 of 146
What happens to gametes during fertilisation?
Gametes fuse together to make a single cell called a zygote.
45 of 146
What does a zygote contain and what does it do?
36 chromosomes and continues to grow through mitosis.
46 of 146
Meaning of gamete?
Sex cells produced in the male and female reproductive systems.
47 of 146
Cloning - step one
The body cell is removed from the person being cloned and the nucleus taken out.
48 of 146
Cloning - step two
An egg cell is taken from a donor and the nucleus taken out making an enucleated cell.
49 of 146
Cloning - step three
The body cell nucleus is put into the enucleated egg cell.
50 of 146
Cloning - step four
The cell is stimulated and starts to divide forming an embryo.
51 of 146
Cloning - step five
The embryo is implanted into the womb of a surrogate mother who will give birth to the clone.
52 of 146
Pros of cloning?
1) If an organism has desirable characteristics, such as a cow that produces rich milk, it's worth cloning. 2) Some individuals have genetically engineered traits and cloning can guarantee the offspring get the same trait.
53 of 146
Cons of cloning?
1) It’s difficult to clone animals and takes many attempts since not all embryos develop successfully. 2) Animals that are cloned seem to die younger or catch diseases quickly.
54 of 146
What is a specialised cell?
During the development of a multi-celled organism, cells differentiate to form specialised cells.
55 of 146
What is a stem cell?
A Stem cell is a cell that hasn’t yet become specialised and can be found in embryos or bone marrow. These can be used to treat certain conditions but the use of these cells is ethically controversial.
56 of 146
Differences between Embryonic stem cells and adult stem cells?
Embryonic Stem cells have the ability to develop into any kind of cell, whereas adult stem cells can only develop into specific cells such as red blood cells.
57 of 146
Making protein - step one
DNA unravels and a copy of one strand is made.
58 of 146
Making protein - step two
The strand copy is made to produce mRNA.
59 of 146
Making protein - step three
The copy (with its code) then moves towards the ribosome.
60 of 146
Making protein - step four
The ribosome decodes the code which tells the ribosome how to make the specific amino acid.
61 of 146
Making protein - step five
Amino acids are then joined together to form a polypepide.
62 of 146
Are mutations in the DNA harmful, beneficial or neutral?
All three.
63 of 146
What can mutations cause?
Different amino acids forming (and in turn different proteins forming).
64 of 146
What are enzymes?
A biological catalyst, it is a protein molecule made from long chains of amino acids. These molecules are folded to create a specific shape.
65 of 146
What is an Active Site?
An active site is a part of the enzyme where the substrate molecule can fit into it, it is where the chemical reactions take place.
66 of 146
What does denatured mean?
When an enzyme shape is destroyed by high temperatures or the wrong pH level.
67 of 146
What is an optimum?
An optimum is the best settings for an enzyme to exist - optimum temperature, optimum pH - e.g. protease (enzyme found in the stomach) has an optimum pH of 2 as it is found in the stomach (which is acidic).
68 of 146
Topic 2
Organisms and Energy
69 of 146
What is diffusion?
Diffusion is when something travels from an area of high concentration to an area of low concentration down a concentration gradient.
70 of 146
How does oxygen pass into cells?
Diffusion.
71 of 146
Equation for aerobic respiration?
Glucose + Oxygen ----> Water + Carbon dioxide + Energy
72 of 146
What happens during exercise to your heart rate, breathing rate and your arteries?
Both your heart rate and breathing rate increase, the arteries supplying muscles dilate.
73 of 146
Equation for cardiac output?
Cardiac output = Heart rate x Stroke Volume
74 of 146
What is anaerobic respiration?
When energy is created with lack of oxygen.
75 of 146
Equation for anaerobic respiration?
Glucose ---> lactic acid + energy
76 of 146
What happens when lactic acid is produced?
Lactic acid builds up in the muscles causing fatigue, cramps in the muscles and EPOC.
77 of 146
What is EPOC?
Excess Post Oxygen Consumption - breathing and heart rate remains high after exercise.
78 of 146
In photosynthesis, where does water travel?
Up from the roots.
79 of 146
What does sunlight provide the plant with?
The plant energy.
80 of 146
How do plants take in carbon dioxide?
Carbon dioxide enters the leaf through small holes on the underneath.
81 of 146
Where do chemical reactions take place in plants during photosynthesis?
The chlorophyll.
82 of 146
Photosynthesis equation?
Carbon dioxide + water ---> Glucose + oxygen
83 of 146
How is the glucose produced in photosynthesis used?
It is used by the plant for energy (through respiration).
84 of 146
Name sections of the structure of a leaf
Cuticle, upper epidermis, Palisade layer, Vein, lower epidermis, Spongy layer, Stomata
85 of 146
Define limiting factors
Factors that could limit the rate of photosynthesis.
86 of 146
What are the 3 limiting factors?
Temperature, CO2 and Light.
87 of 146
On the graph of carbon dioxide and light (photosynthesis) factors, if the graph has risen and stayed a constant line what does this mean?
Photosynthesis increases at first but is then limited by lack of increase in temp/light/CO2 (depending on the graph) e.g. if it is a CO2 graph, the limiting factors are light or temp.
88 of 146
Steps of transpiration?
1) Water evaporates through the stomata 2) Water passes back into the leaf 3) Water is pulled upwards 4) This is replaced by water 5) Water enters root hair cells replacing the water lost through respiration.
89 of 146
How does water pass back into the leaf?
Through xylem vessels by osmosis.
90 of 146
How is water pulled upwards?
Through the xylem tissue.
91 of 146
How is the water that has been pulled upwards replaced?
By water entering from root tissues
92 of 146
How does water enter the root hair cells?
By osmosis
93 of 146
What is active transport?
When dissolved molecules move across a cell membrane from a lower to a higher concentration - particles move against the concentration gradient and therefore require an input of energy from the cell.
94 of 146
What is osmosis?
Osmosis is when water diffuses from a high concentration to a low concentration through a partially permeable membrane.
95 of 146
Topic 3
Common Systems
96 of 146
How are Fossil Records useful?
Fossil Records are useful ways to record and observe a particular species development.
97 of 146
Why are there gaps in the fossil record?
1) some fossils are yet to be found 2) Some are easily destroyed 3) Environmental conditions can drastically slow down the decaying process.
98 of 146
What is the Pentadactyl limb?
It is the five-fingered bone structure that is found in most vertebrates.
99 of 146
How does the Pentadactyl limb support the theory of Evolution?
As it suggests that species all come from the same ancestor.
100 of 146
How do plants grow (in terms of cells)?
1) Their cells divide through mitosis and each cell grows through elongation. 2) Cells specialise into root hair cells, palisade cells etc.
101 of 146
How do humans grow? (in terms of cells)
1) By cell division through mitosis and cells becoming specialised. 2) Animal stem cells differentiate to form specialised cells
102 of 146
Who grows for the longest, plants or animals?
Plants do not stop growing, humans stop growing once the become adults.
103 of 146
Name the four parts of the blood
1) Red Blood cells 2) Plasma 3) White blood cells 4) Platelets
104 of 146
Use of the red blood cells and description of their structure
Contain haemoglobin and carry oxygen around the body. They have no nucleus and have a large surface area.
105 of 146
Use of the plasma and description of their structure
Carry around the other 3 parts of the blood. It transports Carbon dioxide and Glucose as well as taking away waste products to the Kidneys.
106 of 146
Use of the white blood cells and description of their structure
Kills invading Microbes by producing Antibodies or engulfing the microbe.
107 of 146
Use of the platelets and description of their structure
Small bits of cells that lie around waiting for a cut to appear so they can clot to form a scab which stops harmful microorganisms getting into the body.
108 of 146
Define tissue
A group of cells make up a tissue.
109 of 146
Define organ
A group of tissues make up an organ
110 of 146
Define a system
A group of organs make up a system
111 of 146
Define an organism
A group of systems make up an organism
112 of 146
What is the circulatory system responsible for?
Pumping blood around the body.
113 of 146
What are the main organs in the circulatory system?
The heart, lungs and kidneys.
114 of 146
How does deoxygenated blood enter the heart?
Through the vena cava into the right atrium.
115 of 146
Where does the blood go when pumped from the right atrium?
It is pumped through the valves and into the right ventricle.
116 of 146
Where does the blood go from the right ventricle?
It is pumped through valves up to the lungs via the pulmonary artery to be oxygenated.
117 of 146
How does oxygenated blood enter the heart?
It enters from the lungs through the pulmonary vein into the left atrium.
118 of 146
Where does the oxygenated blood go from the left atrium?
It is pumped through even more valves to the left ventricle.
119 of 146
Where is the oxygenated blood pumped lastly?
Out of the aorta to the rest of the body to supply the muscles with oxygenated blood.
120 of 146
What is the double circulatory system?
Two loops in our body in which blood circulates. One is oxygenated and the other is deoxygenated.
121 of 146
How is oxyhaemoglobin formed?
When haemoglobin binds with oxygen, oxyhaemoglobin is formed. This happens when blood is pumped from the heart to the lungs as it picks up oxygen.
122 of 146
Why does the heart pump blood to the intestine?
To remove oxygen and glucose from the blood, oxyhaemoglobin is then split up into oxygen and haemoglobin.
123 of 146
What does an artery do?
Carries high pressure blood away from the heart, have thick muscular walls, small blood passageways and no valves.
124 of 146
What does a vein do?
Carry low pressure blood back into the heart, have thin walls and have valves to prevent backflow of blood.
125 of 146
What does a capillary do?
Found in muscles and lungs, one cell thick, very low blood pressure, connects arteries to veins and is where gas exchange takes place.
126 of 146
Name the parts of the digestive system
Mouth, Oesophagus, Stomach, Small intestine, Pancreas, Large intestine, Anus, Liver, Gall bladder
127 of 146
Function of the mouth?
Where food is chewed to start breaking it down - amylase is added.
128 of 146
Function of the oesophagus?
A tube which uses muscle contractions to push food down
129 of 146
Function of the stomach?
Churns food up and mixes with hydrochloric acid to kill bacteria
130 of 146
Function of the small intestine?
Where digested food is absorbed by villi and moved along by peristalsis.
131 of 146
Function of the pancreas?
Where enzymes are made and released into the small intestine.
132 of 146
Function of the large intestine
Where water is diffused into the blood undigested food is passed making faeces.
133 of 146
Function of the anus?
Where waste is passed out of the body.
134 of 146
Function of the liver?
Where bile is produced to help the digestion of fats.
135 of 146
Function of the gall bladder?
Where bile is stored.
136 of 146
What happens when enzymes contact food during digestion?
When they come into contact and react with food they break it down into smaller pieces which can then pass into the blood.
137 of 146
What does Carbohydrase do?
It is produced in the mouth, pancreas and small intestine and breaks starch down into glucose.
138 of 146
What does Protease do?
Produced in the stomach, pancreas and small intestine - breaks proteins down into amino acids
139 of 146
What does lipase do?
Produced in stomach and small intestine - breaks down lipids into fatty acids and glycerol.
140 of 146
What is bile and where is it produced?
It is a chemical produced in the liver and stored in the gall bladder.
141 of 146
What does bile do?
1) It neutralises stomach acid and produces alkaline conditions for enzymes to work it 2) it emulsifies fats
142 of 146
What happens to smaller food molecules in the intestine?
They diffuse into the blood through villi.
143 of 146
What are probiotics?
Food that contain live bacteria and produce lactic acid in the gut. They may be able to improve the health of your digestive system.
144 of 146
What are Prebiotics?
They are substances that can’t be digested by human digestive enzymes but act as food for probotic bacteria in the small intestine.
145 of 146
What are plant stanol esters?
They are substances found in plants that appear to lower blood cholesterol in people.
146 of 146

Other cards in this set

Card 2

Front

Features of an animal cell?

Back

Cell membrane, Cytoplasm, Mitochondria, Nucleus

Card 3

Front

What does the Cell membrane do?

Back

Preview of the front of card 3

Card 4

Front

What happens in the cytoplasm?

Back

Preview of the front of card 4

Card 5

Front

What is the function of the nucleus?

Back

Preview of the front of card 5
View more cards

Comments

Irenebinil

Report

could someone please try and keep crossword answers in words rather than long sentences

Similar Biology resources:

See all Biology resources »See all B2 resources »