quick definitions Flashcards
(76 cards)
1
Q
prokaryote
A
- genetic info free floating around the cell
- no membrane-bound organelles
- (DNA found in plasmids)
2
Q
eukaryote
A
- genetic info found inside a membrane bound organelles
3
Q
what is found in prokaryote and eukaryote?
A
- cytoplasm
- cell membrane
- cell wall
- ribosomes (smaller in prokaryotes)
4
Q
mitosis?
A
basic cell division
- daughter cell identical to parent cell
- 1 round of cell division
5
Q
meiosis?
A
cell division for sexual reproduction
- 2 rounds of cell division
- 4 gametes produced - contains only half of the DNA compared to parent cell
- diploid and haploid cells
6
Q
what is a diploid cell?
A
daughter cells that has a full set of chromosomes
7
Q
haploid cells
A
daughter cells that has half the no. of chromosomes as the parent cell
8
Q
building block of carbohydrates
A
glucose
(can be other sugars)
9
Q
building block of proteins
A
amino acids
10
Q
building block of fats (lipids)
A
fatty acids and glycerol
11
Q
full form of DNA
A
Deoxyribo Nucleic acid
12
Q
function of ethene
A
plant hormone that causes fruits to ripen
13
Q
function of auxin
A
cell elongation due to unequal distribution in tips of shoots and roots
14
Q
four bases of DNA
A
adenine - thymine
cytosine - guanine
15
Q
genotype
A
the full set of alleles present in the cell
16
Q
phenotype
A
the characteristic
17
Q
the part of the brain that is responsible for decision making
A
cerebral cortex
18
Q
the part of the brain that is responsible for coordinating muscular activity and balance
A
cerebellum
19
Q
part of the brain responsible for unconscious activities
A
medulla oblongata
20
Q
full form of FSH, where is it produced and its function
A
- follicle stimulating hormone
- pituitary gland
- maturation of egg in the follicle and stimulates the ovaries to produce oestrogen
21
Q
oestrogen - where is it produced and its function
A
- ovaries
- inhibits further release of FSH (to prevent multiple eggs from maturing)
- stimulates thickening of the uterine lining
- stimulates LH production
22
Q
LH
- full form
- where is it produced
- function ?
A
- lutenising hormone
- pituitary gland
- ovulation - causes release of the egg from the ovary to the uterus around day 14 of the menstruation cycle. The egg travels down the fallopian tube and into the ovary where it waits to be fertilised by a sperm cell
23
Q
What is a hormone?
A
- a molecule/protein that is secreted from a gland
- travels through the bloodstream until it binds to its receptors
- and this produces an effect
24
Q
hormonal communication vs. nervous communication
A
hormonal communication lasts longer, is slower and affects many organs/tissue types
nervous communication is quicker, instantaneous and very specific in its action (only affects a few cells/tissue)
25
what is a synapse?
- gap between two neurons
- chemical called neurotransmitter is released from one neuron, which then DIFFUSES across the gap and binds to receptors on the second neuron
- triggers an impulse at the second neuron
26
cerebral cortex?
outer part of the brain - controls consciousness actions, intelligence, language , memory
27
cerebellum
back of the brain - controls muscle movement and maintains balance
28
what is the name of the membrane that surrounds the brain?
meninges
29
medulla oblongata
bottom of the brain - connects to the spinal cord
- controls unconscious actions - breathing/heart rate/digestion
30
why are reflex actions processed by the CNS and not the brain
- reflex actions completely bypass the brain
- this saves time in making decisions - we can respond faster in a dangerous / life-threatening situation faster.
31
where is insulin produced
pancreas
32
type 1 diabetes?
- insufficient insulin produced from the pancreas
- high blood glucose - glucose is passed in the urine
- early onset - genetically linked although we suspect that it is an autoimmune disease
33
type 2 diabetes?
- insulin receptors no longer respond to insulin
- late onset disease
- high blood glucose concentration and glucose is found in the urine
- causes - high fat/carbohydrates diet, lack of exercise, obesity
34
when is insulin produced
right after you have had a meal
35
what does insulin do?
1. lower blood glucose concentration by stimulating cells to absorb glucose (this is effective bc we want to take glucose out of the blood)
2. stimulates the conversion of glucose --> glycogen
36
where is glycogen stored?
skeletal muscles and the liver
37
why is a high blood glucose concentration dangerous?
- disrupts osmotic balance
- can cause high blood pressure- ruptures thin capillaries in eye etc
38
when might we be running low on glucose in the blood? what hormone is released when this happens and where is this hormone released from?
- in between meals, when are hungry, fasting
- during rigorous exercise
- glucagon is released from the pancreas
39
function of glucagon?
- binds to receptors in the liver and muscle - stimulates the breakdown of glycogen into glucose
40
can you differentiate between these key terms that all sound the same - glucose, glycogen and glucagon?
1. glucose - a single unit of sugar. it is six-membered ring and is broken down to release energy
2. glycogen - a polymer with repeating units of glucose
3. glucagon - hormone that breaks down glycogen --> glucose
41
what is an antibody
it is a Y-shaped immunoglobulin protein that binds to antigens
42
what is an antigen
- it is a protein that is found on the outer membrane of the cell
- each species has its own antigen
- acts as a biological fingerprint
- helps the body differentiate between 'self' and 'non-self' cells
43
how does an antibody work
- binds to antigens on pathogens
- makes them clump together
- alerts WBCs to come kill the pathogen
44
what are the four factors that affect transpiration
- light intensity
- temperature
- air movement
- humidity
45
transpiration vs transpiration stream ?
transpiration is the loss of water vapour through the stomata
whereas
transpiration stream is the movement of water from the roots and into the plant, up the xylem, through the leaf and out through the stomata
46
why does the human heart have valves
to prevent backflow of blood
47
oxygen debt
the extra oxygen that is needed to break down the lactic acid formed when muscles respire anaerobically
usually happens after intense exercise
48
stem cell?
an undifferentiated cell that has the potential to differentiate into any type of cell
49
differentiation
the process by which an undifferentiated stem cell becomes specialised to perform a specific function
50
where are stem cells found in animals(humans)
embryos and bone marrow
51
where are stem cells found in plants
tips of roots and shoots
52
what is the meristem
stem cells tissue in the stems of plants
53
why are stem cells so useful
can be used to cure many diseases such as cancer, blindness, organ failure but stem cell research is controversial
54
Test for sugars
Blue Benedict's solutions turns brick-red when heated
55
test for starch
yellow iodine - turns blue black in the presence of starch
56
test for lipids
add ethanol - should form cloudy white layer
57
test for proteins
blue Biuret solution turns purple/lilac in the presence of proteins
58
where is bile produced?
what is the function of bile?
1. liver
2. works in the small intestine to - a) neutralise the acidic food coming from the stomach and b) emulsifies fats in the small intestine to increase the surface area for enzymes to work on
59
what happens to food in the small intestine?
- food is broken down into its constituent molecules
- food is absorbed into the blood stream via vili (finger-like protrusions)
60
why does the stomach form an inner lining of mucus
to protect the inner stomach lining from the HCl released into the stomach. the acid is there to kill any pathogens in the food
61
what are the components of blood?
- plasma -> yellow liquid where everything is dissolved into. the plasma is the main transport medium
- red blood cells -> carries oxygen - contains haemoglobin
- white blood cells -> fights foreign cells/pathogens - engulfs pathogens, releases antibodies and antitoxins
- platelets - important in clotting blood
62
what is the flow of blood in the heart ?
vena cava -> right atrium -> right ventricle -> pulmonary artery -> LUNGS -> pulmonary vein -> left atrium -> left ventricle -> aorta -> BODY
63
arteries?
- carries blood AWAY FROM HEART
- very thick walls with elastin to withstand the high pressure from the aorta
- very small lumen
64
vein?
- carries blood TO the heart
- widest lumen
- not a lot of elastin in the walls - blood travelling at very low pressure
- has valves - to prevent backflow
65
capillaries?
- 1 cell thick walls - decreases diffusion distance - higher rate of diffusion
- walls are permeable - molecules exchanged in and out
66
what does the blood transport
- O2
- CO2
- urea from the liver to kidneys
- carbohydrates and products of digestion
67
what is diffusion
the process by which molecules moves from an area of high concentration to an area of low concentration
68
factors affecting diffusion
- surface area
- temp
- diffusion distance
- concentration gradient
69
osmosis
movement of WATER from an area of high concentration of WATER to an area of low concentration of WATER through a semi-permeable membrane
70
isotonic
conc of solutes outside the cell = conc of solutes inside the cell
71
hypotonic
conc of solutes outside the cell < conc of solutes inside the cell
72
hypertonic
the opposite of hypotonic - you better not forget this again :(
73
what is the difference between viruses and bacteria
viruses reproduces INSIDE cells
bacteria reproduces OUTSIDE cells
74
why do we have no drugs against viruses
viruses reproduces inside cells so you can't kill viruses without killing body cells as well
75
how do vaccinations work?
- Vaccinations are made of a weakened, dead or attenuated form of the pathogens
- injected into the bloodstream
- white blood cells recognise foreign antigens and creates antibodies against the antigen
- memory cells then remember the antibodies so your body remembers it if the body was to get infected with the same disease again
76
what is herd immunity?
if the majority of the population is immunised against a disease, it will protect the small portion of the population that is not immunised against the disease
