biology (y9) Flashcards
function of ribosomes
make proteins
what happens in mitochondia
respiration, releasing energy
what does the nucleus of a cell do
controls activity of cell
what does the cell membrane do
controls movement of substacnes in and out
how do meristems help a plant develop
allow plant to grow longer roots, plant grows taller and wider
what is a eukaryotic cell
a nomral cell: animal, plant, fungi etc, are normally arund 10-100 micrometers in size
what is a prokaryotic cell
a simple organism, eg: bacteria, less than 2 micrometres in size
what are the 4 phases of mitosis
prophase, metaphas, anaphase and telephase
what happens in the prophase phase
chromosomes are 2 sister chromatids and a centromere. Nucleur enevelope breaks down, centriole from that divides into 2 and moves to opposite poles, spindles start to form
what happens in the metaphase phase
chromosomes line up of equator of cell, attaches to spindle fibres
what happens in the anaphase phase
centromere joining sister chromatids splits, fibres pull chromatids to opposite poles
what happens in the telephase phase
nucleus develops around 2 ets of duplicated chromosomes, after mitosis occurs, cytokinese occurs when the cell splits into two parts
what are meristems
groups of undifferentiated cells that dibide to make all the different cells of a plant
what does phloem transport
sugars
what does xylem transport?
water and minerals
structure of phloem
elongated with pores
structure of xylem
dead and hollow tubes
where are xylem and phloem found in the leaf
in vascualr bundles- phloem near lower surface and xylem above it
where are xylem and phloem found in the stem
near edge of stem, phloem closer to edge, xylem more inside
where are xylem and phloem found in the root
centre of root, xylem in an ‘x’ with phloem tubes around it
how are lungs and gills adapted for gas exchange
large SA, fast diffusion, good blood supply, thin walls, mainatins conc. gradient
whta happens to intercostal muscles and diaphragm when we breathe in
intercostal muscles contract and move ribs up and awya, and diaphragm contracts and moves down lower to spine
what is starch tested by and what is the original colour
iodine - orangey, brown
what is protein tested by and what is the original colour
biuret solution, light blue
what is lipid tested by and what is the original colour
ethanol - clear
what is glucose tested by and what is the original colour
benedicts solution - blue
what colour would a substance turn if it had starch in it
blue black
what colour would a substance turn if it had glucose in it
tomato red
what colour would a substance turn if it had lipid in it
milky white
what colour would a substance turn if it had protein in it
pale purple
what type of food is digested in the stomach and by what enzyme
protein, by protease
what is transpiration : two answers-
the evaporation of water vapour from the stomata of a leaf, the movement of water from the leaves to the plant to the leaves
4 sections of the leaf
upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis
4 ways transpiration is affected
light- more bright light increases it, temperatue- higher temperature means quicker evaporation and diffusion, wind- water vapour is removed quickly by air movment, humidity- is slower because extra vapour in the air
what is the movement of sugars called
translocation
5 uses of glucose:
respiration, energy - storage of it, plant growth and repair and strengthening plant cell walls
what are absorbed by active transport in the roots ( from the soil)
nitrate ions
how are leaves adapated to maximise photosynthesis
large SA - more space to absorb sunlight,
chlorophyll - absorbs sunlight makes sunlight into energy and chemicals, have stomata - to allow c02 and 02 to diffuse in and out ,
network of veins - to support leaf and transport water and carbs,
wax cuticle - lets light out and protects sufrace of leaf.
word euqation for photosynthesis
water + carbon dioxide = (by light) =glucose + oxygen
symbol equation for photosynthesis
6C02 +6H20 goes to C6H1206+602
what does cell sap do?
stores chemicals and helps control water content of cell
what does a chloroplast do?
absorbs light for photosynthesis
what does a vacuole do?
maintains cell shape and stores cell sap
what does the cell wall do?
support cell and keep its shape
where are meristmes usually found?
in shoots tops and stems of plants
once stem cells are removed from a ? - ?day old embryo it can turn into any ? of cell
3-5, type
what are specialized cells?
cells that have structures - adaptations that allow them to do a particular job
eukaryotic cell vs prokaryotic cell : a EK has a nucleus, ? , normally a cell ?, has membrane bound organelles, a flagellum (?), and ribosomes , whereas a PK cell has DNA, it always has a cell? , has ribosomes, is a capsule and ? has a flagellum
DNA, wall, sometimes, wall, mostly
what 4 parts do animal cells not have that plant cells do?
cell wall, cell sap, chloroplasts and a permanent vacuole
cons of stem cells!
1. embryos don’t have to be used, can use ? cells instead
2. body can sometimes ? stem cells
3. people may have different opinions, eg : if they are religious - ?, or if they had personal experiences- like a ?
adult, reject, Christianity, miscarriage
what conditions can be cured by stem cells?
Parkinson’s, diabtetes, arthritis
stem cells are in specialized cells that can ? each other to make identical ? cells which can then make many different types of ? cells
copy, stem, specialized
cons of adult stem cells?
can’t make as many different types of specialized cells
where are stem cells found?
bone marrow, embryos, and shoot tips (meristems)
how many pairs of chromosomes in humans?
23 pairs
chromosomes are found in the nucleus, what substance us arranged into chromosomes ?
DNA
mitosis functions in multicellular organisms :
growth and repair of tissues as well as asexual reproduction
functions of mitosis in unicellular organisms:
binary fission
how is a root hair cell specialized?
has a thin cell wall, large SA, and many mitochondria for respiration
how is a red blood cell specialized?
is biconcave, has no nucleus so it can fit max amount of haemoglobin
how is a nerve cell specialized?
they are long and thin and form connections with neurones and muscle cells
how is a cone/rod specialized?
they have many mitochondria, and the outer segment is filled with visual pigment
how is a fat cell specialized?
has a (large) energy store, very little cytoplasm and can increase in size
how is a muscle cell specialized?
is elongated, can contract and has lots of mitochondria
order cell, organism, organ system, tissue and organ in order from largest to smallest :
organism —> organ system —> organ —> tissue —> cell
what happens when you breathe out?
the intercostal muscles relax, ribs move down and closer to spine, and the diaphragm relaxes and moves up and the vol of air in chest decreases
what is the definition of diffusion?
the spreading of the particles of a gas, eg : oxygen or particles im of any solution eg : glucose, resulting in a movement of particles from an area of high conc to an area of low concentration.
what factors affect and increase diffusion time?
Hugh remix large SA, higher gradient and smaller particles eg: lots of particles to a few
what state has the fastest diffusion?
gas
due to a smaller SA : ? ratio in multicellular ?, surfaces and organ systems need to be ? to exchange materials effectively
Vol, organisms, specialised
effectiveness of an exchange system is increased by 4 different factors - name them and describe how it improves diffusion :
large SA - more space for diffusion,
thin membrane (normally one cell thick) - a short diffusion path,
good blood supply - steep conc gradient,
well ventilated - also steep concentration gradient.
all of these mean a faster rate of diffusion
what is active transport?
moving up or against a concentration gradient, or when molecules/ions move against a conc gradient across a semi permeable membrane
what does active transport use energy for? (and where does the energy come from?)))
to make ‘protein pumps’ which move particles the wrong way - this energy is from aerobic respiration so could be for example glucose from intestine into blood
which route does O2 take to get to the blood? and how is the route for CO2 different?
O2 passes through trachea —> bronchus —> bronchiole —> alveoli —> blood, CO2 is different as it goes the opposite way and leaves the blood and body
what is osmosis?
when water moves from an area of high conc of water to an area of low concentration of water across a semi-permeable membrane!!! x
what is the difference between high and low conc and high and low water conc
high conc is the same as low water conc and vice versa with low conc and high water conc
what would happen to a cell that had been put in 1.0 M of sucrose? (OSMOSIS)
the cell would contain less water as the water would diffuse across the semi permeable membrane due to the high conc of water in the cell and low conc of water in the sucrose. this leads to it losing water and becoming FLACCID
what would happen to a cell that had been put in 0.0 M of sucrose? (OSMOSIS)
it would get full of water as it would absorb all the water since the water is moving from a low conc to a high conc (or high water conc to low water conc) and because of this it’ll be quite hard and turgid
potato chip experiment - need to be able to explain osmosis… what happened to the mass of the 0.0M chip and the 1.0M chip - COMPARE!!!
mass increased for 0.0M, while 1.0M stayed the same and even slightly lost mass
what is a hypotonic solution?
hypo - so lower, so low conc, so a solution with a high concentration of water and therefore a dilute solution
what is a hypertonic solution?
hyper means higher, so high conc, low water concentration, so concentrated solution!
what’s an isotonic solution?
a normal solution
what happens to red blood cells if put in a hypotonic solution?
they burst as they absorb so much water - cause low to high - water diffuses across the semi permeable membrane into the rbc s !
what happens to red blood cells if put in a hypertonic solution?
they become crenated/crinkled as there is a high conc outside and low inside so water will diffuse out across the semi permeable membrane
where are meridtems found?
tips of roots and shoots, and around vascular tissue in stems
what types of plants can easily be cloned with meristems?
plants that are resistant to diseases!
what are xylem and phloem called together?
transpiration stream
what do roots stems and leaves work together to do?
transport water, sugar and minerals around cells
leaf - a site of gas exchange and ? , and water loss by ?
stem - supports plant, transpiration ?
roots - anchor plant and absorb ? and dissolved ?
photosynthesis, transpiration, stream , waterrr, materials!
what is the acronym for uses of glucose?
RSPCA - respiration, starch, protein, cellulose and fats
what can magnesium deficiency cause?
yellow leaves
what can a nitrate deficiency cause?
poor growth, yellow leaves
what can potassium and phosphorus deficiency cause?
both - discoloured leaves
potassium - poor growth of fruit
phosphorus - poor root growth
what is the independent variable plotted on and why?
the x axis, as it is the factor you are changing
what axis is the dependent variable plotted on and why?
the y axis, as it is the one you are measuring and it is dependent on the independent variable - like a metal rod or a stand is dependent on the balancing part of the stand
parts of the upper epidermis (and characteristics)
section closest a to surface, has no chloroplasts (sun shines through to palisade mesophyll for photosynthesis) , has a waxy cuticle which stops water evaporating from leaves
palisade mesophyll?
where 80% of photosynthesis happens, near top for max photosynthesis, palisade cells are packed tightly to maximise no of cells and photosynthesis as well as chloroplasts being at the top of cells for max sunlight!!!
spongy mesophyll
where most gas exchange happens, has a large SA for co2 absorption from irregular shaped cells - (have chloroplasts so can photosynthesise), has air spaces for co2 to move to palisade later for photosynthesis, as well as stores vascular bundle of xylem and phloem (transport sugar, water and minerals as well as products of photosynthesis , eg: o2 )
lower epidermis
lots of stomata for gas exchange, bring in co2 for photosynthesis (and take out o2) , stomata are controlled by guard cells which open and close for o2 and co2 diffusion in and out
when does the stoma/stomata open?
when guard cells fill with ? by osmosis,
the thicker inner ? stretches less than the thin ?wall,
making the guard ? bend in a banana shape,
the stoma then ? between the guard cells
water, wall, outer, cell, opened
translocation - what happens?
sugars are transported from ? for immediate use for respiration, normally these are as sucrose and as ? acids, this is by the use of ? cells, and is an active process meaning it can move in ? direction but ? at the same time
leaves, amino, phloem, any, NOT
equation for intensity?
1/d squared
in a graph of rate photosynthesis plotted against temp, why is the rate so low at 5 degrees and at 80?
at 5 degrees it is just the start of the experiment and the rate is rising but the enzyme hasn’t got to its optimum temperature yet (37 degrees so room temp) , however at 80 it has gone past the optimum temperature meaning that it is too hot for rhe enzyme to function and it starts to denature it - meaning the enzyme gradually loses its use and by 80 degrees it is fully denatured and cannot function anymore
what does a potometer measure?
the rate of transpiration by uptake of water
how does a potometer work?
you measure the time and how far the air bubble has gone in that time and then work out the rate by how many cm per minute the bubble has moved
transpiration process : water from soil enters ?, via root hair ? water then moves from cell to ? till it meets the ? , where xylem and ? transport water around the rest of a plant - eg : going into a leaf and giving water to the ? in the leaf to hydrate the leaf
roots, cell, cell stem, phloem, xylem
what does a watering system do?
delivers a regular supply of water
what does hydroponics do?
it is a controlled watering system that grows roots in rock wool and mineral rich water
what does shading help control?
amount of light and temp
what is biological control?
a relatively closed growing environment that can use organisms to control pests
what does ventilation help control?
temp and humidity
humidifiers reduce what?
transpiration and need for watering since they add more moisture to the air
what does heater a do?
increases temp so more photosynthesis
what does heater b do?
increase conc of co2 if a paraffin heater is used, and high concentration of CO2 means high rate of photosynthesis
there will always be starch when you have both light and ?
CO2
what colour is a non variegated leaf?
green
where does the breakdown of starch take place?
mouth, small intestine
where is amylase made?
duodenum (small intestine), pancreas and salivary gland
where are amino acids digested?
in the stomach and small intestine
where’s fat digested? (and what is it digested into and by)
small intestine, into fatty acids and glycerol and by lipase
how does bile and lipase emulsify fat?
lipase work over the surface of the ? , then the bile emulsified the ? into tiny droplets of ? which lipase then works over the surface of each of these ? and emulsified them into fatty acids and ?
drop (of fat), drop, lipid, droplets, glycerol
how does increasing the SA Of lipids aid digestion ?
because they are easier to digest as they can be absorbed easily by villi
how are leaves adapted to maximize photosynthesis?
large SA, chlorophyll, stomata, network and veins, wax cuticle
where are sugars made?
in the companion cell!
where do sugars diffuse into phloem from?
companion cell
what happens when water enters phloem by osmosis?
movement of water in phloem makes sugars sunk to the root
what happens when sugars have sunk from the phloem to the sink cell/root
sucrose is stored as starch
what is bile?
ab alkaline liquid which neutralizes stomach acid and provides optimum pH for pancreatic enzymes
what enzymes are only made in the pancreas?
proteas and lipase
movement of water in root hair cells :
1. root hair cells have a large ? for water ?
2. water enters root hairs by ?
3. water moves across root 1 ? at a time
4. water renters xylem of ?
5. water moves up xylem in ? and then leaves xylem and enters ? cells by osmosis
6. water moves across leaf ? cell at a time
7. remaining water ? into the air spaces of spongy ?
8. this raises the humidity, so from air ? water diffuses out of ? and evaporates from surface of ?
SA, uptake/absorption,
osmosis,
cell,
stem,
stem, leaf,
1,
evaporates, mesophyll,
spaces, stomata, leaf
what is fat used for?
to make cell membranes and cholesterol and vitamins
