science Flashcards
can we see cells with our naked eye
no
what helps us to see and draw cells
microscope
what is a cell membrane
controls what enters and leaves the cell
what is a nueclus
it stores information [dna] and control what happens in the cell33
what is a mitochondria
realeses enrrgy from food[glucose] by aerobic respiration
what is a cell wall
made from cellulose and keeps the cell rigid
what is a vacoule
contains cell sap and keeps the cell firm
what is a chloroplast
it contains green chlorophll that absorbs light energy to allow plants to make their own food
what is diffusion
this is the movement of particles from high to low concentration
what are unicellular organism
this are organism that have one cell
Name one stucture that is found in the plant cells but not in animal cells
cell wall, vacoule and chloroplast
types of unicelluar organisms
ameoba and euglena
where in a cell is energy realesed from food
mitocrondia
put these words in order of complexity starting with cell ; organism, organ, system and tissue
cell tissue organ sytem organisim
Male produces_________ cells in the __________
sperm and testes
female produces__________ cells in the _________
egg and ovary
what is fertilization?
this is when male and female cells join
what is menstruation*
this is when females have a menstrual cycle that lasts up to 28 days
what is gestation
this is the process of the embryo developing in the womb
name to types of polinated plants
wind pollinated and insect pollinated
what is pollination
the transfer of pollen by insect or wind from the anther of a flower to the stigma of another.
name two .improtance of plants
to provide us with food
which day of the menstural cycle is a female egg realesed
around the 14 days
list two ways that seeeds and friut can be dispered
wind and insect
what does breathing involve
moving air in an out of the lungs
first thing when breathing in
Ribs move up and out
second thing when breathing in
diaphragm flattens and moves down
third thing when breathing in
space inside the lung increases
fourth thing when breathing in
this increases the volume and reduces the pressure *
first thing when breathing out
ribs move down and in
second thing when breathing out
diaphragm moves up
third thing when breathing out
space inside the lung decreases
fourth thing when breathing out
decreses the volume an increases the pressure
what are the lungs made of
tiny air sacs called aveoli
name two characteristics of air sacs
tiny and moist
when does gas exgange happen
carbon dioxide is pushed out and oxygen is brought in.
how does exercise affect breathing
improves gas exgange
how does athma affect breathing*
it causes breathing tubes to narrow, making breathing diffcult
how does smoking affect breathing
damages the breathing tubes so that mucus builds up
name the process by which oxygen moves from the air in our lungs into the blood.
distillation
what is a healthy diet
a healthy diet contains all of the classes of food in the right proportion.
purpose of carbohydrate
gives the body energy
purpose of fat
provides energy supply and insulation
purpose of protein
used for growth.
purpose of vitamins
needed to keep our bodies healthy
purpose of minerals
needed to keep our bodies healthy
purpose of fibre
helps undigested food pass quickly through the gut
purpose of water
dissolves chemicals so that chemical reactions can take place
how is energy in food measured?
joules
1 calorie =to _________ joules
4.2
what causes obesity
eating to much food
when you eat to little it leads to
starvation malnutrition
not eating enough protien leads to
kwashoirkor
not eating enough vitamins
causes different diseases e.g., scurvy.
not eating enogh minerals leads to
lack of iron anaemia lack of calcium soft bones
the way food travels through
mouth esophagus stomach intestine rectum and anus
what are emzymes
these are protiens which speed up chemical reaction
what is photosynthesis
this is a process which plants make their own food
the word equation for how plants make food
water + carbon dioxide —— glucose oxygen
diffrence in feeding between plant and animals
animals eat food plants make food
what is respiration
this is the process by which organisms realese enegry
name the types of respiration
aerobic and anaerobic respiration
what is aerobic respiration
this is the process in which food (glucose) is converted into energy in the presence of oxygen
word equation for aerobic respiration
glucose + oxygen —> carbon dioxide+ energy
what is anaerobic respiration
this is when not enough oxygen is not enough
what do humans breack glucose to
lactic acid
word equation for anaerobic respiration
glucose —> lactic acid+ energy
what is fermination
this is when yeast breaks glucose down into alcohol and carbon dioxide
word equation for yeast5
glucose—–> alcohol + carbon dioxide + energy
uses glucose
both
uses oxygen
aerobic
produces carbon dioxide
aerobic and anaerobic in fermination
produces water
aerobic
releases lots of energy
aerobic
can prodce lactic acid
anaerobic in humans
can produce alcohol.
anaerobic in fermintation
causes mucscle fatique
anaerobic
name 2 functions perfromed by the skeleton
supports the body and gives it a shape. Acts like a framework
bones in the skeleton are joined togther by——–
joints
the bones in a joint are held together by_________
ligaments
the end of each bone is covered by a__________
cartilage
muscles are attached to the bones by ___________
tendons
what is an antagonistic pair?
this means each joint needs two muscles to make it work.
how is the force exerted in muscles measured in?
newtons
what is photosynthesis?
this is the process in which plants make food.
what is released as a waste product in plants?
oxygen
what is the chemical inside chloroplast that is used to perform photosynthesis?
chlorophyll
the word equation for
water + carbon dioxide —— glucose oxygen
why are leaves the place where photosynthesis takes place?
they are thin.
they have a large surface area.
they have small holes called stomata.
they have tiny tubes called xylem to carry water and minerals from the root to the leaves.
they have tiny tubes called phloem to carry glucose away for storage.
define how three of the points you have made adapt to the plant.
are thin- they are not heavy.
stomata-allow gases such as carbon dioxide and oxygen to enter or leave the leaf.
have a large surface area- to catch as much sunlight as possible.
plant and animal are ———–
interdependent
state how photosynthensis is different from respiration?
Respiration uses food and oxygen produces carbon dioxide.
what is variation?
this is when most living organisms are different from one another.
what are niches?
these are different parts of the ecosystem.
producers are ——–
plants
consumers are ————
animals
what are food webs made from?
different food chains.
what is interdependency.
this describes how living organisms in an environment depend on one another.
what do food webs show?
how organisms depend upon one another for food.
what do plants at the bottom of the food web absorb?
poison.
what do animals that eat a lot of plant absorb more?
poison
when the poison accumulates as it is passed up the food web it is called?
bioaccumlation
what do arrows on a food web show?
this is how energy transferred as food form one organism to another.
we inherit half of our genetic information from our ———- and half from our. ———-.
this is called ———–
mother and father heredity.
where is genetic information stored?
in the chromosomes.
where are the chromosomes found?
in the nucleus.
the nucleus of every cell contains ——— chromosomes
46
each chromosome consists of a ——
very long stand of dna
DNA is divided up to single units called. ———
genes
who and who developed the theory of DNA and in what year?
James Waston and Francis Crick in the year 1953
who found evidence to support Waston and crick’s theory?
Maurice Walkins
who made X-ray images of DNA and found out that DNA was a double helix?
Rosalind Franklin
which one is larger a chromosome or a gene?
a chromosome
