Key concepts of Biology

Question 1

What are Eukaryotic cells?

Answer 1

complex cells such as animal and plant

Question 2

Prokaryotic Cells

Answer 2

small and simple such as bacteria cells

Question 3

what does an animal cell contain?

Answer 3

nucleus 
cytoplasm 
cell membrane 
mitochondria 
ribosomes

Question 4

Nucleus function

Answer 4

controls the activities of the cell

Question 5

cytoplasm function

Answer 5

chemical reactions take place here due to enzymes

Question 6

cell membrane function

Answer 6

controls what goes in and out

holds the cell together

Question 7

mitochondria function

Answer 7

respiration reactions take place here

Question 8

ribosomes function

Answer 8

protein synthesis

Question 9

what does a plant cell contain?

Answer 9

nucleus 
cytoplasm 
cell membrane 
mitochondria 
ribosomes 
cell wall
large vacuole 
chloroplasts

Question 10

Cell wall function

Answer 10

supports cell and strengthens it

Question 11

vacuole function

Answer 11

contains cell sap

maintains the internal pressure to support cell

Question 12

chloroplasts function

Answer 12

photosynthesis occurs

contain chlorophyll

Question 13

what does a bacteria cell contain?

Answer 13

chromosomal DNA 
ribosomes
cell membrane 
plasmid DNA 
flagellum

Question 14

Chromosomal DNA function

Answer 14

controls cells activities and replication

located in cytoplasm

Question 15

Plasmid DNA function

Answer 15

extra DNA which contain genes for drug resistance

Question 16

flagellum function

Answer 16

rotates to make the bacteria move

Question 17

what are specialised cells?

Answer 17

cells that have a structure which makes them adapted to their function

Question 18

what is the function of an egg cell?

Answer 18

to carry female DMA and to nourish the developing embryo

Question 19

how is an egg adapted to its function?

Answer 19

• nutrients in cytoplasm to feed embryo
• haploid nucleus
• changes structure so no more fertilisation

Question 20

how is a sperm cell adapted to its functions?

Answer 20

• long tail so can swim to egg
• mitochondria to provide energy
• acromsome to store enzymes to get through membrane of egg
• haploid nucleus

Question 21

what are ciliated epithelial cells specialised for?

Answer 21

moving materials such a mucus

Question 22

what is resolution?

Answer 22

how well a microscope distinguished between two points that are close together

Question 23

what does a higher resolution mean?

Answer 23

the image will be seen more clearly and in more detail

Question 24

advantages of light microscopes

Answer 24

study living things

Question 25

advantages of electron microscopes

Answer 25

higher magnification and resolution | see smaller things in detail

Question 26

Equipment needed to view a specimen

Answer 26

``` clean slide pipette tweezers cover slip mounted needle ```

Question 27

Step one of practical

Answer 27

take a clean slide and place one drop of water using pipette in middle and place specimen onto slide with tweezers

Question 28

step two

Answer 28

add a drop of stain so it is easier to see

Question 29

step three

Answer 29

place a cover slip at one end of the specimen holding it at an angle with a mounted needle and lower onto slide and clip onto stage making sure there are no air bubble

Question 30

step five

Answer 30

select lowest powered objective lens

Question 31

step six

Answer 31

adjust the focus with fine adjustment knob and measure diameter with ruler

Question 32

what is magnification?

Answer 32

how many times bigger the image is

Question 33

total magnification equation

Answer 33

eyepiece lens magnification * objective lens magnifications

Question 34

magnification equation

Answer 34

image size / real size

Question 35

what are enzymes?

Answer 35

biological catalysts that speed up the rate of reactions without being changed or used up

Question 36

what is a substrate?

Answer 36

the molecules changed in the reaction

Question 37

what is the lock and key theory?

Answer 37

an enzymes active site fits perfectly with the substrate to catalyse a reaction

Question 38

how does temperature effect the reaction?

Answer 38

higher temp speed is the reaction until it gets too hot and the bonds are broken which changes the shape of the active site and then enzymes denature

Question 39

how does ph effect the reaction?

Answer 39

enzymes have an optimum ph so if the ph is too low or high then the bonds will break and the enzyme denatures as the active site changes shape

Question 40

how does concentration effect the reaction?

Answer 40

the higher the concentration the faster the reaction as it is more likely to meet with substrate, this happens until a certain point as it has all been used up

Question 41

what does amylase break down?

Answer 41

starch to maltose

Question 42

how to detect starch and what colour it will go to

Answer 42

iodine solution | browny orange to blue black

Question 43

what is rate ?

Answer 43

measure of how much something has changed over time

Question 44

rate of reaction formula

Answer 44

1000 / time

Question 45

calculate the rate of reaction

Answer 45

amount that it has changed / time taken

Question 46

what do digestive enzymes do?

Answer 46

break down food molecules so they can pass through walls of digestive system to be absorbed into bloodstream

Question 47

carbohydrases

Answer 47

converts carbohydrates into simple sugars

Question 48

proteases

Answer 48

converts proteins into amino acids

Question 49

lipases

Answer 49

converts lipids into glycerol and fatty acids

Question 50

what is glycogen synthase?

Answer 50

joins together chains of glucose molecules to make glycogen

Question 51

how are proteins made?

Answer 51

joining of amino acids

Question 52

how are carbohydrates made?

Answer 52

joining together simple sugars

Question 53

what is diffusion?

Answer 53

movement of particles from a high concentration to a low concentration

Question 54

what substance does diffusion happen in?

Answer 54

liquids and gases

Question 55

why does it happen in these substances?

Answer 55

the particles are free to move about randomly

Question 56

what is osmosis?

Answer 56

movement of water particles across a semi permeable membrane from a high water concentration to a low water concentration

Question 57

what is a partially permeable membrane?

Answer 57

a membrane with very small holes in so only tiny molecules can pass through such as water

Question 58

why does water pass through both ways?

Answer 58

because water particles move about freely

Question 59

what is active transport?

Answer 59

movement of particles across a membrane from an area of low concentration to high concentration using energy

Question 60

how to calculate percentage change

Answer 60

final mass - initial mass / initial mass * 100

Question 61

if your results are positive what does it mean?

Answer 61

the potato chip gained mass

Question 62

Investigation osmosis experiment

Answer 62

cut potatoes all of same size measure the mass of each potato place in different concentrations of sucrose solutions and leave for 40 mins remove and pat dry to get an accurate measurement of their final masses weigh again

Question 63

what do you change in the experiment?

Answer 63

the sucrose solution concentration

Question 64

what is the control variable?

Answer 64

something that remains unchanged

Question 65

what is the independent variable?

Answer 65

what is being changed or controlled

Question 66

what is the dependant variable?

Answer 66

something that your are measuring