chapter 2: basic components of living systems

Question 1

explain dry mount sample preparation for microscopy

Answer 1

solid specimen cut to thin slice.
place on slide and place cover slip over it

Question 2

explain wet mount sample preparation for microscopy

Answer 2

specimen suspended in liquid
place on slide and place cover slip on at an angle

Question 3

explain squash slide sample preparation for microscopy

Answer 3

wet mount is prepared, then a lens tissue is used to gently press down the cover slip

Question 4

explain smear slides sample preparation for microscopy

Answer 4

sample placed on slide. edge of a different slide is then used to smear the sample across the slide, creating a thin even layer.
cover slip is then placed over the sample

Question 5

what is gram staining technique used for

Answer 5

to separate bacteria into 2 groups. gram positive and gram negative.

Question 6

process of gram staining technique

Answer 6

slide prepared with bacteria specimen on it.
crystal violet is applied, the iodine is applied, which fixes the dye.
slide is then washed with alcohol
gram positive bacteria will appear purple under a microscope
gram negative will lose the purple stain.
they are then stained with a counterstain, which will make them appear red

Question 7

define resolution

Answer 7

the ability to see individual objects as separate

Question 8

define magnification

Answer 8

how many times larger the image is than the actual size of the object

Question 9

magnification equation

Answer 9

I = AM

Question 10

1 graticule division = ?

Answer 10

number of micrometres / number of graticule divisions

Question 11

how does a graticule work measure specimens?

Answer 11

look at graticule scale
count how many graticule divisions long the specimen is
use scale to find out magnification factor
actual length of specimen = graticule units X magnification factor

Question 12

2 types of electron microscopes

Answer 12

transmission electron microscope (TEM)
scanning electron microscope (SEM)

Question 13

explain how TEM works

Answer 13

beam of electrons is transmitted through specimen and focused to produce an image

Question 14

Explain how SEM works

Answer 14

beam of electrons is sent across the surface of the specimen and the reflected electrons are collected.
3D images are produced

Question 15

Explain what is produced when using a laser scanning microscope

Answer 15

high resolution image
is non invasive
2d images are produced but can make 3d using the 2d ones

Question 16

what part of the mitochondria is the cristae and which is the matrix

Answer 16

cristae is the lines
matrix is the space

Question 17

what’s a vesicle

Answer 17

sacs that help with transport

Question 18

whats a lysosome

Answer 18

specialised form of vesicle that are responsible for the breakdown of waste material in cells

Question 19

whats the cytoskeleton

Answer 19

network of fibres throughout the cytoplasm that maintain stability of cells

Question 20

3 parts of the cytoskeleton

Answer 20

microfilaments - responsible for cell movement and cell contraction during cytokinesis
microtubules - responsible for forming scaffolding like structure that determines shape of the cell
intermediate fibres - give mechanical strength to cell

Question 21

role of the smooth endoplasmic reticulum

Answer 21

lipid and carbohydrate synthesis

Question 22

role of the rough endoplasmic reticulum

Answer 22

synthesis and transport of proteins

Question 23

role of the golgi apparatus

Answer 23

modifying and packaging proteins

Question 24

explain protein production from the nucleus to out of the cell (5)

Answer 24

1. nucleus manufactures mRNA
2. mRNA leaves nucleus through nuclear pore
3. The rough ER has ribosomes which synthesise proteins
4. travel in vesicle to the Golgi apparatus to be modified
5. travel in vesicle to cell surface membrane where they leave the cell through exocytosis

Question 25

whats an extremophile

Answer 25

a microorganism that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.