B1 Cell structure and transport

Question 1

How do Light Microscopes work?

Answer 1

Beam a light around an object

Question 2

How far can they magnify

Answer 2

around 2000x

Question 3

Benefits of a light microscope

Answer 3

cheap,can be used anywhere and can magnify live specimens

Question 4

How do electron microscopes work

Answer 4

They use a beam of electrons to form an image

Question 5

How far can they magnify

Answer 5

2 000 000x

Question 6

Difference between transition and scanning electron microscopes.

Answer 6

Transition takes 2d images at high resolution and high magnification
Scanning take 3d images but at lower magnification

Question 7

Disadvantages of electron microscope

Answer 7

Large,very expensive, have to be kept in special temperature pressure and humidity

Question 8

Magnification of a light microscope

Answer 8

Eyepiece lens magnification x Objective lens magnification

Question 9

The formula to calculate the size of an object

Answer 9

size of real object= size of image/magnification

Question 10

What is resolution

Answer 10

the shortest distance between two points on a specimen that can still be seen as two different points by the observer

Question 11

Resolving power of Light and electron microscope

Answer 11

Light microscope- 200nm
A scanning electron -10 nm
a transition - 0.2nm

Question 12

What do the nucleus of an animal cell do

Answer 12

controls all the activities of the cell and contains the genes for chromosomes that carry the instruction for making the proteins needed to build new cells.In a diagram it is repecented by the biggest circle within the cell

Question 13

What does the cytoplasm do in an animal cell

Answer 13

the gel in the cell where most chemical reactions happen. In a diagram it is represented as the interior backround inside the cell.

Question 14

What is the cell membrane do in a animal cell

Answer 14

Controls the passage of substances such as glucose and mineral ions into the cells and substances like hormones out of the cell.In a diagram it is represented as the wall outside of the cell.

Question 15

What does the mitochondria do in a animal cell

Answer 15

Aerobic respiration takes place in here releasing energy for the cell.They are either represented as small dots or ovals in the diagram

Question 16

What do ribosomes

Answer 16

protein synthesis happens here making all the proteins needed for the cell.Either represented as small dots near the stringy material which is the endoplasmic reticulum in the cell diagram.

Question 17

How are plants different from animals.

Answer 17

They do not move and they make food from themselves in a process called photosynthesis

Question 18

What is the cell wall in the plant cell

Answer 18

They are made of cellulose that streghthens the cell and gives it support. Represented as the thick wall outside the cell membrane.

Question 19

What do chloroplasts do in a plant cell

Answer 19

They contain the green substances chlorophyll which makes the green and absorbs light so the plant make energy via photosynthesis.They are found on cells above ground because the light is not found undergriund.They look like green mitochondria

Question 20

What does the permament vacuole do in a plant cell

Answer 20

It is a space in the cytoplasm filled with cell sap and this is important for keeping the cells rigid to support the plants

Question 21

What are plants and animals both examples of and what does this mean

Answer 21

Animal and plant are both eukaryotes along with fungi and protists which means they all have nucleus that produces the genetic code (DNA)

Question 22

Bacteria are

Answer 22

single celled organism and an example of prokaryotes along with archaea

Question 23

How small do bacteria get

Answer 23

0.2 to 2.0 micrometres

Question 24

What do Prokaryotic cell contain sometimes

Answer 24

Extra small rings of DNA called Plasmids which code for specific features

Question 25

What do they have instead of a nucleus

Answer 25

Genetic material in a loop

Question 26

What are the two specific features that some bacterial cells have

Answer 26

A slime capsule that is protective and a flagella which moves them around

Question 27

What do cells do as a organism develops

Answer 27

differentiate to form different types of specialised cells

Question 28

What are Nerve cells specialised to do

Answer 28

Carry electrical impulses to provide a rapid communication system between different parts of the body

Question 29

What are the nerve cells adaptations

Answer 29

lots of dendrites to make connections with other cells
a long axon to carry the nerve impulse from one place to another
the synapses are adapted to pass the impulses to another cell or a muscle using special transmitter chemicals and they have lots of mitochondria to help make the chemicals

Question 30

Muscle cells are specialised in what way

Answer 30

They can contract and relax

Question 31

What do striated muscles cells do

Answer 31

move different parts of the body

Question 32

Adaptations of Striated muscle cells

Answer 32

-They contain special proteins that slide making the fibres contract
-Contain many mitochondria to transfer the energy needed for the chemical reactions that take place as the cells contract
-Stores glycogen which can be used by the mitochondria as energy

Question 33

Adaptations of sperm cells

Answer 33

-Tails to move to the egg
-The middlesection has mitochondria to provide energy to the tail
-The achrosome has enzymes to break the egg
-the nucleus has the genetic information

Question 34

What are root hair cells

Answer 34

Cells in the root that takes in water and mineral ions and is close to the xylem so the rest of the plants can have these so photosynthesis can occur

Question 35

adaptations of root hair cells

Answer 35

bigger surface area to take in more water
large vacuole that speeds up water to speed up the movement of water by osmosis
many mitochondria to provide energy for the active tansport of minerals ions

Question 36

photosynthetic cells adaptations

Answer 36

Have chloroplasts to trap light for photosynthesis
-Positioned in continuous layers in the leabes and outer layers so they absorb as much light as possible
-They have a large permament vacuole that helps the cell rigid and helps the leaf spread out so iit can capture as much light as possible

Question 37

What is the xylem cell

Answer 37

the xylem is the transport tissue in plants that carries water and minera;s opms from the roots to the rest of the plant

Question 38

adaptations of the xylem cell

Answer 38

cells are alive but dies and form long hollow tubes that allow water and mineral ions
to easily move through them
-spirals of lignin in the xylem cells make them very strong.

Question 39

adaptations of phloem cells

Answer 39

phloem is specialised transport tissue that carries the food made by photosynthesis around the body of the plant
-the cell wall betweens the cells break down to form special sieve plates these allow water carrying the food to move freely op and down the tubes to where it is needed
-phloem cells lose a lot of their internal structures but they are supoorted by companion cells that keep them alive.

Question 40

What is one way substances like glucose and oxygen move in and out of the cell

Answer 40

diffusion-moving from area of high concentration to a lower concentration, it takes place because the random movement of particles bump around until they are in a random concentration