B1.1 Cell Structures

Question 1

Eukaryotic cell

Answer 1

Cells whose genetic material is contained within a nucleus

Question 2

Prokaryotic cell

Answer 2

Cells whose genetic material floats within the cytoplasms

Question 3

Name the organelles ALL eukaryotic cells contain.

Answer 3

Nucleus

Cell membrane

Mitochndria

Cytosplasm

Question 4

Name the EXTRA subcellular structures found in plants to animal cells.

Answer 4

Chloroplast

Cell Wall

Vacuole

Question 5

Function of the nucleus

Answer 5

• Controlling the activities in the cell
• Contains the organisms genetic material, arranged as chromosomes
• Determines cells appearance and function

Question 6

• The ‘power-house’ of the cell.
• Provides energy by respiration

Answer 6

Mitochondria

Question 7

Function of the cell membrane

Answer 7

• Delicate surface membrane made of two layers of phospholipid
• Holds the cell together
• Controls what goes in and out of the cell

Question 8

• Transfers energy, makes things, and stores food.
• Jelly-like substance where hundreds of reactions take place, which make up metabolism.

Answer 8

The cytoplasm

Question 9

This cell type is complex and relatively large 10-100 μm

Answer 9

Eukaryotic e.g. plant & animal cells

Question 10

Which English inventor and scientist where discovered cells using his self-designed microscope in 1665?

Answer 10

Robert Hooke

Question 11

MRS GREN

Answer 11

M = ovement

R = espiration

S = ensitivity

G = rowth

R = eproduction

E = xcretion

N = utrition

Question 12

This cell type is simple and typically smaller ~1-10 μm

Answer 12

Prokaryotic cells e.g bacteria cells

Question 13

What are ribosomes and what is their function?

Answer 13

Ribosomes are tiny granules on the membranes in the cytoplasm.

Ribosomes are where proteins are made in the cell.

Question 14

This organelle harnesses energy from the sun for photosynthesis

Answer 14

Chloroplast

Question 15

What is a a vacuole and what is its function?

Answer 15

• Vacuole a large cavity filled with a watery fluid called cell sap.
• It helps keep the cell rigid, pushing outwards.

Question 16

• This structure surrounds the cell.
• It is made of cellulose, a tough rubbery fibre.
• It gives the cell rigidity and supports the cell.

Answer 16

Cell wall

Question 17

Name of primative bacteria-like organisms

Answer 17

Archaea

Question 18

What is a plasmid and how can it be advantageous?

Answer 18

• A circular piece of DNA found in bacteria cells
• Not needed for day-to-day survival but can give the bacterium advantages such as antibiotic resistance

Question 19

Tiny ‘hair-like’ structures that allow the cell to attach to structures, such a the cells in your digestive tract. They are also used to transfer genetic material between bacteria cells.

Answer 19

Pili

Question 20

What is the function of a slime capsule?

Answer 20

• Protects bacteria from drying out and from poisonous substances.
• Helps bacteria to stick to smooth surfaces

Question 21

List the structures and organelles you would expect to find in a bacteria cell.

Answer 21

• Cell wall (peptigoglycan)
• Cell membrane
• Flagella
• Single-loop DNA
• Plasmids
• Pili
• Cytoplasm
• Slime capsule

Question 22

State three examples of commonly found bacteria

Answer 22

• Escherichia coli – Causes food poisoning
• Streptococcus – bacteria causes sore throats
• Streptomyces – bacteria found in soil and used to develop antibiotic streptomycin

Question 23

Tail-like structures that allow bacteria cells to move through liquids

Answer 23

Flagellum

Question 24

Name the parts of a light microscope

Answer 24

• Body tube
• Fine focussing knob
• Mechanical stage
• Stage
• Objectives
• Course focussing knob
• Revolving nosepiece
• Lens
• Mirror
• Arm
• Base

Question 25

What is the equation for magnification?

Answer 25

Image size = Actual size x Total Magnification

Question 26

Resolution

Answer 26

• The degree to which it is possible to distinguish between two objects that are very close together, rather than them look merged into one object.
• The higher the resolution, the greater the detail you may see

Question 27

Name the two types of electron microscope

Answer 27

• Transmission electron microscope (TEM)
• Scanning electron microscope (SEM)

Question 28

What are TEM used for and how have they advanced science?

Answer 28

• TEM is used to examine an extremely thin slice or section of cells or tissues
• TEM has revealed subcellular structures in cells not visible with a light microscope such as mitochondria and chloroplasts

Question 29

What are SEM used for and how have they advanced science?

Answer 29

• SEM has a large depth of field so can be used to examine the surface structure of specimens.
• They produce a 3-D image of a surface by bouncing a beam of electrons off of a specimen.

Question 30

What are the advantages and disadvantages of light microscope and electron microscopes?

Answer 30

Light microscope

• Cheep to buy and operate
• Small and portable
• Simple to prepare sample
• Natural colour of sample is seen unless staining is used.
• Specimens living or dead
• Resolution up to 0.2 µm
• (2 x 10-7 m)

Electron Microscope

• Expensive to buy and operate
• Large and difficult to move
• Sample preparation is complex
• Black and white images produced; false colour can be added to images
• Specimens are dead
• Resolution up to 0.1 nm
• (1 x 10-10 m)