Cells

Question 1

What is the definition of eukaryotic cell?

Answer 1

A cell with dna in the nucleus and membrane bound organelles, bigger than prokaryotic cells

Question 2

What is an example of a membrane bound organelle?

Answer 2

Mitochondria

Question 3

How are prokaryotic cells different from eukaryotic cells?

Answer 3

They are smaller and have no nucleus, rather the dna is floating about in the cytoplasm. Some dna are in plasmids

Question 4

What is the function of nuclei?

Answer 4

Stores genetic information and controls the activities of the cell

Question 5

What is the function of cytoplasm?

Answer 5

Where the chemical reactions take place

Question 6

What is the function of ribosomes?

Answer 6

Site of protein synthesis

Question 7

What is the function of the vacuole?

Answer 7

Helps the cell keep its shape and stores water

Question 8

What is the function of the cell wall?

Answer 8

Protects the cell. Very rigid and sturdy, and made of cellulose

Question 9

What is the function of the chloroplasts?

Answer 9

Contains chlorophyll and is a site of photosynthesis which produces energy from sunlight, chloroplasts make the plant green

Question 10

What is the function of pili?

Answer 10

For sticking to surfaces and other cells

Question 11

What is the function of plasmids?

Answer 11

Extra lots of circular dna, can be for antibiotic resistance. Some produce toxins

Question 12

What type of organelles do animal cells have? (5)

Answer 12

Nuclei, mitochondria, ribosomes, cell membrane, cytoplasm,

Question 13

What type of organelles do plant cells have? (8)

Answer 13

Nuclei, mitochondria, ribosomes, cell membrane, cytoplasm, Chloroplasts, vacuole, cell wall

Question 14

What type of organelles do prokaryotes have? (6)

Answer 14

Cell wall, plasmids, pili, cytoplasm, capsules, flagella

Question 15

What is the function of flagella?

Answer 15

Movement

Question 16

What is the cell wall (membrane?) in prokaryotes made out of?

Answer 16

peptidoglycan

Question 17

Pre-1970, how were living things classified?

Answer 17

Into five kingdoms, based on observable traits

Question 18

Post-1970, how were living things classified?

Answer 18

Into three domains

Question 19

What are archaea?

Answer 19

Small, single called organisms that live in extreme environents (extremophiles)

Question 20

Why were archaea and bacteria separated into two separate domains?

Answer 20

woesse decided that if these organisms (archaea) lived in extreme environments, they must be different

Question 21

What are the differences between archaea and bacteria?

Answer 21

• dna sequencing shows their DNA is very different
• archaea ribosomes have nucleic acids more like eukaryotes

Question 22

What kind of places can archaea live in?

Answer 22

Salt planes, very hot water, deep water, etc

Question 23

What are the parts of a microscope? (4)

Answer 23

Eyepiece lens, objective lens, fine and coarse focusing knobs

Question 24

What is the eyepiece lens for?

Answer 24

The first stage of magnification, where you look into the microscope

Question 25

What is the objective lens for?

Answer 25

second stage of magnification,changes how closely magnified the image is.

Question 26

What is the fine + coarse focusing knobs for?

Answer 26

Fine-tuning the image; viewing the details and rough focusing respectively

Question 27

What is the definition of magnification?

Answer 27

The ability of a lens or other optical instrument to magnify (enlarge) the size of something in the optical

Question 28

What is the definition of resolution?

Answer 28

The ability of a microscope to distinguish between two adjacent points as seperate

Question 29

What is the definition of maximum resolution?

Answer 29

The smallest distance between two points, at which they can be recognised as separate entities. The better the resolution, the easier you can view & identify finer details

Question 30

Who was Ernst Ruska?

Answer 30

A German physicist who won the 1986 Nobel | physics prize for his work on electron optics, including the invention of the electron microscope.

Question 31

Who was Anton von Leeuwenhoek ?

Answer 31

A Dutch businessman and scientist, and the first person to see bacteria after looking closely at water with a microscope. Some of his other discoveries include blood and sperm cells

Question 32

Who was Robert Hooke ?

Answer 32

The first person to see a microorganism with a microscope. He named cells and wrote a book (micrographia) about his findings.

Question 33

Who invented the electron microscope?

Answer 33

Ernst Ruska

Question 34

How can you calculate total magnification in a microscope? (And which variables are fixed and which can change?)

Answer 34

Magnification of eyepiece lens* x magnification of objective lens** * fixed * *can change between x4 x10 x40 x10p

Question 35

What are the disadvantages of electron microscopes?

Answer 35

Can only see in black and white, very expensieve, very big, not portable, can either be SEM or TEM, thing you’re looking at must be dead

Question 36

What are the disadvantages of light microscopes?

Answer 36

Less magnification and resolution

Question 37

What are the advantages of light microscopes?

Answer 37

``` Portable see in colour specimen can be alive cheaper can be used by anyone smaller ```

Question 38

What are the advantages of electron microscopes?

Answer 38

Greater magnification and resolution can see inside cell no complex lighting

Question 39

What are the two types of electron microscope?

Answer 39

Scanning electron microscopes (SEM) and transmission electron microscopes (TEM)

Question 40

What are movement, respiration, growth, reproduction, excretion and nutrition?

Answer 40

Life processes

Question 41

What do cells group together into?

Answer 41

Tissues

Question 42

How many times can an electron microscope magnify up to compared with a light microscope

Answer 42

2 million times (electron) | 2,000 times (light)

Question 43

How does the electron microscope work?

Answer 43

Uses electron beams instead of light beams, and the electrons bounce off surface of a specimen that has a very thin coating of a gold-like metal

Question 44

What does a scanning electron microscope do?

Answer 44

The electrons scan a sample’s surface

Question 45

What does a transmission electron microscope do?

Answer 45

The electrons penetrate a sample’s surface to see inside

Question 46

“Explain how electron microscopes have increased out knowledge of sub cellular structures.”

Answer 46

“An electron microscope has a much higher magnification and resolving power, meaning it can be used to study cells in more detail. Scientists can now see and understand sub cellular structure.”

Question 47

What is resolving power?

Answer 47

The ability of a microscope to distinguish between two adjacent points (resolution)

Question 48

What is the smallest thing we can see? (With the naked eye?)

Answer 48

0.04mm

Question 49

How do you calculate magnification of an image?

Answer 49

Image size / actual size

Question 50

How do you calculate image size?

Answer 50

Magnification x actual size

Question 51

How do you convert out of standard form? (Example of 1.26 x 10^5)

Answer 51

The power of ten is how many times you move the decimal place to the /right/. If the power is negative, move to the /left/ instead.

Question 52

Why might mitochondria look different in different slides?

Answer 52

There might be mutations, different slices, natural differences or damages.

Question 53

What are stem cells?

Answer 53

Stem cells are unspecialised cells with the ability to duplicate / or duplicate and specialise

Question 54

What type of cells can embryonic stem cells differentiate into?

Answer 54

Any type

Question 55

What type of cells can umbilical cord stem cells differentiate into?

Answer 55

Blood

Question 56

What type of cells can normal stem cells differentiate into?

Answer 56

The type of cell from the tissue they are found in

Question 57

Where are embryonic stem cells found?

Answer 57

In the blastocyst, 3-5 days after fertilisation

Question 58

What is an immunosuppressant?

Answer 58

A drug that supremes an immune system so it doesn’t reject foreign tissue such as a transplanted heart

Question 59

Where are stem cells found in plants?

Answer 59

The meristem- the roots and shoots

Question 60

What diseases are stem cells being used to cure?

Answer 60

Parkinson’s and diabetes, specifically type 1 | Also age related sight loss and paralysis

Question 61

What are therapeutic stem cells?

Answer 61

“Fake” stem cells that are grown from a half a nucleus of a patient and a donated egg cell (or vice versa, if the patient is female) This means that the patient doesn’t have to take immunosuppressants

Question 62

Why can plant stem cells be useful?

Answer 62

Creating plants immune to disease, protecting endangered species, indentical plants for research,

Question 63

What is binary fission?

Answer 63

A type of asexual reproduction found in bacteria, where one organism splits to become two