Cell biology 1.1-1.3

Question 1

Functions of life

Answer 1

Metabolism
Reproduction
Homeostasis
Response
Excretion
Nutrition
Growth

Question 2

Cell theory

Answer 2

All living organisms are composed of cells
Cells are the smallest units of life
Cells come from pre-existing cells

Question 3

Cells are the fundamental units of life. Explain what this means

Answer 3

All living organisms are composed of cells and that without cells, there would be no life.

Question 4

Why do multicellular organisms have emergent properties?

Answer 4

Because emergent properties arise when different cellular components interact with each other to carry out a specific functions

Question 5

Are vacuoles larger in animals or plants, why?

Answer 5

Plants.

Animal cells do not require vacuoles for rigity & pressure.

Question 6

What supports that cells arise from pre-existing cells?

Answer 6

Louis-Pasteur swan neck experiment.

Question 7

What does a larger SA:Vol ratio mean?

Answer 7

Cells can work more efficiently

Question 8

Why does larger SA:Vol ratio allow cells to work more efficiently?

Answer 8

For every unit that requires nutrients or produces waste, there is a membrane to serve it. Metabolic reactions occur on the membranes.
The diffusion pathways are more efficient. This is because molecules do not have to travel so far to get in& out of the cell, so it takes less time (and if these molecules are diffusing by active transport) they require less energy

Question 9

Where are chromosomal DNA located in prokaryotes?

Answer 9

Naked DNA, located in the region of the cytoplasm called the nucleoid.

Question 10

Describe chromosomes in prokaryotes

Answer 10

Single circular chromosomes of ‘naked’ DNA

Question 11

Describe the function of the cell wall in plants

Answer 11

Semi-rigid structure outside the plasma membrane
Composed mainly of cellulose
Supports cell & limits its volume
Prevents excessive water uptake

Question 12

What is the cell wall composed of?

Answer 12

Mainly of cellulose

Question 13

What does chlorophyll contain

Answer 13

dense stacks of membranes (Grana) within a colourless fluid which is much like cytosol

Question 14

Why do cells & tissues specialised for gas or material exchange increase their surface area?

Answer 14

to optimise the transfer of materials

e.g microvilli in the small intestine

Question 15

What will happen if the metabolic rate is greater than the rate of exchange of vital materials & wastes?

Answer 15

The cell will eventually die

Question 16

What makes stem cells suitable for therapeutic uses?

Answer 16

Their ability to divide & differentiate along different pathways

Question 17

Do single-celled organisms usually have a small or large SA?

Answer 17

small SA

Question 18

How do specialised cells & tissues arise?

Answer 18

through differentiation, which is regulated through differential gene expression

Question 19

What produces the emergent property of metabolism in a cell?

Answer 19

biochemical reactions in all cells

Question 20

What are glycolipids?

Answer 20

phospholipids w attached carbohydrates by a covalent bond

Question 21

What is the function of a glycolipid?

Answer 21

Cell signalling, cell-cell recognition & help stabilise membrane structure

Question 22

What makes cholesterol attracted to the phospholipid bilayer?

Answer 22

It has a hydroxyl group which attracts it to the phosphate heads, and has a hydrophobic tale which is attracted to the hydrophobic tails of the bilayer

Question 23

What type of diffusion do channel proteins allow?

Answer 23

facilitated diffusion

forms a pore through the hydrophobic interior of the membrane

Question 24

What type of transport do carrier proteins allow?

Answer 24

facilitated & active

Question 25

Nutrition in plants

Answer 25

involves making organic molecules, during photosynthesis

Question 26

What is the Golgi apparatus comprised of?

Answer 26

made up of flattened sacked pouches called cisternae | membrane-bound organelle

Question 27

What phospholipid molecule is polar?

Answer 27

the phosphate head

Question 28

What does semi-permeable mean?

Answer 28

some substances & molecules can pass through the membrane, but other cannot.

Question 29

What is a phospholipid bilayer?

Answer 29

a double layer of phospholipids that makes up a plasma membrane

Question 30

Which has higher SA: Vol ratio, prokaryotes or eukaryotes?

Answer 30

prokaryotes

Question 31

What does the potency of a stem cell depend on?

Answer 31

depends on their origin

Question 32

How many genes are there in a humans genome?

Answer 32

25000

Question 33

What are the substances that need to be transported into all kinds of animal cells for them to survive?

Answer 33

oxygen glucose water

Question 34

How many specialised cell types are there to be recognised in humans?

Answer 34

200

Question 35

What are the features of chloroplasts

Answer 35

surrounded by a double membrane | vary in shape but are usually spherical

Question 36

Nutrition in animals & fungi

Answer 36

involves the absorption of organic matter

Question 37

What is nutrition?

Answer 37

the intake of nutrients which may take different forms in different organisms

Question 38

What is metabolism?

Answer 38

chemical processes that occur within a living organism to sustain life

Question 39

Growth

Answer 39

irreversible increase in size or shape that occurs over a period of time

Question 40

Excretion

Answer 40

the removal of waste products of metabolism & other unimportant materials from an organism

Question 41

Response

Answer 41

response to a stimulus, a reaction the living organism gives to changes in the external environment

Question 42

Homeostasis

Answer 42

maintenance of a constant internal environment by regulating internal cell conditions

Question 43

Reproduction

Answer 43

the production of an offspring either sexually or asexually, to pass on genetic material to the next generation

Question 44

Cells are the smallest units of life, explain this

Answer 44

a cell is the basic unit capable of carrying out all the functions of a living organism

Question 45

Cells come from pre-existing cells, explain this

Answer 45

cells do not show spontaneous generation

Question 46

What are the certain common features of cells?

Answer 46

plasma membrane cytoplasm DNA

Question 47

Why is a virus a non-living thing?

Answer 47

because it cannot carry out all of the processes of life

Question 48

Viruses

Answer 48

has a protein coat & has genetic material (DNA/RNA) they do not metabolise or reproduce- these functions are carried out by the infected host cells they do not have a cellular structure

Question 49

What is a paramecium?

Answer 49

a unicellular organism that performs all the 7 functions of life in that one cell

Question 50

Extracellular components

Answer 50

salt, amino acids, sugar, neurotransmitters & water

Question 51

Why do cells differentiate?

Answer 51

for emergent properties

Question 52

Only plant cell organelles

Answer 52

Central large vacuole Chloroplasts Cell wall

Question 53

Nucleolus

Answer 53

part of the nucleus which is involved in the production of ribosomes

Question 54

Increase volume=

Answer 54

increase metabolic reactions

Question 55

What is diffusion?

Answer 55

movement of molecules moving from an area of higher concentration to an area of lower concentration

Question 56

Does a cell vs a body of cells have the same properties?

Answer 56

no

Question 57

How to identify a mitochondria on a microscope

Answer 57

by the lines of a membrane

Question 58

does phospholipid bilayer have a single membrane?

Answer 58

yes, except for if its 2 phospholipid bilayers

Question 59

besides nucleus, what other organelles contain DNA?

Answer 59

mitochondria, chloroplasts, both organelles are able to survive & replicate themselves outside of the cell

Question 60

What organelle helps w nuclear division?

Answer 60

centrioles