chapter 2 - basic components of living systems

Question 1

what are the typical sizes of eukaryotic cells and prokaryotic cells

Answer 1

eukaryotic - 10-100um
prokaryotic - 1-5um

Question 2

which types of cells have golgi apparatus

Answer 2

all eukaryotic, no prokaryotic

Question 3

describe the differences in the DNA in prokaryotic and eukaryotic cells

Answer 3

eukaryotic = linear, in the nucleus, associated with histone proteins forming chromatin. when preparing for cell division, chromatin condenses to chromosomes.

prokaryotic = circular, with small circular pieces called “plasmids”, not bound by a membrane. same fundamental DNA as eukaryotes but packaged differently

Question 4

what cells are cell walls present in and what are they made of?

Answer 4

Animal cells - NO CELL WALL
Plant cells - CELLULOSE
Fungi - CHITIN
Bacteria - PEPTIDOGLYCAN

Question 5

how and where do cells carry out respiration (eukaryotic vs prokaryotic)

Answer 5

eukaryotic - glycolysis in cytoplasm, aerobic respiration in mitochondria

prokaryotic - glycolysis in cytoplasm, aerobic respiration on mesosome

Question 6

what is the function of the mesosome in prokaryotic cells?

Answer 6

production of ATP, Aerobic respiration

Question 7

what are 5 roles of the cytoskeleton in cell

Answer 7

1. provides strength and stability
2. determines/ changes shape
3. movement of organelles
4. attach to/ hold organelles in place
5. make up centrioles/ spindle fibres

Question 8

how do prokaryotic and eukaryotic cells reproduce?

Answer 8

prokaryotic = binary fission
eukaryotic = asexual or sexual

Question 9

describe the structure and roles of the centrioles

Answer 9

in animal ce3lls, there are two centrioles outside the nucleus, at right angles to each other
hollow cylinders around 0.4um long
made up tubulin forming bundles of microtubules
produce the MITOTIC SPINDLE for cell division and are involved in the formation of cilia and undulipodia

Question 10

what are cilia and undulipodia?
what cells are they present in?

Answer 10

part of the cytoskeleton and consist of microtubules arranged in a cylinder as a 9+2 formation
cilia are short and abundant on cells <10um - beat rhythmically

undulipodia are long >10um and usually singular - cause the cell to move.

present in some eukaryotic cells

Question 11

what name is given to the structures which penetrate the walls of adjacent plant cells?

Answer 11

plasmodesmata

Question 12

cells in a culture will absorb amino acids from surrounding medium, if radioactively labelled glycine is provided. which organelle with radioactivity be found in first?

Answer 12

ribosomes - glycine is an amino acid, protein synthesis

Question 13

intestinal epithelial cells have observable “brush borders” on their cells, what are they?

Answer 13

microvilli

Question 14

when mitochondria is extracted, why is it usually kept in a 0.24moldm^-3 sucrose solution?

Answer 14

prevents mitochondria from changing structure - the sucrose solution maintains an equilibrium so the organelle doesn’t shrink or burst

Question 15

out of:
1. a virus
2. a phagocyte
3. a red blood cell
4. a bacterium
which has the lowest surface area to volume ratio?

Answer 15

B - biggest out of the four

Question 16

what is the approximate size of a lysosome?

Answer 16

1um

Question 17

out of
1. lysosomes
2. mitochondria
3. ribosomes
4. starch grains
which can be clearly seen under the high power of a light microscope?

Answer 17

only starch grains

Question 18

a tadpole’s tail is gradually broken down during metamorphosis into an adult frog, which organelle increases in number in the cells of the tail at this time?

Answer 18

lysosomes - contain hydrolytic enzymes

Question 19

put these in order of size
1. mitochondria
2. chloroplast
3. nucleus

Answer 19

smallest = mitochondria
middle = chloroplast
largest = nucleus

Question 20

what is an eyepiece graticule and what is its function

Answer 20

a glass piece with a fine scale, placed inside the eyepiece of a microscope. the size of the eyepiece graticule allows you to calibrate the microscope at different objective lenses by using a stage micrometre

Question 21

out of
1. bone marrow
2. blood
3. lymph nodes
where do stem cells divide?

Answer 21

only in the bone marrow

Question 22

haematopoietic stem cells give rise to various blood cells, what type of stem cells are they?

Answer 22

multipotent - form only a range of cells from a specific tissue - e.g. haematopoietic stem cell only form blood cells

Question 23

define pluripotent ( in terms of stem cells)

Answer 23

can form all tissue types but not a whole organism

Question 24

how do stem cells replace damaged cells in the skin tissue of adults?

Answer 24

they divide by mitosis to produce cells that can differentiate

Question 25

Which cell component forms pinocytic vesicles

Answer 25

Plasma membrane

Question 26

What is the approximate diameter of a mammillary red blood cell

Answer 26

7um

Question 27

Which out of:
Mitochondria
Golgi apparatus
Nucleolus
Pinocytotic vesicles
Would be more prominent in a secretory cell

Answer 27

Golgi apparatus