A2.2.7-14 Cell Structures

Question 1

state the functions of life

Answer 1

the ability to…

Metabolism- the sum of all the chem rxn that occur within an org

Reproduction- to produce offspring

Sensitivity (response to stimuli)- as the env changes, org adapts

Homeostasis- Maintenacne of a constant internal env

Excretion- release materials not needed or harmful into the surrounding env

Nutrition-acquire energy and materials needed to maintain life

Growth-development of an organism

Question 2

do plant cells/animal/fungal cells have chloroplasts

Answer 2

yes no no

Question 3

do plant/animal/fungal cells have centrioles or centrosoems

Answer 3

centrosomes only/ both/ centrosomes only

Question 4

What are hyphaes

Answer 4

filaments produced by some multicellular fungi

consist of chains separated by cross walls with pores that allow various organelles and cytoplasm to flow from cell to cell

some fungi produces hyphae w/o cross walls, resulting in a single mass of cytoplasm (one cell) with more than one nuc

Question 5

What special functions do pholem sieve tube elements have

Answer 5

they have a specialized function allowing transportation within a multicellular plant

these cells have end walls with pores, minimal cellular components (e.g. nuclei, ribosomes, cytoskeleton, cytoplasm)

these are connected end to end, forming tube structures. These can only remain alive w the help of companion cells (which maintain a close connection w the sieve tube elements)

Question 6

What specialized functions do red blood cells have

Answer 6

carrying oxygen throughout the body
contain substantial amounts of a molecule called haemoglobin (globular protein), which easily combines w oxygen

they are shaped to allow a large SA for the absorption and release of oxygen

no nuc, allows them to carry even more oxygen

Question 7

What specialized functions do skeletal muscle cells have

Answer 7

has specialized proteins arranged in bands that contract and relax, allowing for body movement

the presence of cell membranes is limited, resulting in large tubular cells with multiple nuclei, allowing more coordinating protein molecules

Question 8

What specialized functions do nerve cells have

Answer 8

long, thin with branched connections at each end to transmit electrical impulses

Question 9

What specialized functions do sperm cells have

Answer 9

many mitochondria and a tail allowing movement and a head with a tip capable of producing an enzyme that facilitates penetration of an egg cell

Question 10

what theory explains the progession of cells from a simple non compartmentalized prokaryote to a complex highly compartmentalized eukaryote.

Answer 10

the endosymbiotic theory!

Question 11

Outline endosymbiotic theory

Answer 11

a larger cell that had a nucleus and was capable of sexual reproduction engulfed a smaller prokaryotic cell that could produce energy, these two cells developed a mutually beneficial (symbiotic) relationship forming a single organism, the smaller engulfed prokaryote then went through a series of changes to become a mitochondrion

with this process the larger cell helped the bacteria prokaryote by providing protection and carbon compounds, the smaller prokaryote (after changes) became specialized to provide ATP

Question 12

WHat are some characteristics of mitochondria that support the endosymbiotic theory

Answer 12

similar size as most bacterial cells

divide by simple binary fission, as do most bacterial cells

divide independently of the host cell

own 70s ribosomes, as prok ribs are

produce their own proteins w therse ribs

own DNA, in a circular ring

two membs on exterior, which is consistent w engulfing process

inner membrane w a composition like that of prok mems, the outer is more like euk cell memb

RNA present in mitochondrial ribosomes that resembles the RNA in prok ribs

they also have DNA code that more closely resembles bacteria than euk cells

Question 13

How do chloroplasts in plant cells provide evidence for endosymbiosis

Answer 13

chloroplasts evolved from free living photosynthetic bacteria that were engulfed by a euk host cell

Question 14

more DNA two orgs have in common , the closely related they are to one another

Question 15

what play a major role in the formation of compartments (compartmentalization) and allow for efficient reactions and processes to proceed

Answer 15

membranes

Question 16

do cells in the same multicellular organism have the same genetic information

Answer 16

yes (same DNA, different expressions)