water to land

Question 1

what its the ancestor of land plant

Answer 1

green algae its the ancestor of land plants

Question 2

what are the modification that came about to allow water balance and gas exchange

Answer 2

cuticle: protective ater resistant to minimise water loss
garmertangia:protective covering for gametes which are antherdia and archegonia
roots: extracting water and nutrient for soil
vascular system: for äter transport and nutrient transport
tissue: structural support (xylem)

Question 3

explain on cuticle

Answer 3

waxy hydrophobic coating. prevents diffusion of water. protects against uv radiation, desiccation and pathogens.

Question 4

hope do plants exchange gases

Answer 4

stomata. analogous to a mouth. open and close in response to water/light availability. balances gas exhange with water loss.

Question 5

how do plant adapt to arid conditions

Answer 5

sunken stomata to minimise the water evaporative gradient. this is how we get around the waxy cuticle problem

Question 6

gametangia

Answer 6

achergonium: on top of the moscametophyte
antheridium: motile sperm. water splashes to carry it to the egg.

Question 7

purpose of xylem

Answer 7

transports water and mineral salts from roots, stems and leaves. its a passive transpirational pull

Question 7

purpose of phloem

Answer 7

transports manufactured food (sucrose and amino acids from leaves, other parts of the plants

Question 8

two types of growth

Answer 8

primary growth and secondary growth
primary growth: xylem on the inside and phylum on the outside. there is a ring or cambian tissue which are stem cells that pumps out new cells and they’re in concentric circle (dicotts)
secondary growth: allows plants to become large which supports increased height. the production of woody tissue (comes from lignin) by vascular cambium is a characteristic of some seed plants.
primary growth is growing up and secondary growth is going out

Question 9

what is wood Made from

Answer 9

lignin. the cambium links up and pups cells on the outside and inside. the inside is secondary xylem and is the wood.

Question 10

what are microgametophytes

Answer 10

pollen containing males gametes. sporophyte makes microspores and develops through endosperm into a microgametophyte and that delivers to sperm.

Question 11

how do flowering plants become pollinated.

Answer 11

abiotic and biotic pollination

Question 12

where are the microspores

Answer 12

in the stamen

Question 13

where does the pollen land to travel to the ovules

Answer 13

stigma

Question 14

what do the colour of the flowers tell you

Answer 14

red: pollinated by bird
yellow: bees
white:moths

Question 15

pollinator vs hanging out

Answer 15

structure to collect pollen. they should also have the pollen at the top. you need to see them move the pollen from one male flower to the stigma of another female flower to be considered a pollinator

Question 16

whats the role of the fruit

Answer 16

contains the embryo or the seeds. dry fruits are passively dispersed or wind dispersed

Question 17

types of skeletons you can have in the water

Answer 17

1. hydrostatic skeletons (fluids)
2. exoskeleton
3. endoskeleton

Question 18

what happened to the hydrostatic skeleton on land

Answer 18

there is less buoyancy and less air density in land. they need to be quite small. some don’t have a covering to prevent them from desiccation so they are limited to moist areas whilst some do.

Question 19

exoskeleton in land

Answer 19

skeleton on the outside and muscle on the inside. stops desiccation. easy for them to move from water to the land. the exoskeleton becomes heavier and whilst its ok in water because of the buoyancy it provides, in land, the more the organism grows and the more the exoskeleton expands, it can crush the internal structures. it therefore limits them in terms of how big they can be.

Question 20

endoskeleton in land

Answer 20

skeleton on the outside and muscles on the inside. they need impervious surface on the outside of the body (skin, scales) to protect them from desiccation. frogs have a permeable surfac.the need to over themselves to mucus or they will be limited to areas that are moist

Question 21

respiratory surfaces in land

Answer 21

protective surface on your body limits gas exchange through skin. reptiles that have scales and are bigger will need a specialised organ to help them perform gas exchange. we don’t want our respiratory system to be dry so they are enclosed in a terrrestial environment. we want to keep it dry because you can only have gas exchange when its moist. so we made internal lungs. meanwhile insects have a tracheal system. the air gets delivered to all parts of the body and is not dissolving into fluid, I t does need to be moist.

Question 22

first animals on land

Answer 22

already had exoskeleton and had gills that’s protected with fleas. this allows the gills to stay moist for a little bit.

Question 23

gamete exchange

Answer 23

water: broadscast (mass spawning, spermcasting, external fertilisation.
in land: air will desiccate the gamete. so instead se d this through spermatophore- a capsule of mass containing sperm cells with a coating that is desiccant resistant eg. cuticle or mucus. its taken up by a female. OR you can create a spermatophore and lead a female to pick it up straight away so it does need to have the cuticle. internal fertilisation through intromittent organ- external organ of a male organisms that is specialise to deliver sperm during copulation. another option is mating.

Question 24

what happens to fertilised egg in land

Answer 24

in water, its floating an water so it doenst desiccate. in land, some animals go back to water to lay their eggs while some create a protective barrier. so like an eggshell or any other coating. the eggshell stops water moving out the egg but still allows gas exchange. another is basically being pregnant. this is known as viviparity.