plant not cottegecore biology

Question 1

what is the xylem made of?

Answer 1

the xylem vessels are long tubes of cells that run up the stem of plants

Question 2

what is the xylem and what is it responsible for?

Answer 2

The xylem are the plant vessels and they are responsible for the transportation of water and mineral ions

Question 3

what are the cells of the xylem called?

Answer 3

vessel elements, they are dead and stacked on top of one another, no cell walls —–) creates a tube for water to flow through

Question 4

what are the walls of the xylem lined with?

Answer 4

The walls of the xylem are lined with a waterproof polymer called lignin that also reinforces the walls of the vessel elements for structural support

Question 5

what happens to the water in leaves?

Answer 5

most of it evaporates in a process called transpiration

Question 6

how does the water travel through the xylem?

Answer 6

thanks to the adhesion and cohesion properties of water
tension between the hydrogen bonds and the vessel elements
+
cohesion between the water molecules that helps the molecules pulled upwards to pull others

Question 7

how does the tension process work?

Answer 7

1) the loss of water in the leaves creates pressure in the xylem
2) water in the xylem is pulled upwards towards the leaves thanks to tension

Question 8

what is tension?

Answer 8

Tension is the formation of hydrogen bonds between the water molecules and the walls of the vessel elements

Question 9

what happens to the water potential at the bottom of the plant when water is pulled up

Answer 9

When water is pulled up the stem, the water potential at the bottom of the plant decreases, then water diffuses to the roots via osmosis

Question 10

what are the phloem and what are they responsible for?

Answer 10

Phloem are plant vessels and they are responsible for transporting sugars

Question 11

what are sieve tube elements?

Answer 11

Sieve tube elements are the many cells on top of one another cells that make up the phloem vessel

Question 12

what do sieve tube elements look like? (aka what do they have and are)

Answer 12

They are living cells that contain a cytoplasm but no nucleus, their walls are made of cellulose

Question 13

what are companion cells?

Answer 13

Companion cells perform the metabolic functions that maintain the sieve tube elements alive.
They have a nucleus, ribosomes, mitochondria and ReR

Question 14

what are sieve plates?

Answer 14

Sieve plates have large pores that allow the sap and sugars to be transported through the sieve tube elements.

Question 15

Define translocation

Answer 15

The movement of organic molecules (sugars like sucrose and amino acids) within the phloem

Question 16

What is transported in the phloem and in which direction?

Answer 16

The substances can be moved in two directions (differently from the xylem which has only 1),
-from the leaves to he roots, transporting sugars and amino acids for growth, energy storage or to turn them into polysaccharides like starch
-from leaves to buds, developing flowers and their seeds, fruit

Question 17

what is the name of the type of cell from which the product of photosynthesis move out?

Answer 17

source, ex leaf cell

Question 18

how is the cell between the sieve tube and the source called?

Answer 18

transfer cell

Question 19

what are the characteristics of the transfer cell?

Answer 19

-have many infoldings of cell wall and cell membrane to increase the surface area
-have mitochondria for energy as it is required o transport the material
-numerous plasmodesmata to link their cytoplasm with that of the adjacent cells

Question 20

how do things move along the phloem?

Answer 20

The difference in pressure between the loading (from source-transfer) to sieve tubes and the unloading (to transfer-sink) causes mass flow along the tube

Question 21

what is the function of transfer cells?

Answer 21

load the products of photosynthesis from the source to the sieve tube elements

Answer 22

the solutes are loaded in the phloem, increasing it’s concentration and drawing the water in by osmosis (from high to low concentration)