Plant transport + Homeostasis

Question 1

What do phloem vessels do?

Answer 1

Phloem Vessels transport food materials (mainly sucrose and amino acids) made by the plants from photosynthesis leaves to non-photosynthesising regions in the roots and stem.

Question 2

What do xylem vessels do?

Answer 2

They transport water and minerals from the roots to the stem and leaves

Question 3

Name the structural features of the phloem that are different to the xylem

Answer 3

The cells are living cells and are not hollow. Substances move from cell to cell through pores in the end walls of each cell

Question 4

Name the structural features of the xylem

Answer 4

It is composed of dead cells which form hollow tubes. Xylem cells are strengthened by lignin and so are adapted for the transport of water in the transpiration stream.

Question 5

Where are the xylem and phloem arranged in a plant to from a plant system and what is it called?

Answer 5

Arranged throughout the root, stem and leaves in groups called vascular bundles

Question 6

How are the root hair cells adapted?

Answer 6

They increase surface area to volume ratio significantly, they increase the rate of absorption of mineral ions by ACTIVE TRANSPORT

Question 7

Where do root hair cells grow ?

Answer 7

They grow between soil particles and absorb water and minerals from the soil.

Question 8

What are root hair cells?

Answer 8

Root Hairs are single-celled extensions of epidermis cells in the root

Question 9

How is water absorbed by root hair cell?

Answer 9

Water is absorbed by osmosis

Question 10

Define transpiration

Answer 10

The loss of water vapours from the parts of the plant that are above ground(leaves, stem, flower)

Question 11

How does transpiration work?

Answer 11

Evaporation of water molecules from the surface of mesophyll cells to air space (water leaves from the stomata)

Question 12

Describe the process of transpiration

Answer 12

As water evaporated from the leaf, it lowers water potential of cells near the stomata. Water moves from cell to cell by osmosis and evaporates. Water osmoses into the root hair cell from the soil, which osmoses into the xylem. The column of water is pulled up, due to cohesion and back into the leaf.

Question 13

What variables effect the rate of transpiration

Answer 13

Wind speed, humidity, temperature and light intensity.

Question 14

What are the two key functions of the urinary system?

Answer 14

• To filter waste products from the blood and expel it as urine
• To control the water levels of the body (osmoregulation)

Question 15

Name the two blood vessels which connect to the kidney.

Answer 15

Renal artery // Renal vein

Question 16

Name the tubes which joins the kidneys to the bladder

Answer 16

The ureters

Question 17

What is the purpose of the urethra in the urinary system

Answer 17

Carries urine from the bladder to outside the body

Question 18

Name 3 components of urine

Answer 18

Excess water, salts, urea

Question 19

Name and define the three regions of the kidney

Answer 19

Cortex - the outermost region
Medulla - the inner section of the kidney
Renal pelvis - the tube linking the kidney to the ureter

Question 20

Where are nephrons found in the kidney

Answer 20

Nephrons are located between the cortex and the medulla

Question 21

Which part of the nephron is found in the medulla

Answer 21

Loop of Henle

Question 22

Which structure is found within the Bowman’s capsule

Answer 22

Glomerulus

Question 23

Explain ultrafiltration

Answer 23

The glomerulus is composed of a knot of small capillaries
This has a small volume so a very high pressure on the blood
The pressure forces out smaller molecules which are known as the filtrate
The substances in the filtrate are glucose, lots of water, urea and salts

Question 24

Where does the filtrate go in the kidney after being filtered out of the glomerulus

Answer 24

Into the bowman’s capsule, then into the proximal convoluted tube

Question 25

What occurs in the proximal convoluted tube?

Answer 25

Glucose is reabsorbed into the blood through active transport

Question 26

What occurs in the loop of Henle?

Answer 26

Salts are reabsorbed by diffusion
Water is reabsorbed by osmosis
This is because the surrounding medulla is salty
The remaining filtrate continues into the distal convoluted tube

Question 27

What is the role of the collecting duct

Answer 27

Gathers remaining fluid to form urine which then goes to the ureter