nutrients and gas requirments

Question 1

what is an autotroph

Answer 1

is an organism that can make its own food e.g. plants

Question 2

outline the root systems

Answer 2

transpiration stream: plants obtain water through branching networks of fine roots and root hairs, water is absorbed from the soil via root hairs of plants, water then travels from the roots to all parts of the plant through xylem

Question 3

what is the purpose of plants having finer and finer roots

Answer 3

this results in a large surface area to volume ratio, increasing absorption of nutrients

Question 4

what is the transpiration stream

Answer 4

a process that draws the water up the stem and helps pull more water from the soil into the plant

Question 5

what is xylem

Answer 5

carries water and mineral ions in one direction (roots to leaves)

Question 6

what is the stems role in the shoot system

Answer 6

the stem provides structural support and a transport pathway between the roots and leaves

Question 7

what is vascular tissues and where is it found

Answer 7

found in the stem, they are groups of tubes conduction material comprised of phloem (sucrose), xylem (water), and cambium

Question 8

what is cambium

Answer 8

area of cell division, where new xylem and phloem are formed

Question 9

In plants have a vascular system, describe how water (CATT) is moved throughout the plant.

Answer 9

C= cohesion (water molecules are attracted to each other, sticking together)
A= adhesion (when the water sticks to the sides of the tube)
T= tension caused in the lead by the water lost during transpiration causes water to move up and replace lost water
T= transpiration (water is pulled up the xylem cells, by the evaporative pull of transpiration)

Question 10

draw the structure of a leaf

Answer 10

look at notes

Question 11

describe the function of waxy cuticle in a leaf structure

Answer 11

a waxy cuticle minimises water loss from the leaf (reflect sunlight → not too much absorption)

Question 12

describe the function of palisade cells in a leaf structure

Answer 12

palisade cells containing many chloroplasts are lined up vertically near the upper surface of the leaf to absorb sunlight they are at the top to increase photosynthesis

Question 13

describe the function of spongy mesophyll in a leaf structure

Answer 13

spongy mesophyll cells are loosely and irregularly organised to all easy movement of gases through the leaf (help with gas exchange)

Question 14

describe the function of transport tissue in a leaf structure

Answer 14

transport tissue in the leaf is organised into vein. This provides support as well as a pathway for the movement of water and the products of photosynthesis (vascular bundle)

Question 15

describe the function of guard cells in a leaf structure

Answer 15

guard cells, which are often more numerous on the underside of the leaf, change shape to open and close ‘pores’ known as stomata

Question 16

describe the function of stomata in a leaf structure

Answer 16

the gases oxygen and carbon dioxide are exchanged between the inside and outside of the leaf through stomata. if in a dry environment, stomata is closed to preserve water for photosynthesis

Question 17

In plants have a vascular system, describe how glucose (translocation) is moved throughout the plant.

Answer 17

sugars (glucose and sucrose) are made by photosynthesis in the source (leaf). the transported to phloem by active transport, sugars move to the next phloem cell through the sieve and reach the sink (their destination) to then undergo respiration

Question 18

what is phloem comprised of

Answer 18

sieve cells joined end to end to form a series of connecting tube
sieve plate joins each sieve cell -> no cell wall at plate just membrane
the major metabolic functions are carried out by companion cell next to sieve cell

Question 19

what is phloem

Answer 19

transport sugars (glucose and sucrose), amino acids and hormones in any direction around the plant

Question 20

how does an MRI determine plant structure

Answer 20

Magnetic resonance imaging (MRI) is a medical imaging technique that uses a magnetic field and computer generated ration waves to create detailed 3D images of organs (leaf) and tissues

Question 21

how does an PET determine plant structure

Answer 21

Positron emission tomography (PET) scan is an imaging test that uses a special dye containing radioactive tracers

Question 22

how does an x-ray computed micrograph determine plant structure

Answer 22

A sample of plant tissue positioned in and x-ray beam is rotated and hundreds of images are recorded and converted into a 3D image

Question 23

where is gas exchange in a leaf

Answer 23

stomates are the sight of gas exchange in a leaf, carbon dioxide enters the stomates and oxygen leaves the leaf

Question 24

what is the function of alveoli in mammals

Answer 24

most important part of the respiratory system, their function is to exchange oxygen and carbon dioxide gas molecules to and from the bloodstream

Question 25

where is alveoli location in mammals

Answer 25

at the end of the bronchioles

Question 26

outline the respiratory system in fish

Answer 26

made from thousands of gill filaments = increase SA and counter-current blood flow = increase diffusion gradient
water passes through gills and oxygen is removed

Question 27

outline the respiratory system in frogs

Answer 27

air moves in and out by movements of the mouth and buccal cavity, air is squeezed into the lungs where gas exchange takes place, air then moves back out through nostrils

Question 28

outline physical digestion

Answer 28

the physical breakdown of food
teeth: break food into smaller pieces by cutting, tearing, chewing
stomach: churning motion breaking down bolus into smaller pieces to increase SA so enzymes can act on it

Question 29

outline chemical digestions

Answer 29

process of using digestive enzymes to chemically break down food into simple forms (carbohydrates into glucose, proteins into amino acids, lipids into fatty acids/glycerol)

Question 30

what are the nutrient and gas requirements of autotrophs

Answer 30

make own carbohydrate (glucose) via photosynthesis and vitamins
obtain minerals and water from soil
get carbon dioxide from air, some oxygen from soil

Question 31

what are the nutrient and gas requirements of heterotrophs

Answer 31

obtain carbohydrates, water and minerals from diet
can make some minerals and need to obtain others
oxygen from air

Question 32

what are the similarities

Answer 32

both require glucose for energy and for respiration