Section 2

Question 1

what are the levels of organisation?

Answer 1

Organelles Cells Tissues Organ System

Question 2

What is an organelle

Answer 2

An organelle are tiny structures within cells that have a particular function

Question 3

Give an example of an organelle

Answer 3

mitochondria, vacuole, nucleus

Question 4

What is a cell

Answer 4

A cell is a basic organ of life that are specialised to carry out a particular functionThe organelles work together to carry out a particular function.

Question 5

Give an example of a cell

Answer 5

red blood cell - carries oxygenegg cell

Question 6

What is a tissue

Answer 6

A tissue is a group of cells working together to carry out a particular function

Question 7

Give an example of a tissue

Answer 7

palisade layer, nerve, muscle

Question 8

What is an organ

Answer 8

a group of tissues working together to carry out a particular function

Question 9

give an example of an organ

Answer 9

lungs, heart,stomach

Question 10

What is a system

Answer 10

a group of organs working togehter to carry out a particular function

Question 11

give an example of a system

Answer 11

digestive systemreproductive systemexcretory system

Question 12

Mitochondria

Answer 12

used for respiration (energy release)

Question 13

Nucleus

Answer 13

has DNA which controls all cell functions

Question 14

Cytoplasm

Answer 14

where all chemical reactions occur

Question 15

Cell membrane

Answer 15

semi-permeablecontrols what enters and exits the cell

Question 16

Cell wall

Answer 16

gives the plant structure, prevents it from bursting

Question 17

vacuole

Answer 17

cell sap storeinvolved in turgor pressure

Question 18

chloroplasts

Answer 18

used for photosynthesis

Question 19

Which chemical elements are present in Carbohydrates?

Answer 19

carbonhydrogenoxygen

Question 20

Which chemical elements are present in Proteins?

Answer 20

carbonhydrogenoxygennitrogensulphur

Question 21

Which chemical elements are present in Lipids?

Answer 21

carbonhydrogenoxygen

Question 22

what is the test for glucose?

Answer 22

Add Benedict’s reagent (blue) into a sample of suspected glucose. Heat the sample. If the sample changes colour from blue –> green –> yellow –> orange –> brick redthen glucose is proven

Question 23

what is the test for starch?

Answer 23

Add Iodine solution into a sample of suspected starch. If the sample changes colour from yellow/brown –> blue/black then starch is proven

Question 24

What is the definition of an enzyme?

Answer 24

An enzyme is a biological catalyst. They speed up reactions without being used up themselves.

Question 25

What happens to the enzyme activity if the temperature is increased up to 40 degrees?

Answer 25

Increasing the temperature increases the kinetic energy of the enzymes. This means that there are more collisions between the active site and the substrate. The reaction will therefore take place more frequently

Question 26

What happens to the enzyme activity if the the temperature is increased past 40 degrees?

Answer 26

The enzyme denatures/changes shape;The active site does not fit the substrate;no products are formed;

Question 27

What happens to the enzyme activity if the pH is not at it's optimum?

Answer 27

The pH levels interfere with the bonds that hold the enzyme together. This changes the state of the acitve site and denatures the enzyme.

Question 28

What is osmosis

Answer 28

Osmosis is the net movement of water moelcules across a partially permeable membrane from a region of high water potential (lots of free water) to a region of lower water potential (less free water)

Question 29

What is diffusion

Answer 29

Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration (randomly)

Question 30

What is active transport

Answer 30

Active Transport is the specific movement of particles with or against a concentration gradient using energy released during respriation across a membrane using a specific protein pump

Question 31

What is photosynthesis? What is the balanced chemical equation for photosynthesis?

Answer 31

Photosynthesis is the conversion from light energy to chemical energy to produce food for plants. 6CO2 + 6H2O ------> C6H12O6 + 6O2

Question 32

How is temperature different as a factor affecting the rate of photosynthesis in comparison to CO2 or light

Answer 32

Temperature increases and so does photosynthesis up to a point. If the temperature is too high (about 45 degrees) the plant's enzymes will denature so the rate of photosynthesis decreases. By contrast, as light and Carbon dioxide increase the rate of photosynthesis also increases. Beyond a certain point these two are not limiting factors.

Question 33

How are leaves adapted for photosynthesis? | CLUNS W

Answer 33

- chloroplasts found the palisade layer near the top of the leaf where they can get the most light - large surface area exposed to light - upper epidermis is transparent which allows more light to be recieved by the chloroplasts. - Waxy cuticle helps to reduce water loss by evaporation - Network of vascular bundles - Lower surface full of little holes called stomata which lets CO2 diffuse directly into the leaf