Module 2

Question 1

Level of organisation in organisms

Answer 1

Organelles  cells  tissues  organs  systems  organisms

Question 2

Unicellular organisms

Answer 2

• Contain only one cell responsible for all life processes
• Simple structure
• Limits metabolic reactions
• Large surface area for all substances to diffuse across

Question 3

Colonial organism

Answer 3

• Cells that form a cooperative group (colony) but can survive on their own
• Could be classed as a single celled organism
• More efficient as a colony
• EXAMPLE: Blue-bottle

Question 4

Multicellular organism

Answer 4

• Made up of different types of cells
• Similar cells grouped together that communicate to perform specialised functions that combine together for efficient functioning
• Rely less on diffusion and are less efficient
• All cells have the same DNA
• Could not survive by themselves
• EXAMPLE: Animals and Plants

Question 5

Cell differentiation

Answer 5

less specialised cell changes to become a specialised to carry out specific functions. This makes them more efficient.

Question 6

Cell specialisation

Answer 6

specific function which a cell has, determined by their physiology and cellular structures. They develop suitable structural features which allow them to carry out their functions and this makes them structurally different from other types of cells.

Question 7

Skeletal muscle

Answer 7

long and have striation which are caused by the arrangement of the actin and myosin in them. They are attached to the bones and they cause movement.

Question 8

Cardiac muscle

Answer 8

fibres are present in the heart and also have striations, the individual cells have connection junctions that are necessary or the coordinated beating of the heart.

Question 9

Smooth muscle

Answer 9

do not have striation and their contractions push substances through specialised organs such as the gastrointestinal tract, the blood vessels and the urethra which leads from the bladder.

Question 10

Fish respiration

Answer 10

• Water enters the fish
• Water is pumped through gills
• Oxygen diffuses in and out of capillaries
• Water exits the fish

Question 11

Insect respiration

Answer 11

• Use trachea for gas exchange
• Instead of lungs, insects breathe with a network of tiny tubes called tracheae. Air enters the tubes spiracles and the air then diffuses down the tracheae

Question 12

Reptile respiration

Answer 12

• Gas exchange in alveoli
• When its mouth is full of air, the reptile will push the air down into the lungs.
• The nostrils are then closed and the floor of mouth is raised, forcing the air into the lungs for gas exchange.

Question 13

4 plant organs

Answer 13

roots, leaves, stem, flower

Question 14

Function of nasal cavity

Answer 14

the sticky mucous membrane lining the nasal cavity traps dust particles, and tiny hairs called cilia help move them to the nose to be sneezed or blown out.

Question 15

Function of nose

Answer 15

air is inhaled into the body through the nose

Question 16

Function of pharynx

Answer 16

enables you to swallow and is a pathway for food

Question 17

Function of tongue

Answer 17

vital for chewing and swallowing food

Question 18

Function of larynx

Answer 18

voicebox which helps you speak

Question 19

function of trachea

Answer 19

windpipe which provides air to and from the lungs

Question 20

function of lungs

Answer 20

conducts gas exchange for respiration

Question 21

function of bronchi

Answer 21

shuttle air to and from the lungs – highways for gas exchange.

Question 22

function of bronchioles

Answer 22

ensure that incoming air is supplied to the alveoli

Question 23

function of alveoli

Answer 23

exchange oxygen to carbon dioxide in the bloodstream

Question 24

What is the diaphragm

Answer 24

thoracic muscle that lays beneath the lungs and aids in inhalation/exhalation

Question 25

function of nervous system

Answer 25

To coordinate bodily function by passing electrochemical signals, to detect and respond to external stimuli

Question 26

Organs in nervous system

Answer 26

Brain, sensory organs (eyes, ears, tongue, skin), nerves

Question 27

Function of digestive system

Answer 27

To breakdown and absorb food

Question 28

organs in digestive system

Answer 28

Stomach, intestines, mouth, liver

Question 29

Excretory system function

Answer 29

To rid the body of metabolic wastes

Question 30

Excretory system organs

Answer 30

Kidney, bladder, urethra, ureters

Question 31

Cellular respiration in plants

Answer 31

Break down sugar and turn it into energy - mitochondria

Question 32

Photosynthesis in plants

Answer 32

Harness energy from sunlight and turn it into chemical energy - chloroplast

Question 33

What is the stomata

Answer 33

``` • Tiny pores that cover epidermis • Gas enters and leaves • Each has a pair of guard cells - Open and close throughout day - Have chloroplast - Reduce water loss ```

Question 34

Heterotrophs

Answer 34

Organisms that feed on others because they cannot provide their own energy supply

Question 35

Autotrophs

Answer 35

Organisms that can make their own energy and do not depend on others.

Question 36

5 steps of nutrition in heterotrophs

Answer 36

1. Ingestion – intake of food (eating) 2. Digestion – breakdown of food into soluble molecules that can be easily absorbed 3. Absorption – basic units of food absorbed into the bloodstream 4. Assimilation – turning the ‘food’ into tissue 5. Egestion – elimination of wastes

Question 37

Mechanical digestion

Answer 37

(Physical) – chewing, churning, moving | Involves physically breaking the food into smaller pieces.

Question 38

Chemical digestion

Answer 38

(Enzymes) - Break down large complex molecules into simpler molecules

Question 39

Xylem Structure

Answer 39

Lignin provides strength to stop the vessels from collapsing. Tracheids transport water and are elongated with end walls that taper to a point and also impregnated with lignin Fibres are also elongated and lignified, providing support to the xylem tissue.

Question 40

Phloem Structure

Answer 40

Phloem – sugar transport tissue in plants Sieve tub elements – living cells without cytoplasm and mitochondria but without other organelles Sieve plates – the perforated transverse walls of the sieve elements which allow sap to flow from one element to the next Companion cells – associated with each sieve element and they are responsible for keeping them alive

Question 41

Cohesion/ Adhesion

Answer 41

The ability of water molecules to stick to other water molecules due to high intermolecular forces

Question 42

Transpiration

Answer 42

Loss of water from plants by evaporation of water vapour through the stoma of plant leaves.

Question 43

Negative pressure

Answer 43

When an area of lower pressure than the other surrounding it. Creates a ‘pulling’ force

Question 44

Translocation

Answer 44

Source – Place that produces or stores sugar (leaves and roots) Sink – Place in need of sugar

Question 45

Function of waxy cuticle in plants

Answer 45

A thin protective outer covering. Protects against water loss.

Question 46

Function of Upper/Lower epidermis in plants

Answer 46

Aid structural support and allow light to pass through.

Question 47

Function of Palisade mesophyll

Answer 47

Primary site for photosynthesis.

Question 48

Function of Spongy mesophyll

Answer 48

Allow gases to diffuse through  secondary site for photosynthesis.

Question 49

Function of Vascular tissue: Xylem cells

Answer 49

Transport water + nutrients upwards from the roots to the rest of the plant.

Question 50

Function of Vascular tissue: Phloem cells

Answer 50

Conduct food from leaves to rest of the plant

Question 51

Function of Guard cells

Answer 51

Cells close the stomata in response to environmental conditions.

Question 52

Function of Stomata

Answer 52

Allow gases to enter and exit. Holes allow loss of water vapour

Question 53

Function of RBC

Answer 53

Transport oxygen, carbon dioxide and haemoglobin

Question 54

Function of WBC

Answer 54

Transports antibody into the plasma to fight pathogens

Question 55

Function of platelets

Answer 55

Clumps blood to control bleeding

Question 56

Function of plasma

Answer 56

Carries nutrients (glucose, amino acids, proteins, ion, waste products and small amounts of carbon dioxide

Question 57

Function of veins

Answer 57

Veins return blood to the heart and have thinner walls than those of the arteries.

Question 58

function of arteries

Answer 58

Arteries carry blood away from the heart with a strong structure that is able to withstand the high pressure in which the blood is moving

Question 59

Function of capillaries

Answer 59

Transfer oxygen and nutrients through blood.

Question 60

Open circulation

Answer 60

* Fluid is not combined to vessels * Circulation is slow * Transports nutrients not oxygen * Found in arthropods e.g. insects and mollusc

Question 61

Closed circulation

Answer 61

* Blood moves through the body enclosed in a network of tubes of different sizes that lead to and away from the heart * Blood circulation is rapid * Nutrients, wastes and gases are carried by blood * Found in larger, active animals e.g. mammals, amphibians, birds and fish