y9 revision 1

Question 1

what is a tissue?

Answer 1

a group of cells with similar structures and functions

Question 2

what is an organ?

Answer 2

a group of tissues working together to perform a specific function

Question 3

what is an organ system?

Answer 3

a group of organs working together to perform a particular function e.g. the digestive system

Question 4

what is an enzyme?

Answer 4

a biological catalyst

Question 5

name the parts of the lungs

Answer 5

trachea, bronchus, bronchiole, alveoli

Question 6

name three blood vessels

Answer 6

arteries ~ carry blood away from the heart
capillaries ~ exchange of materials at the tissue
veins ~ carry blood to the heart

Question 7

define health

Answer 7

health is a state of physical and mental well-being

Question 8

define cancer

Answer 8

cancer is caused by uncontrolled cell growth and division

Question 9

define transpiration

Answer 9

movement of water through a plant

Question 10

define translocation

Answer 10

movement of sap (sugars and salts) through a plant

Question 11

what is the function of bile in digestive system?

Answer 11

1. neutralises acid from the stomach

2. emulsifies fat to increase surface area allowing the enzyme lipase to break the fat down quicker

Question 12

where does digestion start?

Answer 12

digestion starts in the mouth when the salivary glands produce the enzyme amylase

Question 13

name two places where mechanical digestion takes place

Answer 13

1. the mouth the action of teeth starts to breakdown the food
2. the stomach churns the food

Question 14

describe 3 functions of the stomach

Answer 14

1. muscular to churn food
2. produced the enzyme protease
3. produces hydrochloric acid that kills bacteria and allows the protease enzyme to work

Question 15

describe 2 functions of the small intestine

Answer 15

1. produces enzymes (protease, amylase, lipase) to complete digestion
2. digested food is absorbed from the small intestine into the blood

Question 16

Give three adaptions of the small intestine an explain how it increases the rate of diffusion of molecules into the blood

Answer 16

1. thin walls ~ once cell thick, short diffusion pathway
2. good blood supply ~ maintains high concentration gradient
3. villi (folded structure) ~ large surface area

Question 17

describe the function of the large intestine

Answer 17

removes excess water from digested food

Question 18

name three enzymes produced in the pancreas

Answer 18

amylase, protease, lipase

Question 19

name the four main components of blood

Answer 19

red blood cells, white blood cells, plasma, platelets

Question 20

name substances transported in the blood plasma

Answer 20

hormones, proteins, urea, carbon dioxide, glucose

Question 21

describe three adaptions of a red blood cell

Answer 21

no nucleus ~ more space for oxygen
contains haemoglobin ~ bind oxygen
bi-concave disc shape ~ large surface to volume ratio for fast diffusion of oxygen

Question 22

what is the function of platelets?

Answer 22

to form blood clots, prevent the loss of blood and stop wounds becoming infected

Question 23

what is a catalyst?

Answer 23

a catalyst is a substance which increases the rate of reaction without being changed or used up in the reaction

Question 24

explain why enzymes are specific to substrates

Answer 24

the enzyme has an active site which is a specific shape for the substrate this is called the lock and key model. If the substrate doesn’t fit the active site of the enzyme the enzyme cannot breakdown the substrate

Question 25

describe the positive and negative food test for sugar

Answer 25

positive: benedict solution will turn from blue to green, yellow or red depending on how much sugar is in the food. You need to hear this test in a water bath to make this work negative: the benedict solution will stay blue

Question 26

describe the positive and negative food test for starch

Answer 26

positive: Iodine will turn from brown/orange to black/ blue if starch is present negative: if starch is not present iodine will stay brown/orange

Question 27

describe positive and negative food test for proteins

Answer 27

positive: biuret solution will change from pale blue to lilac purple negative: the solution will stay pale blue

Question 28

describe the positive and negative food test for fat

Answer 28

positive: when alcohol is added the solution will turn from colourless/ clear to white and cloudy negative: the solution will stay colourless/ clear

Question 29

name 3 adaptions of the alveoli and explain how this increases the rate of diffusion/ allows fast gas exchange

Answer 29

1. very good supply, this maintains a high concentration gradient 2. thin cell wall ~ one cell thick, short diffusion pathway 3. folded walls to give a large surface area

Question 30

explain why the heart is known as a double circulatory system

Answer 30

two circuits joined together 1. the right ventricle pumps deoxygenated blood to the lungs to take in oxygen, the blood then returns to the heart 2. the left ventricle pumps oxygenated blood around all the other organs of the body. the blood gives up it’s oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again

Question 31

explain the function of valves in the heart

Answer 31

valves make sure the blood pumps in one direction only

Question 32

explain what the pacemaker cells do in the heart

Answer 32

these group of cells located in the right atrium wall produce a small electrical impulse causing the surrounding muscle cells to contract, controlling your resting heart rate

Question 33

state the rate of blood flow equation

Answer 33

rate of blood flow (ml/min)= volume of blood (ml) / number of minutes

Question 34

how does the structure of an artery relate to its function?

Answer 34

carries blood away from the heart under high pressure - has a small lumen and thick, elasticated walls that can stretch

Question 35

how does the function of a vein relate to its function?

Answer 35

carries blood back away to the heart low pressure - does not need thick elasticated walls, but has valves to prevent blood flow in the wrong way

Question 36

how does the structure of a capillary relate to its function?

Answer 36

carries blood to cells and tissues - has a one-cell-thick wall to provide a short diffusion pathway

Question 37

describe 2 methods of treating coronary heart disease (CHD)

Answer 37

1. statins to reduce cholesterol ~ drugs- reduce the quantity of fatty deposits in arteries 2. stents ~ surgery ~ tubes inserted into arteries and hold them open

Question 38

state advantages and disadvantages of statins

Answer 38

advantages- tablets ~ easy to make, reduce the risk of strokes and CHD and heart attacks disadvantages ~ might forget to take them, side effects like headaches, takes time to work

Question 39

state advantages and disadvantages of stents

Answer 39

advantages ~ quick recovery time from surgery, instant results disadvantages ~ risk of infection or complications from surgery, might get a blood clot near the stent ~ could cause a heart attack

Question 40

explain the difference between communicable and non - communicable diseases

Answer 40

communicable diseases can spread from person to person or between animals and people e.g. measles, malaria non communicable diseases canton spread between people or between animals and people e.g. asthma, coronary heart disease, cancer

Question 41

describe some risk factors that can directly cause a disease

Answer 41

smoking has been proven to directly cause lung disease, cardiovascular disease obesity can directly cause type 2 diabetes drinking too much alcohol and smoking can cause lots of health problems for the unborn baby radiation and certain substances called carcinogens can cause cancer

Question 42

describe the two types of tumour

Answer 42

1. benign ~ tumour grows and stays in one place, usually not cancerous 2. malignant ~ tumour grows and spreads to healthy tissues, parts break off and travel in the blood. the malignant cells then invade healthy tissues where they form secondary tumours. They are cancerous and dangerous

Question 43

describe 6 tissues found in a leaf

Answer 43

1. waxy cutical ~ reduces water loss by evaporation 2. upper epidermis ~ transparent to allow light to get to the palisade cells 3. palisade mesophyll ~ lots of palisade cells to carry out photosynthesis 4. spongey mesophyll ~ air gaps to allow gases to diffuse in and out 5. low epidermis ~ has stomata controlled by guard cells ~ let’s substances in and out of the leaf 6. xylem ~ transports water 7. phloem ~ transports glucose

Question 44

describe phloem tubes

Answer 44

1. long hallow living cells 2. small pores to allow sap to pass through 3. transport goes in both directions

Question 45

describe xylem tubes

Answer 45

1. long hollow dead cells 2. strengthened by lignin 3. no end walls 4. one direction only

Question 46

describe how sugar and water are transported around the plant

Answer 46

water is transported around the plant in transpiration it is transported via the xylem it moves upwards from the roots to the leaves sugar is transported around the plant in translocation it is transported via the phloem sugar moves in both directions

Question 47

name 4 things that transpiration rate is affected by

Answer 47

1. light intensity (high light intensity = high transpiration rate) 2. temperature (high temperature = high transpiration rate 3. air flow (high airflow = high transpiration rate) 4. humidity (high humidity = low transpiration rate)

Question 48

name the equipment used to measure the transpiration rate

Answer 48

potometer

Question 49

name the process that water enters the root hair cell and define it

Answer 49

osmosis ~ movement of water from an area of high water concentration to an area of low water concentration through a partially permeable membrane does not require energy

Question 50

name the process that minerals enters the root hair cell and define it

Answer 50

active transport ~ movement of a substance from an area of low concentration to an area of higher concentration, requires energy