biology igcse

Question 1

what are the characteristics of living organisms

Answer 1

MRS GREN
movement
respiration
sensitivity
growth
reproduction
excretion
nutrition

Question 2

what is the chemical equation of cellular respiration

Answer 2

glucose+oxygen —> carbon dioxide + water

Question 3

define movement

Answer 3

the change of place or position caused by an organism

Question 4

define respiration

Answer 4

the chemical reaction in cells that break down to release energy for metabolism

Question 5

define sensitivity

Answer 5

the ability to detect and respond to changed of the environment

Question 6

define growth

Answer 6

the permanent increase in size and dry mass of a living organism

Question 7

define reproduction

Answer 7

the process of making the same kind of organism

Question 8

define excretion

Answer 8

the removal of waste products for metabolic processes

Question 9

define nutrition

Answer 9

taking in materials for energy, growth and development

Question 10

define species

Answer 10

the group of similar living organisms that can breed with one another to produce a fertile

Question 11

what are the two levels of classification in the binomial system

Answer 11

genus + species

Question 12

A student defined respiration as being the same as breathing. Are they correct? Provide a reason to support your answer.

Answer 12

Breathing and respiration are two completely different things but interrelated body processes that assist body organs to function properly 

Question 13

Humans breathe but bacteria do not. Is it correct to state that bacteria are alive? What makes you think that?

Answer 13

Bacteria is not considered a living organism as it does not share all the characteristics of living organisms

Question 14

What is the energy released in cellular respiration used for?

Answer 14

You need energy to grow, move around, to excrete  cell division

Question 15

Why is it important to say that energy is released, not produced.

Answer 15

As energy cannot be created nor destroyed, only transferred 

Question 16

Why does an increase in the number of cells cause growth?

Answer 16

the increase in the number of cells increase the volume and size of an organism

Question 17

Why does the amount of dry mass in an organism cause growth?

Answer 17

Dry mass is made up of organic molecules when there is more organic molecules, the dry mass increases 

Question 18

what are the two types of reproduction

Answer 18

sexual and asexual

Question 19

How do the two forms of reproduction differ from each other?

Answer 19

Sexual is where offsprings are a result of 2 different gametes fusing together. 

Asexual is where offspring are from the same parent 

Question 20

What is metabolism?

Answer 20

Metabolism is the term used for chemical reactions that go on inside an organism’s body. 

Question 21

How is metabolism linked to excretion?

Answer 21

Metabolic processes toxic products and it is removed from the body through excretion. 

Question 22

This image shows a cow producing faeces. Is this an example of excretion? What makes you think that?

Answer 22

No, as faeces is not excretion, it is undigested food, Excretion as the removal of the waste products of metabolism and substances in excess of requirements. 

Question 23

What is the purpose of nutrition?

Answer 23

To give the substances as it needs to release energy 

Question 24

What is the difference between a nutrient and nutrition?

Answer 24

Nutrient is a substance you consume and nutrition is the process of taking in and using those substances. 

Question 25

How do plants obtain their nutrients?

Answer 25

Photosynthesis

Question 26

How do animals obtain their nutrients?

Answer 26

Consumption of organic matter

Question 27

what are they three ways that a plant cells differs to animal cell

Answer 27

• cell wall
  -permanent vacuole
• chloroplast

Question 28

what is the function of a nucleus

Answer 28

contains DNA and controls the activity of the cell

Question 29

what is the function of a mitochondrion

Answer 29

carries out respiration

Question 29

what is the function of a ribosome

Answer 29

to make protein

Question 29

what is the function of a cell membrane

Answer 29

controls the movement of the cell of what goes in and out

Question 30

what is the function of a cytoplasm

Answer 30

biochemical reactions occur here

Question 30

what is the function of a vacuole

Answer 30

it contains water and ions

Question 31

what is the function of a root hair cell and explain

Answer 31

to absorb water and inorganic nutrients
- the long extensions increase the surface area of the cell enabling it to absorb water and nutrients more efficiently

Question 32

what is the function of a ciliated cell and explain

Answer 32

the movement of mucus int he trachea and bronchi
- moving mucus
- hair like projection

Question 33

what is the function of a palisade mesophyll cell and explain

Answer 33

carries out photosynthesis
- lots of mitochondria and a large surface area to maximise the absorption of light

Question 34

what is the function of a red blood cell and explain

Answer 34

to transport oxygen
- contains haemoglobin to bind with oxygen
- no nucleus for more space

Question 35

what is the function of a sperm cell and explain

Answer 35

reproduction
- tails to swim
- lots of mitochondria
- has enzymes in the acrosome

Question 36

what is the function of a ovum and explain

Answer 36

reproduction
- large cytoplasm with yolk as energy store
- outer layer prevents more than one sperm entering
- fuses witha sperm to form a zygote