Nature of living organism

Question 1

They need nutrition

Answer 1

living organims need nutrients to provide them with energy and the raw materials for growth and repair . Nutrients include things like protens, fats and carbohydrates as well as vitamins and minerals

Question 2

they respire

Answer 2

organisms release energy from their food by a process called respiration

Question 3

they excrete their waste

Answer 3

waste products such as carbon dioxide and urine have to be removed. This is called excretion

Question 4

They respond to their surroundings

Answer 4

they can react to changes in the enviornment

Question 5

they move

Answer 5

organisms move towards things like water and food and away from things like predators and positions

Question 6

homeostasis

Answer 6

they can control they internal conditions, including temp and water content

Question 7

they reproduce

Answer 7

they have to produce offspring in order for their species to survive

Question 8

they grow and develop

Answer 8

they grow and develop into adult form

Question 9

organelles

Answer 9

tiny structures within cells

Question 10

animal cell

Answer 10

nucleas, cell membrane, cytoplasm

Question 11

nucleas

Answer 11

an organelle which contains the genetic material that controls the cells actitvities, it is surrounded by its own membrane

Question 12

cell membrane

Answer 12

this membrane forms the outer surface of the cell and controls the substances that go in and out.

Question 13

cytoplasm

Answer 13

a gel-like substance where most of the cells chemical reactions happen. It contains enzymes which control these reactions.

Question 14

plant cell

Answer 14

nucleas, cell membrane, cytoplasm, large vacuole, cell wall, chloroplasts

Question 15

chloroplasts

Answer 15

photosynthesis occurs here. They contain a green pigment called chlorophyll, which is used in photosynthesis.

Question 16

cell wall

Answer 16

a rigid structre made of cellulose, which surrounds the cell membrane, it supports the cell and strengthens it

Question 17

vacuole

Answer 17

a large organelle that contains cell sap (a weak solution of sugars and salts) it helps to support the cell)

Question 18

tissue

Answer 18

a tissue is a group of similar cells that work together to carry out a particular function.

e.g. plants have a xylem tissue to transport water/minerals and a phloem tissue to transport sucrose and amino acids

a tissue can contain more than one cell type

Question 19

organ

Answer 19

a group of different tissues that work together to perform a function

made up of tissue types

Question 20

systems

Answer 20

organs work together to form organ systems, each system does a different job

Question 21

what is a cell

Answer 21

the smallest structural and functional unit of an organism , cells are specialised

Question 22

diffusion

Answer 22

the net random movement of particles from a high concentration to a low concentration

Question 23

osmosis

Answer 23

the movement of water from a high concentration of water to a low concentration of water through a slelectively permeable membrane.

Question 24

active transport

Answer 24

particles moving against the concentration gradient using energy, from a low concentration to a high concentration.

Question 25

how do substances move in and out of cells

Answer 25

by diffusion, osmosis and active transport

Question 26

diffusion through cells

Answer 26

only small substances such as glucose, amino acids, oxygen and water can

Question 27

if a cell is short of water

Answer 27

the solution inside it will become quite concentrated, meaning the solution outside is more dilute, so water will move into the cell by osmosis.

Question 28

if a cell has lots of water

Answer 28

the solution inside it will become more dilute meaning the water will be drawn out of the cell by osmosis.

Question 29

factors that affect the movement of substances into and out of cells

Answer 29

concentration gradient
temp
surface area to volume ratio

Question 30

concentration gradient

Answer 30

the greater the concentration gradient, the faster the rate of diffusion and osmosis

Question 31

surface area to volume ratio

Answer 31

the larger the surface area, the faster the rate of diffusion and osmosis

Question 32

temperatrue

Answer 32

increasing the temp increase the rate of difusion and osmosis

Question 33

experiment on diffusion in a non living system

Answer 33

1. first make some agar jelly with phenolphthalein and dilute sodium hydroxide, turning it pink.
2. then fill a beaker with some dilute hl, using a scalpel, cut out a few cubes from the jelly and put them into a beaker of acid
3. if you leave the cubes for a while they’ll turn colourless as the acid diffuses into the agar jelly and neutralises the sodium hydroxide

Question 34

experiement for osmois in living system

Answer 34

cut up a potato into identical cylinders, and get some beakers, containing differing sugar solutions.

one should be put water, another should be very concentrated sugar solution. Then you can have a few others with concentrations in between.

You measure the length of the cylinders, then leave a few cylinders in each beaker for half an hour or so. Then you take them out and measure their lengths again

If the cylinders have drawn in water by osmosis, they’ll be a bit longer, if water has been drawn out, theyll have shrunk a bit

Question 35

experiment for osmosis in a non living system

Answer 35

Tie a piece of wire around one end of some visking tubing and put a glass tube in the other end- fix the tubing around it with wire. Then, pour some sugar solution down the glass tube into the risking tubing

Put the risking tubing into a beaker of pure water- measure where the sugar solution comes up to on the glass tube

leave the tubing overnight, then measure where the liquid is in the glass tube. Water should be drawn into the Visking tubing by osmosis and this will force the liquid up the glass tube.