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Biology GCSE > Cells > Flashcards

Flashcards in Cells Deck (39):
1

Describe a nerve cell

Carry electrical impulses around the body
communication between brain and rest of the body
Axons carry nerve impulses from one place to another.
Pass through synapses and electrical impulse turns into chemicals with mitochondria to provide as energy.

2

Example of specialised animal cells

Sperm cells, nerve cells, muscle cells

3

Describe a sperm cell

Contains genetic information from the male
Breaks into the egg to fertilise
Tail helps it swim
Middle section full of mitochondria which makes the tail move
Nucleus contains genetic information.

4

Describe a muscle cell

Contract and relax
Moves bones of skeleton
Contain special protein which makes fibres contract
mitochondria transfer the energy
Store glucose used for respiration

5

Describe a root hair cell

Cells on the surface of plant roots that stick out of the soil
Gives plant bigger surface area for absorbing water and mineral ions from the soil
Mitochondria transfers energy for active transport

6

Sperm Cells are specialised for...

reproduction

7

Nerve cells are specialised for...

rapid signalling

8

Muscle cells are specialised for..

contraction

9

Root hair cells are specialised for...

absorbing water and minerals

10

What is a Specialised Cells

As cells change, they develop different subcelular structures and turn into different types of cells which carry out specific functions

11

Describe a phloem cell

Carries food by photosynthesis around the plant
Formed in plates which carries dissolved food
Supported by other cells

12

Phloem and xylem cells are specialised for...

transporting substances

13

Example of specialised plant cells

root hair cells, phloem and xylem cells

14

Describe a xylem cell

Transports water and minerals from root to highest level of leaves
Builds in spirals
Strong

15

Describe a Eukaryotic Cell

Has a cell membrane, cytoplasm, genetic material
Plant and animal cells are eukaryotic cells

16

Describe a Prokaryotic Cell

Single-celled organisms like bacteria
Bacteria have cytoplasm and a cell membrane but doesn’t contain cellulose
May contain extra small rings of DNA called plasmids which are antibiotic resistant

17

Average animal cell size

10-30 micrometers

18

Average plant cell size

10-100 micrometres

19

Describe a Light microscope

cheap, can only magnify around 2000 times, can magnify live specimen

20

Describe an electron microscope

expensive, can magnify to 2,000,000 times, 3D, have to be kept in special temperature, pressure humidity.

21

Explanation of diffusion

Diffusion is spreading out of particles of gas or any substance in a solution.
Net movement from high concentration to low
greater difference in concentration quicker diffusion happens
Higher temperature faster diffusion happens

22

Explanation of diffusion in living organisms

Dissolved substances more in and out of a cell through a cell membrane
Glucose, gases, oxygen
Oxygen for respiration passes from lungs into red blood cells, through the cell membranes by diffusion.

23

How Osmosis is different from Diffusion?

Osmosis is the special type of diffusion - only for water.

24

Explanation of osmosis

Osmosis is the diffusion of water molecules from a dilute solution (high water concentration/ higher water potential) to a concentrated solution (low water concentration/potential) through a partially permeable membrane (e.g. a cell membrane)

25

What makes a solution?

solvent+solute

26

What makes a solution more or less concentrated?

concentrated solution = more solute
dilute solution = less solute

27

Osmosis in Plant cells

Dilute solution inside the cell
More concentrated solution outside the cell
The water leaves the cell so it shrivels up
The cell membrane pulls away from the cell wall and the Vacuole gets smaller.
Dilute solution inside the cell
Pure water outside the cell
Water enters the cell
The cell bulges slightly and the vacuole gets bigger.
The cell wall prevents the cell from bursting

28

Osmosis in animal cells

Dilute solution inside cell
Concentrated solution outside cell
Water leaves cell
Cell shrivels/crenated
Dilute solution inside cell
Pure water outside cell
Water enters the cell
Cell bursts (lysis) because there is no cell wall

29

Description of active transport

Protein molecules, called carriers, carry particles across the membrane by respiration
the cell, via respiration.

30

Description of Photosynthetic Cells

Makes food by photosynthesis
Contain chloroplasts In layers
Permanent vacuole

31

Description of a Cell wall

strengthens the cell membrane (only in plants)

32

Description of Chloroplasts

make food by photosynthesis (only in plants)

33

Description of a Vacuole

filled with cell sap to keep the cell rigid (only in plants)

34

Description of a nucleus

controls activity of cell, contains genes, contains instruction for making new cells

35

Description of cytoplasm

Liquid gel which the organelles are in, where chemical reactions happen.

36

Description of a cell membrane

controls what comes in and out of the cell

37

Description of mitochondria

where aerobic respiration takes place

38

Description of ribosomes

where protein synthesis takes place

39

Magnification equation

Image Size = actual size x magnification