3A: Cells

Question 1

What organelles are in a animal cell/eukaryotic cell? (12)

Answer 1

• nucleus
• nucleolus
• nuclear envelope
• rough endoplasmic reticulum
• smooth endoplasmic reticulum
• golgi apparatus
• cytoplasm
• mitochondrian
• ribosome
• lysosome
• cell surface membrane (plasma)
• centriole

Question 2

what is the nucleus

Answer 2

a large organelle surrounded by a nuclear envelope and contains chromatin and a nucleolus

Question 3

what is the function of the nucleus (and the DNA, the nuclear envelope and the nucleolus)

Answer 3

• controls the cells activities
• DNA from the chromatin contains instructions on how to make proteins
• the pores within the nucleus envelope allow substance to move between the nucleus and the cytoplasm
• the nucleolus makes ribosomes

Question 4

what is a lysosome

Answer 4

a round organelle surrounded by a membrane

Question 5

what is the function of a lysosome

Answer 5

the lysosome contains digestive enzymes which can be used to digest invading cells or break down worn out components of the cell
- these enzymes are kept separate from the cytoplasm by the membrane surrounding the lysosome

Question 6

what is a ribosome

Answer 6

a small organelle made up of proteins and RNA
- it can be found either free in the membrane or attached to RER

Question 7

what is the function of a ribosome

Answer 7

to make proteins

Question 8

what is the rough endoplasmic reticulum (RER)

Answer 8

a system of membranes enclosing a fluid filled space - its surface is covered in ribosomes

Question 9

what is the function of rough endoplasmic reticulum

Answer 9

it folds and processes proteins that have been made (translateda) at the ribosomes

Question 10

what is smooth endoplasmic reticulum

Answer 10

a system of membranes enclosing a fluid filled space - has no ribosomes

Question 11

what is the function of smooth endoplasmic reticulum

Answer 11

synthesises and processes lipids

Question 12

what is golgi apparatus

Answer 12

a group of fluid filled, membrane bound, flattened sacs - vesicles are often seen at the edges of sacs

Question 13

what is the function of golgi apparatus

Answer 13

it processes and packages new lipids and proteins - it also makes lysosomes

Question 14

what are mitohondrian

Answer 14

oval shaped - has a double membrane ( inner membrane folded to form a cristae), has a matrix inside which includes enzymes ( used for respiration)

Question 15

what is the function of mitochondrian

Answer 15

it is the site of aerobic respiration - it is where energy (ATP) is produced and provided for respiration

Question 16

what is the centriole

Answer 16

small hollow cylinders made up of microtubes

Question 17

what is the function of the centriole

Answer 17

involved in the separation of chromosomes during cell division

Question 18

what are the oragnelles within a prokaryotic cell

Answer 18

• cell membrane
• circular (chromosonal) DNA
• plasmid DNA
• flagellum
• cytoplasm
• mesosome
• ribosome
• capsule
• pili
• murein cell wall

Question 19

what is a mesosome

Answer 19

inward folds of plasma membrane

Question 20

what is the cell capsule

Answer 20

secreted slime that surrounds the cell

Question 21

what is the role of the cell capsule

Answer 21

helps to protect bacteria from attacks by cells of the immune system

Question 22

what is pili

Answer 22

short hair-like structures attached to the cell

Question 23

what is the role/function of pili

Answer 23

helps prokaryotes stick to other cells
- can be used to aid transfer of genetic material between cells

Question 24

how does bacteria reproduce

Answer 24

asexually through binary fission

Question 25

what is the process of binary fission

Answer 25

- genetic material of cell is replicated - cell grows larger and each set of GM begins to move to opposite ends of the cell - cell wall and cell membrane begin to divide to separate two sets of DNA - cell wall and cell membrane close around each DNA set - cell splits to form 2 identical cells

Question 26

what are the main pieces of a microscope

Answer 26

eyepiece lens objective lens stage stage clips lamp fine dial course dial base

Question 27

what are the two types of microscopes

Answer 27

electron microscope and light microscope

Question 28

key features of a light microscope

Answer 28

- can use living samples - can view in colour - cheap and accessible

Question 29

key features of an electron microscope

Answer 29

- B&W only - samples must be dead - higher resolution and magnifiction than light microscope - expensive

Question 30

what are the two types of electron microscopes

Answer 30

Transmission electron microscopes (TEM) and Scanning Electron microscope (SEM)

Question 31

what are Transmission electron microscopes and when were they discovered

Answer 31

discovered in 1931 - use beams of elctrons - magnification up tp 50,000,000 - produce 2D images - expensive

Question 32

what are Transmission electron microscopes and when were they discovered

Answer 32

discovered in 1931 - use beams of elctrons - magnification up tp 50,000,000 - produce 2D images - expensive

Question 33

what are scanning electron microscopes and when were they discovered

Answer 33

discovered in 1965 - uses electron beams - magnification up to 1,000,000 - produce £D images

Question 34

how to calculate magnification

Answer 34

size of image / size of real image

Question 35

what is the body organisaton system

Answer 35

cells, tssues, organs, organ systems, organisms

Question 36

what are tissues

Answer 36

groups of similar cells that all develop from the same kind of cell

Question 37

what are the 4 main types of tissue

Answer 37

epitheilal tissue muscle tissue connective tissue nervous tissue

Question 38

what is epithelial tissue

Answer 38

lines internal and external surfaces

Question 39

what is muscle tissue

Answer 39

shorten or contract to produce movement

Question 40

what is mitosis

Answer 40

cell division that produces two genetically identical cells

Question 41

what are the three functions of mitosis

Answer 41

growth repair asexual reproduction

Question 42

what are the phases of mitosis

Answer 42

prophase metaphase anaphase telophase

Question 42

what are the phases of mitosis

Answer 42

prophase metaphase anaphase telophase

Question 43

what is the cell cycle

Answer 43

interphase, mitosis, cytokinesis

Question 44

what happens during interphase

Answer 44

te cell prepares for division - DNA unravels and is replicated - organelles are replicated - ATP content increases - cell swells

Question 45

what happens during prophase

Answer 45

chromosomes condense and becoming shorter and fatter - making them visible - centrioles move to opposite poles of the cell - network of protein fibres called the spindle develop - nuclear envelope breaks down and chromosomes are free in cyto

Question 46

what happens during metaphase

Answer 46

- spindle fibre attach to ccehromatids at the centromere - chromatids line up at the middle of the cell

Question 47

what happens during anaphase

Answer 47

-- centromere divides hence separating the sister chromatids - SF contract pulling chromatids to opposite poles - uses energy provided from aerobic respiration in the mito

Question 48

what happens during telophase

Answer 48

- chromatids uncoil and become long & thin (now chromosomes) - nuclear envelope forms around each chromosome - cytoplasm divides to form 2 daughter cells