2A-Cell Strucutre and Division

Question 1

what is a eukayotic cell

Answer 1

animal or plant cell that is more complex then a prokayotic cell

Question 2

what is a prokayotic cell

Answer 2

bactieral cell less complex and single stand DNA

Question 3

what does a nucleus contain

Answer 3

nucelar pores
nucelar envelop
nucelous
chromatin

Question 4

what is the role of the nucleus

Answer 4

controls cell activity
dna contains

Question 5

what is the role of the cell surface membrane

Answer 5

regulates the movement of substances into and out of the cells

Question 6

what is the role of the mitrochondrion

Answer 6

the site of aerobic respiration where atp is produced

Question 7

what does the mitochondrion contain

Answer 7

double membrane- inner and outer
cristae
matrix

Question 8

what is the role of the chloroplast

Answer 8

the site of photosynthesis. happens in the grana and stroma

Question 9

what does the chloroplast contain

Answer 9

dohble membrane, also has thylakoid membrane. these membrane stack up to form grana- linked by lamellae

Question 10

what is the role of the golgi apparatus

Answer 10

processes and packages new lipids and proteins

Question 11

what is the role of the golgi vesicles

Answer 11

stores lipids and proteins made by golgi appartus and transports them out of the cell

Question 12

what is the role of the lysosomes

Answer 12

contain hydrolytic enzymes. can be used to break down invading cells

Question 13

what is the role of the ribosomes

Answer 13

site where proteins are made

Question 14

what is the role of the rough endoplasmic reticulum

Answer 14

folds and processes proteins that have been madde at the ribosome

Question 15

what is the role of the smooth endoplasmic reticulum

Answer 15

synthesisies and processes lipids

Question 16

what is the role of the cell wall

Answer 16

supports and prevents them changing shape

Question 17

what is the role of the cell vacuole

Answer 17

helps maintain pressure inside the cell and keep the cell rigid to stop plant wilting

Question 18

what cells can become specialised to carry out a specific function

Answer 18

multicellular eukayotic organisms

Question 19

how are specialised cells organised into tissues organs and organ systems

Answer 19

specialised cells grouped together for tissues
tissies= cells working together to perform a specific function form
different tissues working together form organs
different organs make different organ systems

Question 20

what is the structure of s proksyotic cell

Answer 20

-cytoplasm has no membrane bound organelles
- the flagellum
- circular dna that is free floating
- plasmids are small loops of dna
- some have a capsule that protects the cell
- cell wall supports the celll and prevents from changing
- plasma membrane

Question 21

what are viruses

Answer 21

acellular
nucleic acid surrounded by proteins
smaller then bactiera
- no plasma membrane, no cytoplasm and no ribosomes

Question 22

describe the steps of binary fission

Answer 22

1) circular DNA and plasmids replicates. dna gets replicated oncee and plasmids loads of times
2) cells gets bigger and DNA loopw move to opposite poles
3) cytoplasm begins to divide and new walll begins to form
4) cytoplasm divides and 2 daughter cells are produced

Question 23

how do viruses replicate

Answer 23

1) attachment proteins bind to complimentary receptor proteins on surface of host
2) they then inject their DNA or RNA into the host cell and use that to reproduce

Question 24

what is the magnification equation

Answer 24

mag=size of image/ size of real object

Question 25

how does an optical micrpscope work

Answer 25

uses light to form an image low resolution so cant see membrane bound organelles x1500 mag

Question 26

how do electron microscopes work

Answer 26

uses electrons to form an image higher reolution so give more detail x1,500,000 mag

Question 27

how does a transmission electron microscope work

Answer 27

use lectromagnets to focus a beam of electrons which is then transmitted through specimens denser part absorb more so look darker - good as they can produce high resolution images - only use on thing specimens

Question 28

how does scanning electron microscope work

Answer 28

scan a beam of electrons across the specimen. this knocks off electrons from specimen which gather in tube to form image - image shows surface and is 3d - gives lower resolution them TEMs

Question 29

how do you prepare a microscope slide

Answer 29

-put a drop of water on slide - use tweezers to put small slice of specimen on it - add a drop of stain - finally add the cover slip

Question 30

how does cell fractionation work

Answer 30

1) homogenisation- breaking up cell done by grinding or vibrating cell breaking the plasma membrane then keep cold to reduce enzyme activity, be in isotonic solution and a buffer solution 2) filitration- get rid of big bits 3) ultracentrifugation add sample tube and place in machine spin at lowest speed to get heaviest then drain that. spin on higher speed and the next heaviest will sink and repeat till you have desired

Question 31

what are the 4 phases of the cell cycle

Answer 31

Gap phase 1- cell grows and new organelles and proteins made Synthesis-cell replicates it DNA Gap phase 2- cell keeps growing and proteins needed for cell divsion made Mitosis- cell cycle ends

Question 32

what is interphase

Answer 32

G1,G2 and S phases

Question 33

what is mitosis needed for

Answer 33

growth and repair of tissues

Question 34

what are the 4 phases of mitosis

Answer 34

prophase metaphase anaphase telophase

Question 35

what happens in prophase

Answer 35

the chromosomes condese, getting shorter and fatter. chromosomes are visble and nuclear envelope breaks down

Question 36

what happens in metaphase

Answer 36

the chromosomes line up along middle of cell and become attached to the spindle by their centromere

Question 37

what happens in anaphase

Answer 37

the centromeres divide, seperating each pair of chromatids spindles contract pulling chromatids to opposite poles makes chromatids v shaped

Question 38

what happens in telophase

Answer 38

chromatids reach poles uncoil and become long and thin now called chromosomes nuclear envelope forms around each group of chromomes . division of cytoplasm

Question 39

what is cancer

Answer 39

uncontrollable cell growth

Question 40

how do some cancer treatments work

Answer 40

they target the cell cycle usally the G1 or S phase

Question 41

what is the equation for mitotic index

Answer 41

number of cells with visible chromosomes / total number of cells observed

Question 42

what experiment can be used to see mitosis

Answer 42

root tip squashed and stained put under a microscope

Question 43

how do you control microscope

Answer 43

put slide in select lowest powered objective lens use coarse adjustment knob to bring stage up until its focused focus with fine adjustment knob change mag if need be