Producing New Cells

Question 1

what does cell division allow a single celled organism to do

Answer 1

reproduce

Question 2

what does cell division allow multicellular organism to do

Answer 2

repair damaged tissues and grow

Question 3

why does your body need stem cells

Answer 3

you body needs specialised cells to grow and repair. Most specialised cells cant make copies of themselves but stem cells can

Question 4

what are stems cells

Answer 4

stem cells are unspecialised cells which have no specific function. They have the ability to develop and differentiate into specialised cells with particular functions.

Question 5

describe tissue stems cells

Answer 5

they are stem cells obtained from the body throughout life - they can only develop into a few types of specialised cells - multipotent

Question 6

describe embryonic stem cells

Answer 6

embroyonic stem cells are obtained from an embryo - they can develope into any type of specialised cell - pluripotent

Question 7

what is the ethical concern of using embryonic stem cells

Answer 7

in order to extract the embryonic stem cell you need to kill the embryo

Question 8

what are some medical uses of stem cells

Answer 8

organ transplants
skin grafts
treat cancer/diabetes

Question 9

multicellular organisms?

Answer 9

made of more than 1 type of cell

Question 10

unicellular organisms

Answer 10

made of only 1 cell e.g amoeba

Question 11

hierarchy in multi-cellular organism

Answer 11

cell–>tissue–>organ–>system

Question 12

why do cells become specialised ?

Answer 12

to perform specific functions

Question 13

what is a specialised cell

Answer 13

a specialised cell is a type of cell which has adapted to perform a specific function.

Question 14

root hair cells (plants)

Answer 14

specialisation
large surface area

function of specialisation
absorbs more water from soil

Question 15

red blood cell

Answer 15

specialisation
contains haemoglobin
no nucleus
biconcave shape

function of specialisation 
carries more oxygen around body.

Question 16

sperm cell (haha like sperm)

Answer 16

specialisation
has a tail

function of specialisation
swim to egg for fertilisation

Question 17

egg cell (haha like ovaries)

Answer 17

specialisation
contains a food source

function of specialisation
provide developing embryo with energy

Question 18

why do unicellular organisms under go cell division

Answer 18

to reproduce to form two new identical cells

Question 19

why do multicellular organisms undergo cell division

Answer 19

mitosis provides new cells for growth and repair of damaged tissues and replacment of dead or damaged cells. It also maintains the diploid chromosome compliment

Question 20

what is a pathogen

Answer 20

any bacteria, virus or microbe which can cause disease

Question 21

what precautions should be taken when dealing with pathogens

Answer 21

aseptic techniques

Question 22

give examples of aseptic technique

Answer 22

all equipment should be sterllised
hands washed before and after
plates used to culture microbes should be sealed and never opened

Question 23

why are aseptic techniques important to the organisms you are trying to grow.

Answer 23

stops contamination of the plates with other microbes which will act as competitors .

Question 24

what factors to cells require to grow in the lab

Answer 24

a suitable nutrient medium
suitable temperature
supply of oxygen
suitable pH

Question 25

what is abotosis

Answer 25

programmed cell suicide

Question 26

what is matastisis

Answer 26

cancer cells spreading from tumor to different part of the body through the blood stream

Question 27

what is cancer

Answer 27

cancer is caused by cells dividing uncontrollably due to genetic code damage. They divide to form a tumor. (abnormal cell growth, fight the power)

Question 28

what does haploid mean?

Answer 28

a cell containing only one set of chromosomes (gametes/sex cells)

Question 29

what does diploid mean?

Answer 29

cells containing two sets of chromosomes (dip like double)

Question 30

what controls cell division

Answer 30

the nucleus - it contains the genetic information/chromosomes and controls cell activity

Question 31

what are the animal and plant gametes

Answer 31

animal
sperm and egg

plant
pollen and ovule

Question 32

humans and guppy fish have the same amount of chromosomes, explain why they are so different

Answer 32

the order of bases in teh DNA that makes up the chromosome are different

Question 33

what is a gene

Answer 33

a section of a chromosome which codes for a protein

Question 34

what is DNA

Answer 34

carries genetic code

Question 35

what is a chromosome

Answer 35

thread like structure containing genetic information

Question 36

what is mitosis

Answer 36

when a mother cell divides to produce two daughter cells with identical diploid chromosome compliments

Question 37

location of mitosis?

Answer 37

nucleus (DNA found there)

Question 38

Mitosis maintains the diploid chromosomes compliment (number of chromosomes) when producing new cells

Answer 38

Mitosis maintains the diploid chromosomes compliment (number of chromosomes) when producing new cells

Question 39

steps of mitosis

Answer 39

step 1) long uncoiled chromosomes not yet individualy visible
chromosomes are replicating
step 2) chromosomes shorten, thicken and replicate to form 2 i i
identical chromatids
chromosomes now visible
nuclear membrane disappears
step 3)chromosomes line up at equator of cell
spindle fibres attach to pairs of chromatids
step 4)pairs of chromatids are pulled apart and chromosomes are
pulled to opposite ends of the cell.
step 5) nuclear membrane reforms and cytoplasm divides.
step 6)two identical diploid cells are produced.

Question 40

what does mitosis provide

Answer 40

new cells for growth and repair of damaged tisses
replacment of dead or damaged cells
it also maintains the diploid chromosome complement in each daughter cell to ensure no genetic information is lost.