Chapter 1- Cell Structure and Transport

Question 1

Mitochondria-

Answer 1

Most energy is released by respiration here

Question 2

Ribosomes-

Answer 2

Protein synthesis happens here

Question 3

Permanent vacuole-

Answer 3

Filled with sap to keep the cell turgid

Question 4

Animal and plant cells both have…

Answer 4

Nucleus, cytoplasm, cell membrane

Question 5

ONLY plant cells have…

Answer 5

Chloroplast, cell wall, vacuole

Question 6

Bacterium cell-

Answer 6

Has only one cell (no proper nucleus), there is a singular strand of DNA called plasmids, and they don’t have chloroplasts or mitochondria. it is prokaryotic

Question 7

Yeast is…

Answer 7

A single called organism and have a nucleus

Question 8

what is a prokaryotic cell?

Answer 8

a singular celled organism

Question 9

what is special about electron microscopes?

Answer 9

they can magnify better, and have a better resolution (sharper)

Question 10

what is the equation to calculate magnification?

Answer 10

image size/ real size

Question 11

how do you get from µm to mm?

Answer 11

divide by 1,000

Question 12

what is 240000000 in standard form?

Answer 12

2.4 x10^8

Question 13

how do you prepare a slide?

Answer 13

1) add a drop of water
2) cut up an onion and put it on the slide, spreading it thin to be able to see all the layers
3) add a drop of iodine solution because then it is easier to see
4) place a cover slip, to protect, no air bubbles!

Question 14

what is cell differentiation?

Answer 14

when is cell is specialised to do it’s job more effectiveley.

Question 15

what are animal cells called that can differentiate?

Answer 15

stem cells, and in embryos, bone marrow and liver

Question 16

how have sperm cells differentiated?

Answer 16

it has a long tail and rounded head to help it swim, as it is more streamlined, lots of mitochondria so there is lots of energy.

Question 17

how are nerves cells specialised?

Answer 17

they are long, so they can have long connections, and carry signals further and faster

Question 18

how are muscle cells differentiated?

Answer 18

the muscle calls can contract quickly and have lots of mitochondria to generate the energy needed to contract quickly

Question 19

how are root hair cells specialised?

Answer 19

by being very long so they can effectively and quickly absorb minerals, as well as having a large surface area.

Question 20

xylem are…

Answer 20

hollow

Question 21

phloem have…

Answer 21

very few sub-cellular structures to allow food to flow through easily.

Question 22

what is the way in which stem cells can have the same genetic info. as the patient?

Answer 22

Therapeutic cloning

Question 23

what are the stem cells in plants?

Answer 23

meri-stem cells

Question 24

how many pairs of chromosomes are there in each nucleus?

Answer 24

23 pairs

Question 25

what is mitosis?

Answer 25

the stage of the cell cycle where the cell divides

Question 26

90% of time in cell cycle is…

Answer 26

growth and DNA repication. when the cell is not dividing, then the DNA is out in long strips and then stretches when it is about to divide and then splits into 2.

Question 27

10% of time in cell cycle is…

Answer 27

mitosis, to grow and replicate cells. the dividing is when the chromosones go to each ennd of the cell, and the nucleus splits into 2, and they all have the DNA

Question 28

what is binary fission?

Answer 28

when a cell splits into 2, the circular DNA and plasmid replicate, and the cell then gets bigger, and the DNA splits and goes to opposite ‘poles’ of the cell. the new cell walls then begin to develop, an then the cell splits into two daughter cells and eaach has a fair share of things from the parent cell.

Question 29

why would people choose to clone with meri-stem cells?

Answer 29

they are a quick and cheap method to make identical copies and they can be modified against some diseases they are prone to

Question 30

what is culturing microorganisms?

Answer 30

where bacteria is grown in an environment which contains carbs, minerals, proteins and vitamins

Question 31

why do you use uncontaminated cultures?

Answer 31

so you kill all unwanted microorganisms, store upside down, stop condensation

Question 32

how do you do the experiment of seeing what effect the antibiotics have?

Answer 32

place paper discs in different concentrations of antibiotics and put in thee agar plate/petri dish. the bigger the clear the circle, the more effective the antibiotic

Question 33

how do you work out the area of each of the inhibition zone?

Answer 33

measure the radius of each circle, and then use the equation, πr ²

Question 34

what is diffusion?

Answer 34

it is the gradual movement of particles from a place of high concentration, to low concentration, for example the spreading of deodorant through an area

Question 35

how can cell membranes be linked too diffusion?

Answer 35

they hold the cell together, but they also let very small molecules diffuse through, such as oxygen (respiration) and amino acids and glucose and water. although big molecules such as starch and proteins cannot fit as they are too large

Question 36

what is osmosis?

Answer 36

the movement of water molecules from a place of high concentration to low concentration, through a partially-permeable membrane

Question 37

what is a practical for osmosis?

Answer 37

cut up 2 potato cylinders, and put them in beakers of firstly pure water and then concentrated sugar solutions, and weigh them afterwards to see if they have absorbed the liquids; the more absorbed the better the osmosis rates

Question 38

what is active transport?

Answer 38

the substances being absorbed against the concentration gradient, ie the opposite of osmosis or diffusion and it can happen in the gut to absorb glucose

Question 39

how quickly a substance gets absorbed depends on the…

Answer 39

… surface area to volume ratio

Question 40

what have the villi done to adapt?

Answer 40

they have a really large surface area so more digested food can be absorbed quicker in the blood