b1 - cells

Question 1

what does the mitochondria do

Answer 1

respiration and provides energy

Question 2

how big are plant and animal cells

Answer 2

10-100micrometres across

Question 3

what do plant cells contain that animal cells don’t

Answer 3

chloroplast, permanent vacuole, cell wall

Question 4

what type of cells are plant and animal cells

Answer 4

eukaryotic

Question 5

what type of cell are bacterial cells

Answer 5

prokaryotic

Question 6

what do prokaryotic cells not have

Answer 6

nucleus

Question 7

how are muscle cells adapted to contract

Answer 7

long tubes, lots of mitochondria for energy

Question 8

how are nerve cells specialised to send impulses

Answer 8

long so they can carry the impulses around the body, end in branches that connect with other cells

Question 9

how are sperm cells specialised

Answer 9

long and flexible tail for swimming, large number of mitochondria in middle for energy, head carries enzymes which helps sperm break through the eggs cell membrane

Question 10

how are root hair cells adapted

Answer 10

long and thin for a larger surface area so it’s easier to absorb nutrients and water

Question 11

what is differentiation

Answer 11

the process of turning into a specialised cell

Question 12

when do animal cells differentiate

Answer 12

at an early stage of their development, can continue in mature animals but only for replacement and repair

Question 13

can plants differentiate and for how long

Answer 13

yes, they don’t lose their ability to differentiate ever

Question 14

what are stem cells

Answer 14

undifferentiated cells and can turn into one of many specialised types of cell

Question 15

what can animal stem cells be

Answer 15

adult or embryonic

Question 16

what are embryonic stem cells

Answer 16

undifferentiated cells that are taken after an egg has been fertilised

Question 17

what is therapeutic cloning

Answer 17

creating an embryo with the same genes as a patient

Question 18

what are the concerns of using stem cells in medicine

Answer 18

viruses can infect stem cells, oppose ethical or religious grounds

Question 19

where are undifferentiated stem cells in plants found

Answer 19

in the meristem tissue

Question 20

how do light microscopes work

Answer 20

use lenses to focus light and create a magnified image of a sample

Question 21

what is the formula for magnification

Answer 21

image size divided by real size

Question 22

when were electron microscopes first used

Answer 22

1930s

Question 23

how do electron microscopes work

Answer 23

use a beam of electrons passing through the sample

Question 24

why are electron microscopes better than light microscopes

Answer 24

have a higher resolution and magnification

Question 25

what do chromosomes carry and where are they found

Answer 25

genetic info, found in nucleus

Question 26

what is cell division

Answer 26

creating new cells to allow the organism to grow or be repaired

Question 27

what happens in stage one of cell division

Answer 27

number of cell components increase

Question 28

what happens in stage 2 of cell division

Answer 28

chromosomes replicate

Question 29

what happens in stage 3 of cell division

Answer 29

cell divides in 2, known as mitosis

Question 30

how does mitosis work

Answer 30

two sets of chromosomes are pulled to opposite ends of the cell, then nucleus divides in two, then the cell membranes and cytoplasm divides making two identical cells

Question 31

what is diffusion

Answer 31

particles in liquids and gases move from areas with higher concentration to areas with lower concentration

Question 32

how does diffusion happen in the lungs

Answer 32

during gas exchange, through alveoli to the capillaries, oxygen goes into the blood and carbon dioxide goes into the alveoli and is breathed out

Question 33

what is urea

Answer 33

waste product produced by body cells

Question 34

what is the diffusion rate affected by

Answer 34

concentration gradient, temperature (happens faster at higher temp), surface area

Question 35

how is the small intestine adapted to absorb nutrients

Answer 35

villi for larger surface area

Question 36

what is osmosis

Answer 36

water diffuses through a partially permeable membrane

Question 37

what is active transport and what does it require

Answer 37

substances move from areas of low concentration to areas of high concentration, requires lots of energy