bio test sutt 2

Question 1

put these in order from biggest to smallest gene cell nucleus chromosome

Answer 1

cell nucleus chromosome gene

Question 2

how many chromosomes are found in most human cells

Answer 2

46(23 pairs)

Question 3

the human chromosome number 15 contains a gene involved in determining eye colour.How many chromosome 15s would you expect to find in the nucleus of the following : the retina
the muscle cell
sperm cell

Answer 3

2
2
1

Question 4

name 2 factors that play a role in characteristics of a plant

Answer 4

environment and genes

Question 5

what is the chemical which genes and chromosomes are made of

Answer 5

DNA

Question 6

explain how the sex of a human is determined by chromosomes

Answer 6

two X chromosomes=girl
1 X and 1Y chromosoe=boy

Question 7

what does DNA stand for

Answer 7

deoxyribonucleic acid

Question 8

explain how identical twins are made

Answer 8

a sperm fertilises an egg and the zygote begins to dive into many cells later the embryo splits into 2 separate groups of cells

Question 9

explain how non identical twins are made

Answer 9

2 eggs get released and 2 sperm fertilise the eggs and the 2 babies develop separately

Question 10

do identical twins share the same dna

Answer 10

yes

Question 11

why do some identical twins look different

Answer 11

because genes are not the only thing that effect looks environmental and different lifestyles also play a part

Question 12

what is dna broken into large numbers of

Answer 12

genes

Question 13

what is a allele

Answer 13

a different form of the same gene e.g brown eyes and green eyes

Question 14

what is haploid and diploid

Answer 14

Haploid means a cell has one set of unpaired chromosomes, while diploid means a cell has two sets of paired chromosomes(e.g haploid is sperm with 23 chromosomes diploid skin cell with 46 )

Question 15

list 4 reasons why we need mitosis

Answer 15

sometimes for asexual reproduction
growth
repair
replacement of worn out cells

Question 16

list all the phases of mitosis in order

Answer 16

prophase metaphase anaphase telophase

Question 17

what is is the process that is part of cell division but not mitosis

Answer 17

cytokenisis

Question 18

what is the first stage of the cell cycle

Answer 18

cell growth

Question 19

what happends in the first phase of the cell cycle

Answer 19

cell grows,produces new organelles and essential protiens

Question 20

what is the second phase in the cell cycle

Answer 20

dna replication

Question 21

what happends during the second phase of the cell cycle and why is it needed

Answer 21

DNA is coppied so that each new cell formed during division has a full and identical set of genetic information.

Question 22

what is the 3rd stage of the cell cycle

Answer 22

further cell growth

Question 23

what is the 4th stage of the cell cycle

Answer 23

cell divsion

Question 24

what happends in the 4th stage of the cell cycle

Answer 24

the cell divides its nucleus and cytoplasm

Question 25

what is the cell cycle

Answer 25

the repeating series of stages that a cell goes through to grow ,replicate its DNA and divide to form new cells

Question 26

what happends during prophase

Answer 26

nuclear membran breaks down

Question 27

what happends during metaphase

Answer 27

chromosomes line up in the middle (equator)

Question 28

what happends during anaphase

Answer 28

one copy of each chromosome is pulled to opposite ends

Question 29

what happends during telophase

Answer 29

nuclear membranes reform around each set of chromosomes creating 2 nuclie

Question 30

what is cytokenesis the process of

Answer 30

the processwhen the cytoplasm and cell memrane divide to form 2 identical cells

Question 31

define mitosis

Answer 31

the division of a cells nucleus to produce two genetically identical daughter nuclei

Question 32

how do u calauctae how long each stage of the cell cycle takes

Answer 32

time spent in stage =no. of cells in that stage / total no.of cells x total time of cycle

Question 33

state 3 reasons why organisms need to produce new cells

Answer 33

grlwth ,repair dead /damaged cells,replace dead cells

Question 34

name 2 organaells made during growth phase

Answer 34

mitochondria and ribosomes

Question 35

what is the letter used to represet growth phase 1 dna replication growth phase 2 cell division

Answer 35

G1 S G2 M

Question 36

Explain why cells need to copy dna before they divide

Answer 36

so that each new cell formed during division has a full and identical set of genetic information.

Question 37

during G1 a fox cell has 34 chromosomes after cell divison how many chromosomes will each cell have

Answer 37

34 chromosomes

Question 38

a scientist calculates that a cell cylce lasted 2 hrs if cell divison lasted for 18% of the cycle ,how long did cell division take

Answer 38

21 min and 36 senconds

Question 39

for the same cycle (lasted 2 hrs) the cell spent 33 min replicating dna what %is this

Answer 39

27.5%

Question 40

state 2 things that happen during G1 and G2

Answer 40

G1-> the cell grows in sieze -> organelles are produced G2-> the cell checks and repairs DNA for errors ->protiens needed for mitosis are made

Question 41

what stage of mitosis is ... the cell ready for the first stage of mitosis

Answer 41

prophase

Question 42

what stage of mitosis is ... one copy of each chromosome is pulled to each end of the cell

Answer 42

anaphase

Question 43

what stage of mitosis is ... chromosomes line up in the middle (equator)

Answer 43

metaphase

Question 44

what stage of mitosis is ... nuclear membranes reform around each set of chromosomes

Answer 44

telophase

Question 45

what stage of mitosis is ... cytoplasm and cell membrane divide to form 2 identical cells

Answer 45

cytokensis (NOT PART OF MITOSIS)

Question 46

what stage of mitosis is ... nuclear mebrane breaks down

Answer 46

prophase

Question 47

why does mitosis only occour in certain types of cells

Answer 47

Mitosis only occurs in cells that need to divide — not all cells in the body divide. Reasons: Specialised cells don’t divide Some cells, like nerve cells or muscle cells, are fully specialised and cannot divide. Their job is to function, not reproduce.. Energy efficiency Dividing cells uses lots of energy. The body only divides cells where necessary.

Question 48

what types of cells does mitosis occour in

Answer 48

unspecialised cells

Question 49

in what region are stem cells found in plants

Answer 49

meristems

Question 50

where are meristems found in a plant

Answer 50

shoots and roots

Question 51

are stem cells in plant multi or toti polent

Answer 51

totipotent

Question 52

t or f stem cells in plants can produce a;; types of plant cells anytime during the life of the plant

Answer 52

TRUE

Question 53

name 3 places adult stem cells can be found in the body

Answer 53

bone marrow,skin,blood

Question 54

what type of cells from your bone marrow can they differentiate into

Answer 54

red blood cells white blood cells platelets

Question 55

why cant specialised cells divide

Answer 55

they are permantley differentiated and stop going through mitosis

Question 56

how are plant stem cells different from human stem cells

Answer 56

plant stem cells are found in only meristems but human stem cells are found in a few locations

Question 57

what is a issue with organ donations

Answer 57

rejection

Question 58

why does rejection occour in organ donations

Answer 58

when the humans immune system attacks the donated organ as it recoginises it as a threat

Question 59

name 2 things we can do to fight of rejectiom

Answer 59

drugs can be given tissue typing -organs are matched to the compatiable patient

Question 60

reminder to also go over statement and practice papers

Question 61

what is theraputic cloning

Answer 61

creating patient specific embryonic stem cells to treat diseases or repair damaged tissues

Question 62

give 2 advantages of adult stem cells

Answer 62

can give concent donor not permently harmed

Question 63

give 2 negatives of using adult stem cells

Answer 63

cannot differentiate into all cell types only found in some tissues an not in great numbers

Question 64

give 2 advantages of using embryonic stem cells

Answer 64

can treat a range of diseases can diff3rentiate into all cell types

Question 65

give 2 negatives of using embryonic stem cells

Answer 65

poteintal life can be killed not tested or reliable

Question 66

name 2 diseases stem cells can cure

Answer 66

blindness deafness

Question 67

T or F are all stem cells totipotent

Answer 67

FALSE

Question 68

what are stem cells

Answer 68

are undifferentiated cells that can divide repeatedly and specialise into different types of cells.

Question 69

what is differentiation

Answer 69

when a cell becomes specilised to carry out a role

Question 70

why is it importent for cells to specilise

Answer 70

this makes the cell more efficent at carrying out its role

Question 71

name different ways in which cells can differentiate

Answer 71

change shape of cell change contents change number of particular organelles

Question 72

what is a organelle

Answer 72

a small structure in a cell that has a specific job or function

Question 73

whats the differnce between toti and multipotent cells

Answer 73

totipotent cells can diffrntiate into all types of cells whereas multipotient cells can differentate into a certian range of cell types

Question 74

where are totiptent and multipotent cells found

Answer 74

totipoten cells are found in embryos multipotent cells are found in human adults

Question 75

define diffusion

Answer 75

the movement of particles from an area of hig concentration to an area of low concentration

Question 76

what factors effect the rate of diffususuion

Answer 76

tempurature concentration gradient diffusion distance surface area

Question 77

how does tempurature effect diffusion

Answer 77

the higher the tempurature means the faster the rate of diffusion as particles have more kenetic energy so move faster

Question 78

how does concentration gradient effect diffusion

Answer 78

the steeper gradient(difference in concentration)the fatser the rate of diffusion

Question 79

how does d suface area effect diffusiom

Answer 79

increasing the surface area increases the rate of diffusion

Question 80

how does diffusion distance effect the rate of diffusuion

Answer 80

as the distance molecules need to diffuse decreases rate of diffusion increases

Question 81

in which states does diffusion occour in and why

Answer 81

liquids and gases because their particles can move freely

Question 82

does diffusion move down or up a concentration gradient

Answer 82

down

Question 83

T or F diffusion requires energy

Answer 83

FALSE

Question 84

what is the movement of particles from a area of low concentration to an area of high concentration

Answer 84

active transport

Question 85

list 3 differences between diffusion and active transport

Answer 85

active transport requres energy active ransport moves up a concentration gradient active transport uses carrier protiens

Question 86

give 2 examples of active transport

Answer 86

uptake of gluscose and amino acids in the small intestine absorption of mineral ions by plant roots

Question 87

describe the first part of active transport

Answer 87

the molecule to be transported arrives at the carrier protien

Question 88

describe the second part of active transport

Answer 88

the molecule to be transported combined with the carrier protien energy is supplied to the carrier protien(from an ATP molecule)

Question 89

describe the third part of active transport

Answer 89

the energy is used to make the carrier protien change shape

Question 90

describe the fourth part of active transport

Answer 90

the molecule to be transported is released onto the other side of the membrne .the carrier protien will return to its original shape

Question 91

diffusion or active transport oxygen molecules move into red blood cells using this process

Answer 91

diffusion