uplearn

Question 1

difference between mitosis and meiosis

Answer 1

mitosis is one divison and meiosis is 2 division
mitosis produce 2 genetically identical daughter cell whereas meiosis produces 4 genetically different cells.
mitosis contains the same number of chromosome as parent cell whereas meiosis only contains half the chromosome.
mitosis are diploid and meiosis are haploid

Question 2

meiosis involves in how many divisons

Answer 2

2

Question 3

how does meiosis involve in 2 divisions

Answer 3

in the first generation, chromosome that carry the same gene pair up (homologous chromosome), These then separate into 2 chromosome

in the next division, chromosome move apart from each other to form a new pair of daughter cell

Question 4

when does mitosis and meiosis occur after

Answer 4

they occur after interphase

Question 5

what do meiosis result in

Answer 5

genetic variation by producing different combination of gamete allelss

Question 6

genetic variation

Question 7

crossing over

Answer 7

during meiosis 1.
homologous chromosome are close to each other for the chromatid of each pair to twist around each other, spliced and rejoin to the other. This can result in new allele combination

Question 8

independent assortment

Answer 8

homologous pair line up random. This randomises the chromosomes end up in each daughter cell

Question 9

habitat

Answer 9

place where an organism lives

Question 10

community

Answer 10

population of different organisms in a habitat

Question 11

species richness

Answer 11

number of species in a community

Question 12

index of diversity

Answer 12

N(N-1) / sum of n(n-1)
N = total number of organisms in the community
n = total number of organisms in a particular species

Question 13

gene pool

Answer 13

all the alleles in the population

Question 14

allele frequency

Answer 14

probability of an allele appearing in the gene pool

Question 15

hetrozygous

Answer 15

Ff

Question 16

homozygous can be either

Answer 16

Homozygous dominant - FF
Homozygous recessive - ff

Question 17

the frequency of dominant and recessive homozygous would always be

Answer 17

homozygous dominant + homozygous recessive = 1

Question 18

hardy weinberg equation

Answer 18

p squared 2 + 2pq + q squared 2 = 1

p squared 2 = homozygous dominant
q sqaured 2 = homozygous recessive

if only either q OR P is given then use p+q =1 to work out the other and then use the hardy weinberg equation

Question 19

tutipotent

Answer 19

differentiate into any cell type

Question 20

pluripotent

Answer 20

differentiate into many cell type
differentiate into all cell except extra embryonic

Question 21

multipotent

Answer 21

differentiate into limited cell type

Question 22

unipotent

Answer 22

differentiate into one cell type

Question 23

stem cell

Answer 23

treats disease as they produce healthy cells needed by the patients and prevent the production of faulty cell, and due to single stem cells keep on dividing which means single treatment has long term impact

Question 24

ethical issues of embryos

Answer 24

destroyed during stem cell collection

Question 25

ethical issues of foetus

Answer 25

foetus must be aborted or miscarried

Question 26

ethical issues of adult bone marrow

Answer 26

harvesting adult bone marrow is painful and can be risky for donor

Question 27

induced pluripotent

Answer 27

formed from unipotent cell whivch are genetically altered to enable translation of additional in the cells DNA, these behave like a pluripotent cell

Question 28

what does SER

Answer 28

synthesises and processes lipids the look similar to RER but have no ribosomes

Question 29

what does RER

Answer 29

folds and processes proteins that have been made at the ribosomes

Question 30

ribosomes

Answer 30

80s is eukaryotic and 70s is prokaryotic site where the proteins are translated

Question 31

lysosomes

Answer 31

contains digestive enzyme

Question 32

Golgi apparatus

Answer 32

process and packages new lipids and proteins looks more like a wifi

Question 33

centrioles

Answer 33

separation of chromosomes

Question 34

structure of prokaryotic cell

Answer 34

cytoplasm, plasma membrane, cell wall, pili, mesosomes, chromosomal DNA, flagellum

Question 35

pili

Answer 35

hair like structure help to stick other cells

Question 35

prophase

Answer 35

chromosomes condense nuclear envelope breaks down

Question 36

metaphase

Answer 36

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

Question 37

anaphase

Answer 37

centromere divide, seperating each pair of sister chromatid

Question 38

telophase

Answer 38

chromatids reaches the opposite poles on the spindle they uncoil and long nuclear envelope forms around each groups of chromosomes

Question 39

mitotic index

Answer 39

number of cells with visible chromosmes / total number of cells

Question 40

behavioural

Answer 40

ways an organisms acts that increases chances of survival

Question 41

physiological

Answer 41

proceeses inside a organisms body that in crease its chances of survival

Question 42

anatomical

Answer 42

structural features of an organisms body that increases its chance of survival

Question 43

advantages of seedbanks

Answer 43

its cheaper to store seeds then fully grown plants large number of seeds than fully grown plants because they need less plants seeds can be stored anywhere

Question 44

disadvantages of seedbanks

Answer 44

testing the seeds for viability can be expensive and time consuming may be difficult to collect seeds from plants as they may grow in remote collections

Question 45

xylem cells

Answer 45

transports water and mineral ions and also provides support formed from dead cells have hallow lumen and have no end walls which allows water and mineral ions to pass through easily their walls are thickened with lignin water and mineral ions move into and out of the xylem through pits in the walls where there is no lignin

Question 46

Schlerenchyma

Answer 46

made up from dead cells have hallow lumen and have a end wall they are also thickened by lignin but have no pits they have more cellulose

Question 47

ploem

Answer 47

arranged in tubes like xylem contains types of sieve tubes and companion cells translocation

Question 48

sieve tube in the phloem

Answer 48

are living cells and joined end to end. the seive parts are the end walls which have a lot of holes which allows solutes to pass through lack of nucleus and lack of other organells means they can survive alone and there is a companion cell for every sieve tube cells

Question 49

companion cells

Answer 49

carry the living function for both themselves and their sieve tube elements.

Question 50

starch

Answer 50

alpha glucose - amylose and amylopectin amylose - unbranched chain of alpha glucose, coiled making it compact amylopectin - branched chain of alpha glucose starch is insoluble, glycosidic bonding

Question 51

cellulose

Answer 51

long, unbranched chains of beta glucose joined by 1-4 glycosidic bond cellulose chains are straight

Question 52

primary cell wall

Answer 52

cellulose microfibrils in a net like struc

Question 53

secondary thickening of the cell wall

Answer 53

secondary cell wall is thicker than the normal cell wall as it has more lignin

Question 54

vacuole

Answer 54

contains cell sap and surrounds tonoplast.

Question 55

cell wall

Answer 55

made up of cellulose

Question 56

captive breeding programme

Answer 56

which endagered species are carefully bred to increase genetic diversity and population size

Question 57

genetic diversity is maintained by

Answer 57

keeping stud books, prevent interbreeding

Question 58

magnesium ions

Answer 58

involved in chlorophyll production

Question 59

nitrate ions

Answer 59

supply nitrogen for RNA, DNA, Proteins, Chlorophyll

Question 60

calcium ions

Answer 60

are a component of the plant cell wall, they form calcium pectate