cell organelles

Question 1

prokaryotes

Answer 1

unicellular organisms eg bacteria and archaea

Question 2

eukaryotes

Answer 2

multicellular eg plants,animals,fungi and protoctists

Question 3

prokaryotes have

Answer 3

70s small ribosomes. cell wall made of peptidoglycan. capsules and plasmids. flagella/pili. cirvcula dna

Question 4

eukaryotes have

Answer 4

membrane bound organelles like nucleus. 80s big ribosomes. no plasmids and no capsules. linear dna

Question 5

both prokaryotes and eukaryotes have

Answer 5

cytoplasm ribosomes and cell membarne

Question 6

ER

Answer 6

network of fluid filled membranes
modifies and folds proteins

Question 7

difference between RER and SER

Answer 7

SER has ni riboosmes and not attached to nucleus

Question 8

function of golgi apparatus

Answer 8

trmoves water from protein
Modify and package proteins
forms vesicles /lysoomses

Question 9

golgi vesicles

Answer 9

Made by golgi apparatus
Store and transport protein and lipids out of the cell

Question 10

lysosomes

Answer 10

Special type of golgi vesicle
Contain digestive enzymes called lysozymes, which are used to hydrolyse pathogens and old cell organelles

Question 11

ribosome

Answer 11

made of protein and RNA

Question 12

nucleolus

Answer 12

makes ribosomes

Question 13

mesosome

Answer 13

in folding of cell membrane
outside the cell wall

Question 14

capsule

Answer 14

protective layer outside of cell wall

Question 15

pilus

Answer 15

transfer plasmids between bacteris

Question 16

locus

Answer 16

location of genes on a chromosome

Question 17

how is dna in bacteria organised

Answer 17

circular dna
located in cytoplasm
small plasmids

Question 18

extracellular enzymes

Answer 18

proteins are foleded in RER
transported in vesicles
vesicles fuse with golgi spparatus
modification of protein inside golgi apparatus
protein packaged into secretory vesicles
exocytosis - vesicles fuse with cell surface membrane

Question 19

cortical reaction

Answer 19

fusion of sperm cell with egg cell membrane
cortical granules release contents
zona pellucida thickens/hardens
fusion of nuceli

Question 20

why do some genes show linkage and some show sex-linkage

Answer 20

there are more genes than there are chromosmes
linkage relates to genes on the same choromseome
sex-linkage relates to genes on the sex chroosmeome

Question 21

fertilised cell divides

Answer 21

by mitosis to produce genticdlly identical cells

Question 22

crossing over

Answer 22

cgromatids are produced with different combinations of alleles. swapping of sections of chormatids.

Question 23

how is acrosome involved in the digestion of the zona pellucida

Answer 23

membrane of the acrosome fuses with the plasma membrane of the sperm cell.
releases digestive enzymes
by exocytosis to break down zona pellucida

Question 24

independednt asortment

Answer 24

different combinations of paternl and maternal chromosmesp[roduced

Question 25

centriole

Answer 25

spimndle organisation

Question 26

polygenic inheritance

Answer 26

more than one gene for a single characteristic at different loci

Question 27

males

Answer 27

can only inherit one allele

Question 28

nucleus

Answer 28

nuclear pores, double membrane/ envelope, nucleolus

Question 29

tonoplast

Answer 29

membrane that surrounds vacuole. controls what enters and leaves the vacuole

Question 30

amyloplast

Answer 30

organelle enclosed by membrane. contain and store starch granules. they convert starch back to glucose for release when the plant requires it

Question 31

pits

Answer 31

thin regions of the cell wall. they allow transport of substances between cells

Question 32

sclerenchyma fibres

Answer 32

provide support and have hollow lumen. it is thickened with lignin. more cellulose than other plants. don't contain pits

Question 33

what happens to lysosomes once their contents have been digested

Answer 33

they fuse with cell surface membrane contents released by exocytosis

Question 34

why cant nucelus be obverved at the end of prophase

Answer 34

nucelar membrane broken down dna is condensed into individual chromosomes

Question 35

function of plasmodesma

Answer 35

cytoplasmic connection between cells allows transport and communication

Question 36

why is protein made by bacteria different to protein made by animals

Answer 36

bacteria do not have rer polypeptide isnt properly modified so protein is incorrectly folded

Question 37

how does preventing shortening of spindle fibres affect mitosis

Answer 37

sister chromatids cannot be separated mitossi stops beofre anaphase

Question 38

why are offspring geneticallt different

Answer 38

random fertilisaiton gamete contains different combinations of alleles due to independent assortment/crossing over

Question 39

sex linked defintion

Answer 39

faulty gene located on x/y chromsome

Question 40

why abnormal sperm reduces fertility

Answer 40

affects motility prevents sperm from reaching egg prevents fertilisation

Question 41

how is corssing over different in sex chromsomes

Answer 41

crossovers cannot form between x and y chromosme because they are not homologous

Question 42

why is dna replicated beefore mitosis beigns

Answer 42

to ensure diploid number of chrosomes in each daughter cell ensure they are geneticlaly identicla

Question 43

prophase

Answer 43

nucelar envelope breaks down chromatids condesne spindle fibres form

Question 44

on sex linked, genes are carried on

Answer 44

x chromsoome

Question 45

molecular phylogeny

Answer 45

molecular differences in DNA in proteins

Question 46

Compare and contrast the results of mitosis and meiosis

Answer 46

both increase number of cells mitosis produces diploiod cells/meiosis haploid meiosis produces genetically different cells/mitosis porduces genetically identical cells mitosis results in 2 daughter cells/meiosis results in 4 daughter cells

Question 47

Explain how epigenetic changes can cause differences in a characteristic.

Answer 47

histone modification/DNA methylation activates genes affecting enzyme production

Question 48

Explain why an individual may have a greater adult height than their biological parents.

Answer 48

height is affected by environment aswell as genotype height is an example of polygenic inheritance so offspring can inherit a mixture of alleles from boith parents more caclium in diet (needed for bone growth)/better healthcare can affect height

Question 49

difference between tissue and system

Answer 49

tissue contains one type of cell system contains many different tissues/organs

Question 50

Describe what happens to proteins after translation and before they are released from cell

Answer 50

RER folds protein. Proteins are packaged into vesicle. Vesicle then transports protein to Golgi apparatus, where it is modified, e.g. adding carb group. Vesicles fuse with membrane. Protein is released by exocytosis

Question 51

primary structure definition

Answer 51

sequence of amino acids joind together by peptide bonds

Question 52

mutation in enzyme causes?

Answer 52

change in active site substrate can't fit in active site substrate-enzyme complexes can't be formed