Mr P bio 5 cells

Question 1

what is the purpose of the nucleus?

Answer 1

contains the DNA necessary for controlling the cell

Question 2

what is the structure of the nucleus?

Answer 2

surrounded by a double membrane which is perforated by pores called nuclear pores (to allow passage of large molecules such as RNA), in nucleus is the nucleolus and chromatin

Question 3

what is the function of the nucleolus?

Answer 3

site of ribosomal RNA synthesis

Question 4

what is chromatin? (in nucleus)

Answer 4

made of DNA and coiled around protein, during cell division chromatin comes together and forms the thread like structures called chromosomes

Question 5

is the mitochondrion made from a double or single membrane?

Answer 5

double

Question 6

what are the folds in a mitchondrion called?

Answer 6

cristae

Question 7

what do cristae do?

Answer 7

increase the surface area for enzymes for respiration

Question 8

what is the name of the flattened sacs that are a part of the golgi and endoplasmic reticulum?

Answer 8

cisternae

Question 9

what is the function of the rough endoplasmic reticulum?

Answer 9

transports proteins throughout the cell

Question 10

what type of cells contain lots of RER?

Answer 10

cells which make a lot of proteins i.e. secrete enzymes or antibodies

Question 11

what is the function of the Smooth endoplasmic reticulum?

Answer 11

to synthesize lipids, carbs and steroids

Question 12

what is the structure of ribosomes? (3)

Answer 12

made up of two sub units, contain ribosomal RNA and protein, very small only 25nm in diameter

Question 13

what is the function of the Golgi apparatus?

Answer 13

it sorts modifies and packages molecules (like proteins) produced by the cell, into vesicles

Question 14

what is the structure of the golgi?

Answer 14

composed of flattened sacs made of membranes. the sacs are fluid filled and pinch off smaller sacs (vesicles) at their ends

Question 15

what is the function of the lysosomes?

Answer 15

used to break down unwanted structures within the cell

Question 16

what is the structure of the lysosomes?

Answer 16

bound by a single membrane and have no internal structure, contain a large number of hydrolytic enzymes

Question 17

what is the function of the cell membrane?

Answer 17

controls the passage of molecules in and out of the cell

Question 18

what is the structure of the cell membrane?

Answer 18

made up of phospholipids, proteins and carbs

Question 19

what are microvilli?

Answer 19

finger like projections of the cell membrane, which increase the SA of the cell membrane greatly

Question 20

what is the structure of centrioles?

Answer 20

hollow fibers made of microtubules

Question 21

what do two centrioles at right angles to each other form?

Answer 21

a centrosome

Question 22

what is the cytoskeleton made up of?

Answer 22

microtubules

Question 23

what is the function of the cytoskeleton?

Answer 23

to provide support and movement to the cell

Question 24

what are the cilia?

Answer 24

hair-like projections made from microtubules

Question 25

what do cilia allow?

Answer 25

movement of substances over the cell surface

Question 26

what do flagella consist of?

Answer 26

microtubules

Question 27

what is the flagella’s function?

Answer 27

contract to provide cell movement (e.g. in sperm cells)

Question 28

what is the process of binary fission? (briefly)

Answer 28

the cells contents doubled any plasmids undergo DNA replication, the parent cell divides into two cells with the cytoplasm split roughly between the two cells, the two daughter ells each contain a single copy of the circular DNA molecule and a variable number plasmids

Question 29

why can viruses not be described as cells?

Answer 29

they have no cell membrane

Question 30

what do viruses need to be able to synthesise protein or DNA to make coped of itself?

Answer 30

a host

Question 31

what is the structure of a virus? (2)

Answer 31

contains genetic material- DNA, RNA, single or double stranded, surrounded by a protein coat called a capsid, some have an outer envelope of cell membrane which originates aspart of the host cell