Y11 Mock Cell Biology

Question 1

features of eukaryotic cells

Answer 1

plant and animal cells
have a cell membrane, cytoplasm and genetic material enclosed in a nucleus

Question 2

features of prokaryotic cells

Answer 2

bacterial cells
much smaller
have a cytoplasm and cell membrane surrounded by a cell wall
genetic material is not enclosed in a nucleus , it is a single dna loop and there may be one or more small rings of dna called plasmids

Question 3

what is binary fission

Answer 3

cell division in prokaryotic cells - splits into tqo

Question 4

steps of binary fission

Answer 4

1 circular dna and plasmids replicate
2 the cell gets bigger and circular dna strands move to opposite poles of the cell
3 the cytoplasm begins to divide and new cell walls begin to form
4 the cytoplasm divides and two daughter cells are produced each with one copy pf the circular dna but variable number of plasmids

Question 5

what conditions increase binary fission

Answer 5

warm environment
lots of nutrients

Question 6

preparing an un contaminated culture

Answer 6

1 spray bench with disinfectant
2 on the bottom of a petri dish with agar jelly , mark 3 segments, a dot , and the name of the bacteria in each segment
3 wash hands with antibacterial hand wash
4 place the different antiseptics onto different filter paper discs
5 lift the lid of the agar plate at an angle carefully and use forceps to place each filter paper disc on to the dots. note down the antiseptic applied to each zone
6 tape the lid onto the agar plate securely but loosely enough for oxygen to still reach the bacteria
7 place the agar plate in the incubator at 25 degrees for 48 hours
8 measure diameter of the clear zones after 48 hours. take extra measurements for a mean , then calculate the area

Question 7

what is the cell cycle

Answer 7

where body cells in multicellular organisms divide to produce new cells as a part of a series of stages

Question 8

growth and dna replication section of the cell cycle

Answer 8

before a cell can divide it needs to grow and increase the number of sub cellular structures such as ribosomes and mitochondria
the dna replicates to form two copies of each chromosome

Question 9

mitosis section of the cell cycle

Answer 9

chromosomes line up at the centre of the cell and cell fibres pull them apart
two arms of each chromosome go to opposite ends of the cell
membranes form around each of the sets of the chromosomes and nucleus divides
cytoplasm and cell membrane divide
two new identical daughter cells are produced

Question 10

what is the cell cycle important for

Answer 10

growth, development, and repair

Question 11

what does mitosis do

Answer 11

grow or replace cells that have been damaged

Question 12

what is a stem cell

Answer 12

an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type and from which certain other cells can arises from differentiation

Question 13

where can stem cells come from

Answer 13

embryos
adult bone marrow
meristem tissue

Question 14

what can adult stem cells be used for

Answer 14

to cure diseases eg replace faulty blood cells in patients

Question 15

what can embryonic stem cells be used for

Answer 15

replace faulty cells in patients , make insulin producing cells and nerve cells

Question 16

what is therapeutic cloning

Answer 16

embryo is made to have the same genetic information as the patient
stem cells from the embryo are not rejected by the patients body

Question 17

what is diffusion

Answer 17

the spreading out of particles of any substance resulting in a net movement from an area of a higher concentration to an area of lower concentration

Question 18

what is osmosis

Answer 18

the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

Question 19

what is active transport

Answer 19

movement of substances from a more dilute solution to a more concentrated one against the concentration gradient