week 2

Question 1

what is DNA/ what is its made from/ which bases go together

Answer 1

deoxribosenuliec acid / Double stranded helix -> sugar phostphate bace nitrogenous base and a phosphate head // A-T // G-C

Question 2

gene

Answer 2

a hereditay unit At a specific location on a chromosome
Code for a specific protein or enzyme to be made

Question 3

allele

Answer 3

alreternate DNA sequencce verison of a gene

Question 4

genotype

Answer 4

the two allels for the gene

Question 5

phenotype

Answer 5

outcome of the physical expression of the protein produced by the two allels (genotype)
Can be altered by enviornment eg sun

Question 6

mitosis

Answer 6

prophase- chromosomes become condensed and viable/ spindle fibres form/ nuclear envelop breaks down/ centresoles move to opposite sides of the cell

pro metaphase- kinetochores appear at the centimetres & mitotic spindle fibres attach to kinetochores

metaphase- chromosomes line up on the metaphase plate / each sister chromatid attaches to a spindle fibre orienting from the other side of the cell

anaphase- centromeres split in two / sister chromotides are pulled to the other side of the cell/ certain spindle fibres being to elongate the cell

telophase- nuclear envelop surrounds each set off chromosomes / spindle fibres continue to push poles apart

cytokineses- animal cells: a cleavage furrow separates the daughter cells
plant cells: a cell plate separates the daughter cells

Question 7

meiosis

Answer 7

goes through mitosis 2

Question 8

difference between mitosis and meiosis respectively

Answer 8

chromosomes: 46. 23
daughter cells: 2. 4
identical DC? yes. no
function grown tissue replace body cells///////// provide gametes

Question 9

cell cycle

Answer 9

• Mitosis (cell division) -> interphase (G1,S,G2) -> cell growth and preforms its normal cell functions
  S phase of interphase = where the dna is dublicated

Question 10

DNA protein synthesis

Answer 10

• Transcription: DNA is transcribed into complemetary mRNA undergos rna processing, via complemtart base pairings. Mrna leaves nucleus for the ribosomes

Translation: the trna has specific and complemtary anti codons to the mrna codons and carries a specfic and complemtary amino acid, this binds with the dna to form a polypeptide.

Question 11

Mutation

Answer 11

change in the dna squence for the gene-> new allele

Question 12

dominant allele

Answer 12

expressed in homozygous and heterozygous

Question 13

recessive allele

Answer 13

only expressed in a recessive homozygous

Question 14

Phospholipid bilayer

Answer 14

hydrophilic heads / hydrophoblic tails

Question 15

simple diffusion

Answer 15

Small uncarged lipid soluble molecules eg fatty acid can pass through the membrane

Question 16

facilitaed diffusion

Answer 16

Large or charged or water soluble eg glucose has to pass through bilayer via a protein channel

Question 17

osmosis

Answer 17

WATER needs a channel to move from an area of high water concentration and low solute to an area of low water concentration and high solute (aquaporin=channel)

Question 18

hypertonic

Answer 18

Low is water high in solute

Question 19

hypotonic

Answer 19

High water low solute

Question 20

PRIMARY ACTIVE TRANSPORT

Answer 20

Large charged molecules go against a concentration so requires energy

Question 21

SECONDARY ACTIVE TRANSPORT

Answer 21

Simport- two things are moving at once requires atp bc NA comes in w glucose with the concentration gradient then NA goes back against the contration gradient requires atp to allow the cell to return to homeostatis

Question 22

what is crenation of a RBC

Answer 22

the cell shrivels up as water has moved out of the cell

Question 23

what is isotonic of a RBC

Answer 23

no net movement of the water as water moves evenly in and out

Question 24

what is swelling/ bursting of a cell

Answer 24

when water moves from a hypotonic solution into cells and the cells swells then may also burst