Inheritance DNA & Evolution - DNA & Inheritance

Question 1

what is DNA classed as and what structure does it have

Answer 1

polymer

double helix structure

Question 2

what is DNA made up of

Answer 2

chromosomes

Question 3

what are genes

Answer 3

small section of DNA found on a chromosome

Question 4

what does a gene do

Answer 4

codes for a particular sequence of amino acid which are put together to make a specific protein

Question 5

how many amino acids are used

Answer 5

20 but they make thousands of different proteins

Question 6

what determines what type of cell something is

Answer 6

dna determines what protein the cell produces that in turn determines what cell it is

Question 7

what is a genome

Answer 7

entire set of genetic material in an organism

Question 8

what is understanding the human genome important for

Answer 8

identifying genes that are linked to diseases
so can develop effective treatment for them

can trace migration of populations of people around the world. Scientist study differences in genome to work out when new pops slit off

Question 9

DNA is made of repeating units called what

Answer 9

nucleotides

Question 10

what do nucleotides consist of

Answer 10

one sugar molecule and one phosphate molecule and one of 4 bases

the sugar and phosphate molecules alternate and the base sticks out

Question 11

what are the 4 bases of DNA

Answer 11

A C G T

Question 12

what decides the order of amino acids in a protein

Answer 12

order of the base in a gene

Question 13

each amino acid is coded by what

Answer 13

sequence of three bases

Question 14

how is DNA kept in a helix structure

Answer 14

each base is linked to a base on the opposite side of the structure.

A pairs with T

C pairs with G

this is called complementary base pairing

Question 15

what do non coding parts of DNA do

Answer 15

switch genes on and off. so control if gene is expressed (used to make a protein)

Question 16

where are proteins made

Answer 16

in cytoplasm on structures called ribosomes

Question 17

what do ribosomes use to know how to make proteins

Answer 17

code in DNA

Question 18

how does the ribosome get the code from the DNA

Answer 18

a molecule called mRNA carriers the copied code and acts as a template

Question 19

how are the correct amino acids brought to the ribosomes in the correct order

Answer 19

by carrier molecules

Question 20

what happens when a chain of amino acids has been assembled

Answer 20

folds into unique shape

Question 21

what are 3 functions of proteins

Answer 21

enzymes
hormones
structural proteins

Question 22

what is a mutation

Answer 22

a random change in an organisms DNA

can sometimes be inherited

Question 23

when do mutations happen

Answer 23

continuously.
e.g spontaneously when a chromosome isn’t replaced properly

chances increase by exposure to certain substances or some types of radiation

Question 24

what do mutations do

Answer 24

change the sequence of DNA bases in a gene which produces a genetic variant

this can lead to changes in the protein it codes for which will effect its ability to perform its function

however most mutations have very little or no effect on the protein

Question 25

what is an example of how a protein may not work due to mutation

Answer 25

collagen could lose strength if shape is changed

Question 26

what are insertions

Answer 26

a new base is inserted into DNA base sequence where it shouldn't be . This causes the way the group of 3 bases for an amino acid is read which can change the amino acid. Insertions can change more than one amino acid as they have a knock on effect on the bases further in the sequence

Question 27

what are deletions

Answer 27

random base is deleted from dna which changes the way the base is read and has knock on effects further down the sequence

Question 28

what is a substation

Answer 28

mutation where random base sequence is changed to a different base

Question 29

what is sexual reproduction

Answer 29

where genetic infomation from 2 organisms is combined to produce offspring genetically different to each parent

Question 30

what does a gamete contain

Answer 30

23 chromosomes so one of each chromosome

Question 31

what is fertilisation

Answer 31

egg and sperm fuse together to form a cell with full number of chromosomes

Question 32

what is asexual reproduction

Answer 32

one parent so clone is identical. happens by mitosis

Question 33

what happens in meiosis

Answer 33

cell duplicates genetic information forming 2 armed chromosomes and arrange themselves into pairs line up in centre of cell then pull apart so each new cell only has one copy of each chromosome they line up and split again then the chrosomes end up random thAT ARE IN THE 4 GANETES FORMED

Question 34

what happens in embryo development

Answer 34

cells divides using mitosis to produce lots of new cells. as embryo develops they begin to differentiate into specialized cells

Question 35

advantages of sexual reproduction

Answer 35

variation because of mixture of 2 sets of chromosomes this increases species chances of surviving a change in environment because individuals willhave charecteristics that make them better adapted they will then breed and ass their characteristics selective breeding speeds up natERAL SELECTION so we can increase food productionon

Question 36

advantages of asexual reproduction

Answer 36

only needs to be one parent so less energy and faster many identical offspring can be produced in favourable conditions

Question 37

how can malaria produce offspring

Answer 37

parasite transfered to human in mosqito bite and produces asexually produces sexually when its in the mosquito

Question 38

what can produce sexually and a sexually

Answer 38

fungus

Question 39

what are runners

Answer 39

stems that grow horizintally away from plant which is an asexual reproductive method by strawberrys