Inheritance 1 Flashcards
(74 cards)
0
Q
Process of ‘runners’ asexual reproduction
A
Overground ariel stems which grow roots to develop new plants
E.g. Wild strawberry
1
Q
What is the difference between asexual and sexual reproduction?
A
Asexual production
- 1 parent
- offspring identical to each other and the parent
- faster + requires little energy
- e.g. In bacteria, protoctista
Sexual reproduction
- 2 parents
- offspring is non-identical
- produces variety
- e.g. In humans and animals
2
Q
Process of ‘rhizomes’ asexual reproduction
A
Underground stems which travel and then grow up through the soil
E.g. Asparagus
3
Q
Process of ‘tubers’ asexual reproduction
A
Underground swollen stem from which new plants may grow
E.g. Potato plant
4
Q
Process of ‘bulb’ asexual reproduction
A
Underground storage organ made from adapted leaves, new plant grows inside
E.g. Onion bulb
5
Q
What is the process artificial method for reproducing plants called ‘cutting?
A
- a small amount of the parental plant is removed e.g. A leaf
- this small amount , called the cutting, is then placed in new soil and grows into an independent plant
6
Q
What is a explant?
A
A small part of a plant
7
Q
What is the process of the artificial way of reproducing plants called ‘Micropropagation’?
A
- a few cells or an explant is taken from a plant
- this is then placed in a cultured medium for its growth (an altered medium will give a slightly different plant)
- it will then grow into a callus, then a plantlet and the an adult plant
8
Q
Definition of fertilisation
A
Fusion of male and female gametes
9
Q
Why does micropropagation work?
A
- plants contain meristem cells which are actively undergoing mitosis
- these cells are totipotent and can change (differentiate) into all kinds of other plant tissue
10
Q
Why clone plants? (6 reasons)
A
- To produce genetically identical copies of a plant with desirable characteristics
- to quickly produce many mature plants
- to produce plants in the absence of pollinators
- to conserve rare or endangered plants
- to make copies of plants which have been genetically modified
- to produce plants that do not grow easily from seeds
11
Q
Where is DNA found?
A
DNA is contained in chromosomes, which are found in the nucleus of most cells.
12
Q
Characteristics of a DNA molecule
A
- It is a double helix structure that has been twisted
- It consists of 2 strands of nucleotides linked together
- Each nucleotide consists of phosphate, sugar and a base
- The phosphate and sugar form the backbone of the DNA and the bases are in the centre
- There are 4 bases in DNA: A, C, G, and T
13
Q
Which bases always pair up together?
A
A and T
C and G
14
Q
How are the bases held together?
A
By hydrogen bonds
15
Q
What are the names of all the bases?
A
A = adenine T = thymine C = cytosine G = guanine
16
Q
Definition of gene
A
A small section of DNA in a chromosome that has the code for making a protein
17
Q
Definition of a protein
A
Chain of amino acids
18
Q
How many bases make up 1 amino acid code?
A
3 bases = 1 amino acids code
19
Q
What are proteins responsible for?
A
Certain characteristics
E.g. eye colour
20
Q
What is mitosis?
A
The division of a diploid cell
21
Q
Way to remember the stages of mitosis
A
Isabel's Pork Pies Make Alan Traley Crazy
22
Q
What is the first step of mitosis and what happens?
A
Interphase
- DNA is copied
- Chromosomes are not visible
23
Q
What comes after interphase in mitosis and what happens?
A
Prophase
- chromosomes condense and can now be seen
- each chromosome is seen to consist of 2 chromatids
24
What comes after prophase in mitosis and what happens?
Prometaphase
- the nuclear membrane disappears
- spindle fibres are formed
25
What comes after prometaphase in mitosis and what happens?
Metaphase
| - the chromosomes align on the 'equator' of the spindle
26
What comes after metaphase in mitosis and what happens?
Anaphase
| - spindle fibres pull the chromatids apart to opposite ends of the cell
27
What comes after anaphase in mitosis and what happens?
Telophase
| - a new nuclear membrane forms around each of the 2 sets of chromosomes
28
What comes after telophase in mitosis and what happens?
Cytokinesis
- the cell starts to divide
- 2 new genetically identical daughter cells are formed
29
What is the result of mitosis?
Mitosis leads to the production of an identical cell
30
Where does mitosis happen?
- in all body parts (except sex cells)
- in bacteria and other micro organisms
- in plants
31
What's the purpose of mitosis?
- To make more cells
- to replace dead cells
- asexual reproduction
32
What does transgenic mean?
The transfer of genetic material from one species to a different species
33
Definition of genetic engineering
The artificial change of DNA in a cell either by adding, changing, or removing DNA
34
What is a plasmid?
A short circular piece of DNA found in bacterial cells
35
What is a restriction enzyme?
Enzyme that cuts DNA molecules at specific points
36
What is a DNA ligase?
Enzyme that joins cut ends of DNA molecules
37
What is recombinant DNA?
DNA that has been created from different sources
38
What is a vector?
The means of transferring DNA into an organism
| E.g. A plasmid or a virus
39
What is a transgenic organism?
An organism whose DNA has been genetically altered and contains DNA from another species
40
Describe the process of making insulin up to recombinant DNA
- DNA is extracted from human cells because they contain the gene for making insulin
- The insulin is cut out of the DNA using a restriction enzyme
- A plasmid is extracted from a bacteria cell
- The plasmid is cut using the same restriction enzyme
- The enzyme, DNA ligase is used to join the ends of the insulin gene and plasmid DNA
- This creates recombinant DNA
41
Describe the process of making insulin from the recombinant DNA
- The plasmid holding the insulin gene functions as a vector
- It is used to transfer the insulin gene into a bacteria cell
- The transgenic bacteria cells now reproduces and starts making insulin protein
- The insulin gene can now be isolated and purified
42
What is are clones?
Genetically identical cells or organisms
43
Describe the process of embryo splitting when making animal clones
- Sperm is taken from the male animal
- The female is artificially inseminated with sperm
- A zygote forms and develops into a early embryo
- The embryo is split into several smaller embryos
- These embryos are placed into the uterus of several foster mothers
- Genetically identical offspring are born
44
After embryo splitting has taken place who are the offspring identical to?
- When the offspring are born, they are identical to each other.
- They are not identical to their foster mothers, because they contain different genetic information (the offsprings' DNA comes from the original pregnant animal and the father).
45
Steps for genetically modified plants
- The desired DNA gene is inserted into the plasmid
- This creates a recombinant plasmid
- The plasmid is introduced into plant cells and cultured in a laboratory
- The plant cells develop into fully grown plants
46
How many pairs of chromosomes are there in the nucleus?
23 pairs
- 22 pairs of homologous chromosomes
- 1 of sex chromosomes
47
What does a duplicated chromotid consist of and what is it called?
Called a chromosome
Consist of 2 identical chromotids
Held together by the centromere
48
Definition of The Genetic Code
The rules (code) by which the information encoded in the DNA sequence is translated into the amino acid sequence
49
Process from gene to characteristics
Gene --> amino acids arrange themselves in a specific order --> that protein causes a certain characteristic (eye colour)
50
Definition of gene therapy
The insertion alteration or removal of gene within cells to treat genetic diseases
51
Definition of GMF
Genetically modified foods
52
Definition of gmo
Genetically modified organisms
53
Definition of gt
Gene therapy
54
Definition of DNA replication
The coping of DNA molecule to obtain two identical DNA molecules
55
Result of DNA replication
the newly formed DNA molecules contain one strand of original parental DNA and one new identical strand
56
What is the process of DNA replication also called
Semi-conservative
57
Steps of DNA replication
- original DNA unwinds are separates
- New DNA strands form through complimentary base pairing between exposed bases of original DNA and free nucleotides
- 2 new strands have been created
- DNA winds back up into helical structure
58
What happens to chromosomes due to DNA replication?
A new 'sister' chromosome forms creating a duplicated chromosome
59
Describe the process of reproductive cloning
- A adult cell is removed from Animal A and the nucleus is extracted
- A egg cell is removed from female Animal B and the nucleus is removed leaving a empty cell
- A mild electric shock fused the empty cell and the nucleus together
- Mitosis takes place and produces an embryo
- The embryo is implanted into Animal C
- The offspring of Animal C will be a clone of Animal A
60
Advantages to genetically modified plants
- Resistance to herbicides + pesticides
- Resistance to plant diseases
- Drought and heat tolerance
- Better balance of nutrients or additional nutrients to improve food production
- Extended shelf-life of fruit vegetables
- Production of biodegradable plastics
61
Advantages to pluripotent embryonic stem cells
- Able to form most types of cells , differentiate into other cells
- Limitless self renewal
- Large numbers can be obtained
62
Disadvantages to pluripotent embryonic stem cells
- Embryos are destroyed
| - These don't have the same genes as the person treated with them so they might be rejected
63
Advantages to multipotent umbilical cord stem cells and adult stem cells
- Can be isolated without causing harm to the patient
| - Use of patients own cells is possible so the cells will not be rejected
64
Disadvantages to multipotent umbilical cord stem cells and adult stem cells
- Small number found in body
| - Difficult to work with
65
Definition of totipotent
Can develop into any type of cell/cell type
66
Definition of pluripotent
Can develop into most cell types
67
Definition of multipotent
Can develop into some cell types
68
Definition of unipotent
Can develop into one cell type
69
Definition of stem cells
Cells that can:
- replicate themselves
- and differentiate into other cell types
70
Steps for therapeutic cloning
- A person needs new organ tissue has a adult cell removed and the nucleus is extracted
- A human ovum is removed from a female the nucleus is removed leaving a empty cell
- A mild electric shock fuse the empty cell and the nucleus together
- A new pre-embyro cell containing patient DNA has been formed
- Embryonic development begins, the numbers of cells increase
- Stem cells are removed from embyro and are cultured to grow into required organ or tissue
71
What is the sugar used in DNA called?
Deoxyribose
72
Why clone animals?
- For prevention of the species extinction
- Agricultural benefits = £££
- Money, e.g. Clone a good racehorse
- Organ donors
- Medical trials
- Personal attachment e.g. Dog after dead
73
Why are some people opposed to animal cloning?
- Inbreeding
- Loss of variation
- Life is sacred, value of life
- Could lead to human cloning
- Not very reliable, loss of money, abnormal deficiencies
