Inheritence Flashcards
An undifferentiated cell that has the potential to differentiate into any cell type
Stem cell
A double helix shaped molecule that contains genetic information and makes up chromosomes
DNA
A region of a chromosome that contains the information for making a protein
Gene
Method of making clones from plants by removing a small amount of the parent plant, after planted it then grows into an independent plant
Cuttings
Small changes between individuals of the same species (result of sexual reproduction)
Variation
A constricted region in the middle of a chromosome that holds the chromatids together
Centromere
Reproduction without fusion of gametes
Asexual reproduction
Discoverer of DNA structure
James Watson/Francis Crick
Cell organelle where DNA is found
Nucleus
Reproduction that involves fusion of gametes
Sexual reproduction
Female scientist working on discovery of DNA structure
Rosalind Franklin
Sugar that is part of the backbone of DNA
Deoxyribose
Part of the backbone of DNA
Phosphate
Part of a DNA molecule (A,C,T,G)
Base
First mammal to be cloned
Dolly the sheep
A chain of amino acids
Protein
Genetically identical cell
Clone
Thread like structure in the nucleus made of DNA
Chromosome
One half of a duplicated chromosome
Chromatid
Method of making clones from plants using only a few cells
Micropropagation
The technology of modifying the genome of an organism
Genetic engineering
Cell division which leads to production of genetically identical cells
Mitosis
X or Y
Gender chromosome
The process of making a copy of DNA
DNA replication
Mitosis is when…
A cell produces itself by splitting to form two identical offspring
Meiosis…
Produces cells which have half the normal number of chromosomes
Gene
A small region of DNA (a small par of the chromosome)
Protein
A chain of amino acids that lead to the expression of certain characteristics
How many bases code for an amino acid
3
How many pairs of chromosomes do you take from each parent
23
How many pairs of somatic chromosomes and sex chromosomes do you receive from each parent
22
1
Each pair of somatic chromosomes consist of one chromosome from the … And one from the …
The chromosomes in each pair are called …. Chromosomes (same) because the contain the same genes
Mother
Father
Homologous
After 23 pairs of chromosomes from each parent have joined after fertilisation, a …. Is formed (fertilised egg) for …. To occur. Then ….. Happens to these multiplying chromosomes.
Zygote
Mitosis
Specialisation
Meiosis occurs when either a male or female is making a …..
Sex cell
Label and recognise diagrams of meisos
Label and recognise diagrams of mitosis
What is the advantage of meiosis to the next generation of individuals
It allows variation
Go step by step through mitosis
- interphase: DNA is copied
- prophase: chromosomes become visible under a microscope
- prometaphase: nuclear membrane disappears and spindle fibres are formed
- metaphase: the chromosomes align on the ‘equator’ or the spindle, nuclear membrane gone
- anaphase: the spindle fibres pull the chromatids apart
- telophase: two new nuclear membranes are formed
- cytokinesis: the cells start to divide, two new genetically identical daughter cells are formed
- I Probably Participate More After Taking Cocaine
We use mitosis for…
Growth and repair of cells
Mitosis occur in…
All body cells (except sex cells)
In plants
In bacteria and other microorganisms
Meiosis is when …
A special type of cell division occurs by which gametes are formed
Diploid
Complete set of chromosomes
Haploid
One set of chromosomes
Go step by step through meiosis
- interphase: normal diploid cell
- continued: chromosomes are copied (DNA replication)
- prophase 1: homologous chromosomes pair up and crossing over occurs, the nucleus membrane breaks up
- metaphase 1: chromosome pairs align at the equator if the cell (spindles needed), random arrangement of chromosomes from mother to father (independent assortment)
- anaphase 1: chromosomes move to opposite ends of cell
- telophase 1: new nuclear membranes form around each new nucleus
- cytokinesis/prophase 2: the cytoplasm divides, the chromosomes are tightly coiled ready for the next part of division
- metaphase 2: chromosomes align at equator of cell (notice they are not in pairs as they are in metaphase 1)
- anaphase 2: chromatids move to opposite ends of cells
- telophase 2: new nuclear membranes from around each new nucleus
- cytokinesis 2: the cytoplasm divides (this is the end of the second cell division in meiosis)
- I Can Press My Anus To Cum More Angelically Than Camilla
What does meiosis lead to
The production of four genetically different cells with only half the number of chromosomes
Where does meiosis/ mitosis take place
Ovaries and testes
Body cells except sex cells
How many rounds of cell division are there in meiosis/mitosis
2
1
How many cells are produced in meiosis/mitosis
4
2
What happens to the chromosome number in meiosis/mitosis
Halves
Stays the same
Are parent and daughter cells genetically identical in meiosis/mitosis
No
Yes
Are all daughter cells identical meiosis/mitosis
No
Yes
Environmental variation affects
Characteristics
Genetic variation leads to
- Mutations
- crossing over
- independent assortment
Chromosomes from the mother and father might have different versions of the same type of genes ie eyes AKA
Alleles
Recessive allele
2 copies of the allele are necessary for characteristic to be shown
Dominant allele
Only 1 copy of allele is necessary for characteristic to be shown
Genotype
Genetic make up (what all of the alleles present in the cell nucleus)
Phenotype
The characteristic that is shown (what it looks like)
Homozygous
2 identical alleles
Heterozygous
2 different alleles
Where do new alleles come from
Mutations/sexual reproduction
What are mutations
A change in the order of bases in DNA (genetic code)
Name a type of mutation
Albinism
Change in base leads to change in …. Which causes a change in the …
Amino acid
Protein
Chromosome mutation
Change in chromosome structure or number
Most mutations are
Some mutations are
Very few mutations are
Harmful
Neutral
Beneficial
Describe the relationship between DNA, chromosomes, genes and proteins
- chromosomes are made of DNA
- genes are regions if DNA found on chromosomes
- each gene codes for a protein
- within DNA 3 bases code for amino acids
Mitosis and meiosis chromosomes both … At the beginning
Duplicate
Mitosis has … Division
1
Meiosis has .. Divisions
2
Mitosis makes … … Daughter cells
2
Diploid
Meisos makes … … Daughter cells
4
Haploid
Mitosis produces … Variation
No
Meiosis … Produces Variation
Always produces
Mitosis is for
Growth and repair
Meiosis is for
Gametes
Sex cells
Human cells contain .. Chromosomes
46
What are bases in DNA held together by
Hydrogen bonds
Nucleotide
Unit of DNA made up of phosphate, a sugar and a base
Bases
A and T combine
G and C combine
The bases are in the … Of the helix
Centre
The information for making a particular protein is contained within the… Of the DNA …
Sequence
Bases
… Bases code for … Amino acids
3
1
Proteins are responsible for certain … Ie…
Characteristics
Eye/hair colour
Mitosis happens in
All body cells (except sex cells)
In bacteria and other microorganisms
In plants
Why does mitosis happen
To make more cells (during growth)
To replace dead cells (repair)
Asexual reproduction
The result of DNA replication
- the newly formed DNA molecules contain: one strand of the original parental DNA and one new strand
- called semi-conservative replication
Advantages of asexual reproduction
No partner needed
Faster
Requires less energy
Advantages of sexual reproduction
Produces variety
What does asexual reproduction happen in
Bacteria Protoctista Fungi Plants Some animals
What does sexual reproduction happen in
Fungi
Plants
Animals
Asexual reproduction in plants: runners=
Overground arial stems which grow roots and develop into new plants ie strawberry
Asexual reproduction in plants: rhizomes=
Underground stems which grow through the soil, and will periodically produce new roots and new above ground shoots
Asexual reproduction in plants: tubers=
Underground swollen stem from which new plants may grow ie potato
Asexual reproduction in plants: bulbs=
Short stems with fleshly leaves ie onion
Mitosis leads to the production of two genetically identical cells ie
Clones
Why does plant cloning work
- plants contain meristem cells, which have actively under growing mitosis
- these cells are totipotent and can differentiate into all kinds of other plant tissues
- differentiation in plants is not permanent
6 reasons to clone plants
- to produce genetically identical copies of a plant with desirable characteristics
- for production speed
- produce plants in absence of pollinators
- conserve rare/endangered species
- to make copies of GM plants
- produce plants that dont grow easily from seeds (orchids)
8 steps of plant life cycle
Mature flowering plant Pollination Fertilisation Embryo Fruit and seed Seed dispersal Germinating seed Seedling
Male parts of a plant
Anther and filament to make stamen
Pollen grain - male gametes
Female parts of a plant
Stigma style and ovary to make carpel
Ovule - female gametes
Fertilisation in a plant
The fusion of male and female gametes
3 steps of fertilisation in a plant
1) the pollen grain lands on the stigma
2) pollen grain develops a pollen tube which grows down the style and makes its way towards the ovary, the nucleus of the pollen grain travels down the pollen tube
3) the male nucleus enters the ovule and fuses with the female nucleus
Fruit and seed formation steps
- the fertilised ovule develops into a seed (which contains the plant embryo)
- food store for the plant embryo to be used in germination
- seed dispersal as fruit gets eaten by animals
- the ovary wall develops into a fleshy fruit or hard covering in case of nuts which surrounds seeds
Germination
The development of a plant from a dormant seed
Germination steps
- water intake
- triggers enzymes to breakdown stored food
- first root and first leaves (embryo) appear
- seedling starts to grow
How to genetically modify plants
- the desired gene is inserted into the plasmid
- the plasmid is introduced into plant cells cultured in a laboratory
- the plant cells develop into full grown plants
6 things to make use of GM plants
- resistance to herbicides and 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 and vegetables
- production of biodegradable plastics
What is gene therapy
The insertion, alteration, or removal of genes within cells to treat genetic diseases
In genetic engineering a plasmid is … And … Using restriction enzymes. Some DNA is extracted from a human cell, insulin is cut from the DNA using the … restriction enzymes. Enzyme DNA (…) join ends of insulin gene and plasmid to create a round … DNA. Plasmid holding insulin gene functions as a vector and is used to transfer insulin gene in bacteria. … bacteria reproduce and start making insulin protein. Insulin protein … and …
Extracted Cut Same Ligase Recombinant Transgenic Isolated Purified
2 types of vector
Plasmid
Virus
Plasmid
Short circular piece of DNA found in bacterial cells
restriction enzyme
Enzyme that cuts DNA molecules at specific points
DNA ligase
Enzyme that joins cut ends of DNA molecules
Recombinant DNA
DNA that has been created from different sources
Vector
The means of transferring DNA into an organism eg plasmid or virus
Transgenic organism
An organism whose DNA has been genetically altered containing DNA from another species
Steps of embryo splitting
- sperm is taken from a bull from a high yield dairy herd
- cow is artificially inseminated with sperm
- zygote forms and develops into early embryo
- embryo is split into several smaller embryos
- embryos are placed in uterus of several foster mothers
- genetically identical calves are born
Steps of reproductive cloning
- isolate nucleus from adult cell
- remove nucleus from an egg cell
- mild electric shock
- nucleus from adult cell and empty egg cell fuse
- mitosis produces an embryo
- embryo implanted into sheep
- lamb born as a clone of the adult cell sheep
Arguments for cloning animals
- increase productivity
- conserve endangered animals
- reproduce desirable characteristics
- use as organ donors
- use clones in medical trials
- bring animals back to life that died years ago
- to clone animals that have been genetically enginered
Arguments against animal cloning
- not reliable
- shorter life of cloned animals
- high risk of bacterial diseases during birth
- likely to be born with a disability
- morally wrong
- expensive
- could lead to cloning of humans
- reduces variation
Stem cells can…
Replicate themselves and differentiate into other cell types
Totipotent stem cells
Can develop into any cell type
Pluripotent stem cells
Can develop into most cell types
Multipotent stem cells
Can develop into some cell types
Unipotent stem cells
Can develop into one cell type
Development of baby cells
Day 1-4 zygote (totipotent)
Day 5 morula (totipotent)
1 week blastula (pluripotent)
Foetus, baby, adult (multipotent)
Advantage of pluripotent stem cells
Easily make more via mitosis so large yield obtained
Disadvantage of pluripotent stem cells
Embryos are destroyed as dont have same genes as the person treated so may be rejected by the body
Advantage if multipotent stem cells
Can be isolated without causing harm to the patient, use of patients own cells is possible therefore no rejection
Disadvantage of multipotent stem cells
Only small numbers can be found in the body, difficult to work with
Therapeutic cloning steps
-person who needs new organ or tissue
-adult cell from patient, isolate nucleus
-human ovum with nucleus removed so empty
-mild electric shock
-new pre embryo cell containing
patient DNA
-embryonic development begins
-stem cells removed from embryo and cultured to grow into required organ or tissue
