6 Variation And Reproduction Flashcards
In which part of a cell is the genetic information found?3
It is found in the nucleus of your cells
The nucleus contains chromosomes chromosomes carry the genes that control the characteristics of your body
Why does asexual reproduction result in offspring that are identical to their parents?2
In asexual reproduction there is no joining of gametes and only one parent
Thus there is no genetic variety in the offspring
How does sexual reproduction produce variety?2
- male female gametes join
- the mixture of genetic information from two parents leads to variety in the off spring
What is a clone?
Identical offspring
How do parents pass on genetic information to their offspring?
In their sex cells ( gametes )
What, other than genetics allows for variety?3
The environment you grow up in
Eg lighter hair in a sunnier place
Darker skin in a sunnier place
How do we clone plants? 2
By taking cuttings from mature plants
The new plants are genetically identical to the older ones
How do we clone animals?
By transplanting cloned embryos is one way animals are cloned
Why do we want to create clones? 3
- So that high quality embryos can be transported all around the world
- They can be carried to places where they are needed because of poor local stock
- embryos are also cloned so that lots of copies of genetically modified embryos with medically useful compounds can be made
What are the benefits of adult cell cloning?3
- to save animals from extinction
- bring back species of animals that died years ago
- large numbers of medically useful animals
What are the disadvantages of adult cell cloning?2
- could lead to designer babies
- reduces variety in the population
What is genetic engineering?2
- genes can be transferred to the cells of animals and plants at an early stage of their development
- so they develop desired characteristics
How are genes transferred from one organism to another?2
- genes from the chromosomes of humans and other organisms
- can be cut out using enzymes transferred to the cells of bacteria and other organisms
Environmental factor that might affect the number of peas in a pod?
Lifht
Rain
Water
Temperature
Alternate factor that might affect the number of peas in a pod?
Genes (inheritance)
Disease
What is the difference between sexual reproduction and asexual reproduction?
Only one parent in asexual
No mixing of genetic material in asexual
No gametes in asexual
No variation in asexual
Why is adult cell cloning a type of asexual reproduction?
Nucleus of egg removed so only one set of genetic information
Difference between asexual and sexual reproduction?
No fusion of gametes
No mixing of chromosomes
No genetic variation
Explain a sexual reproduction?
Two pairs of chromosomes (4) are copied
This forms a cell with 4 pairs of chromosomes
Which then divides
To form two cells with two pairs which were identical to the parent cell
What is asexual reproduction used for?
Growth in plants and animals
Replacement cells
What do humans have in terms of chromosomes?
46 chromosomes
23 pairs
Explain sexual reproduction?
Sperm and egg fuse together in fertilisation
Characteristics from both parents inherited in new cell
Asexual production - variety or clones?
Clones
sexual production - variety or clones?
Varitety
How can you clone plants?
Using cuttings (cheap and quick) Or Tissue culture (more expensive but quick little space needed and grown all year)
How do you clone plants by cuttings?
Take cuttings from good mature parent plants in the stem or leaf
Keep in moist conditions untill planted
Plant grows into a genetically identical plant
Explain how plants can be cloned using tissue culture?
Extract plant cells Use hormones to stop differentiation Spilt them Add hormones with sugars and vitamins to encourage growth Grow into small plants Replant individually
How can you clone animals?
Embryo transplants or adult cell cloning
Explain adult cell cloning with sheep?
Adult cell eh skin cell extracted from sheep a
Nucleus extracted
Mature (unfertilised) egg cell extracted from sheep B
Nucleus removed from egg cell
Nucleus added to blank cell
Fused using electric shock
Fused cell divides normally
Implanted into the uterus of sure where sheep
Embryo develops normally
Explain cloning using embryo transplants?
Best sperm cells from bull and best egg cells from a cow extracted
Sperm artificially fertilised cell
Each embryo divides into ser real individual cells
Rach cell grows into an identical embryo in a lab
Embryo transferred to a host mother
Given hormones to ready for pregnancy
Identical calves are born
Issues with cloning of animals?
Might not be healthy as matur cells used Worry of human cloning Reduced gene pool Reduced resistance to disease Preserved endangered species Greater understanding of embryos or she
Cons of genetically modified crops?
May not be safe
Reduced biodiversity
Poor countries miss out
May not be contained resistant weeds
Pros of genetically modified crops?
Already grown without issues Less effort for farmer Increased growth Engineered to contain more nutrients Increased yield
How can GM crops be resistant to?
Viruses
Insects
Herbicides
Explain genetic engineering?
Human cell with desired gene cut out
Bacterium with with a ring of DNA called plasmid
Plasmid cut out using enzyme
Insulin gene inserted into plasmid using another enzyme
Plasmid with insulin inserted into bacterium
Multiplies many times
Insulin purified for use and harvested
Definition of sexual reproduction?
Fusion of gametes
Egg and sperm cell fertilised
Why would a child have the characteristics of its parents?
Through sexual reproduction
Contains a mixture of genetic information
From both Barents
FSH and LH in the menstrual cycle?
FSH stimulates oestrogen
Oestrogen inhibits FSH
Oestrogen stimulates LH to release egg
Describe what happens at the synapse during a reflex?
Chemical release
Which diffuses across the synapse
Which transmits information
Between neurones
Describe IVF?
Eggs collected from ovary Eggs mixed with sperm Fertilised egg divided Embryo formed and inserted into womb FSH matures egg and LH releases egg
What is sexual reproduction?
Fusion of gametes and sperm : sex cells
In adult cell cloning, what is the embryo a clone of?
The Abimal that gave the nucleus
Genetic engineering?
Moving genes between species eg human insulin
Describe genetic engineering?
Cut human insulin gene out with an anzyme
Remove DNA plasmid from bacteria
Cut open with enzyme
Add human insulin gene into the plasmid
Insert back into bacteria with new plasmid
Multiples and secretes insulin
Features of asexual reproduction?
No fusion of gametes
One parent
No genetic variation
Clones p
Concerns about GM crops?
Effect on populations of wild flowers and insects
Uncertainty about the effects of eating them on human health
Damage food chain
Gene spread to other species
Examples of GM crops?
Crops that are resistant to insect attack
Herbicides
Why is it an advantage to make crops resistant to a herbicide?
Kills weeds among crops (and does not kill crops)
Less competition for light water or irons
Crops grow better (higher yield obtained)
How does a sharp point reach a mans brain?
Sharp point stimulates pain receptor To send nerve impulse Via sensory neurone To spinal cord Crossed synapse To other relay neurones (go brain)
How could a gene be transferred to a plant?
Gene cut out From bacterial chromosome (plasmid) Using an enzyme Gene spliced into plant chromosome Gene added at early stage of development
How does embryo transplants work?
Splitting apart cells from a developing Abimal embryo before they become specialised
Then transplanting the identical embryos into host mothers
How does tissue culture work?
Using small groups of cells from part of a plant
Advantages of using cuttings instead of seeds?
Quick
Cheap and many can be produced from one plant
Why might people be against feeding an animal GM food?
Effect on cow healthy
Effect on human health
Concern about food chain
Effect on gene pool
How do plants clone by tissue culture?
Plant cells which are put in what with hormones to encourage growth
They grow into small plants
Replaced individually
Advantages of tissue culture?
Quick
Little space
Grown all year
1000s of clones
