extra biology

auxins, uses

• weedkiller, causes the cells to grow too rapidly, killing it

• rooting powder, apply to cutting of a plant, helps plant to grow as its a growth hormone

• promote growth in tissue, when cloning plants, place cells from plant in growth medium containing auxin

genetically modification

• resistant to insect attack, herbicides, generally show increased yield

• bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes

Negatives of IVF

side effects, hot flushes, severe headaches

endocrine system

composed of glands which secrete chemicals, hormones, directly into the bloodstream, blood carries hormone to target organ, produces an effect

controversy, darwin

the mechanism of inheritance and variation wasn’t known until 50 years after theory was published, insufficient evidence at the time to convict many scientists

threaten food security

high input cost, make it too expensive to start and maintain food production, so lack of supply,

selectie breeding

domestic dogs with a gentle nature,

sexual reproduction

• sperm and egg cells in animals

• pollen and egg cells in flowering plants

short sightedness,

concave lens in front of the eye, as the problem is that light is being focused in front of the retina f

fertilisation

zygote, maturę into an embryo, number of cells increase by mitosis, embryo develops so cell begins to differentiate, or specialise

embryo transplants

• sperm and egg cells from parents with desirable features are obtained

• lab, fertilised, to form an embryo

• embryo divides may times, then inserted into a host mother

• offspring born genetically identical

long sightednes

• light focused by lens behind the retina instead of onto it

• placing convex lens in front of the eye

plant, adaptations

• potions, nette, deadly night shade

• flowers, attract insects to pollinate them

gibberellins

plant hormone responsible for growth and development, low concentration only needed, increase fruit size,
- brewing industry, germination of barley seeds increased to make malt

ethene

ethene controls cell division and stimulates enzymes that result in fruit ripening

examples of asexual reproduction

• bacteria, production of spores by fungi

• some, strawberry, use runners,

• formation of tubers in potatoes

• bulbs in daffodils

19th century genetics

• late,

• behaviour of chromosomes during cell division was observed

20th century

• early, observed that chromosomes and Mendel’s units behaved in similar ways, led to idea the unit, now called genes, were located on chromosomes

• mid 20th, structure of DNA was determined and the mechanism of gene function was worked out

IUDS

• copper, kill sperm in the uterus and stop any fertiliser embryos implanting in the uterus lining, t shapes, inserted into the uterus

• plastic, progesterone, preventing the maturation and release of eggs, small risk of epotic pregnancy, put in by doctor, can cause irritation

land pollution

landfill, toxic chemicals

water pollution

sewage, fertiliser, toxic chemicals

cornea

curved surface bends and focuses light onto retina,

MRI

• magnetic resonance imagery scanner

• create image of the brain

• show which parts of the brain is affected by a tumour, which part is active during a specific task

electrical stimulation

• may result in mental or physical change, providing info on the role this area of the brain has

g.m crops

• resistant to pests, extreme weather conditions, increase yield

• increase nutritional value, good in placed they lack access to certain properties, golden rice, produce a chemical that converts in body to vitamin a

mutations

bacteria to produce insulin

• plasmid removed from a bacterium

• insulin gene cut out of a human chromosomes using a restriction enzyme

  • restriction enzyme recognise the specific sequences of DNA and cut the DNA at these points

• the cut leaves one of the DNA strands with unpaired bases, called a sticky end

• plasmid cut open using same restriction enzyme, leaving the same sticky end

• plasmid and human insulin mixed

• lipase added, joining the sticky ends together to produce recombinant DNA

• recombinant DNA instead into a bacterium and modified bacterium, then grow in a vat under controlled conditions, end with loads of bacteria that produce insulin

• taken and purified and harvested, to treat people with diabetes