The Next Generation, Carry On Chromosome And Its A Wonderful World Flashcards
What does sexual reproduction require?
Sexual reproduction requires two parents, production and fusion of gametes.
State two ways reproduction can occur
Sexual or asexual
What does sexual reproduction result in?
A variety of genetically different off spring
What does asexual reproduction require?
Asexual reproduction involves one parent, no gametes.
What variation is created in asexual reproduction?
No variation is created in all of the off spring. All off spring are genetically identical- a clone of the original parent
In what two ways can plants asexually reproduce. Give examples.
Runners.e.g. Spider plants, special stem
Tubers.e.g.potatoes, plants, hydra
If a cell has the full chromosome compliment. What is it known as?
Diploid. The cell has inherited half a set of chromosomes from female and other half from male.
What is meant by a haploid cell?
Haploid is the term used to describe a cell with only a single set of chromosomes single cells are known as gametes.
What is fertilisation?
Fertilisation is the fusion of the male gamete nucleus with the female gamete to form a zygote.
What is a zygote?
A fertilised egg.
What is the function of the uterus?
A fertilised egg implants here in the blood rich lining and develops into a baby
What is structure….
This is where sperm are released inside the female during sexual intercourse
Vagina
What is the structure
Protective folds of skin that cover the outside of the female reproductive system
Vulve ( labia)
What is meant by the ovary?
Eggs are produced her in a female body. The eggs are released approximately every month from puberty to menopause
What is the oviduct?
The tube that carries the egg from the ovary to the uterus. Fertilisation happens here.
What is the name of the ring of muscles at the top of the vagina that forms an entrance to the uterus.
Cervix
What is the clitoris?
A fleshy bump full of sensitive nerve endings
In the male reproductive system what is the function of the scrotum?
A sack of skin that holds the testes away from the body and keeps them at the ideal temperature for sperm production.
What is the name of the layer of skin that covers the sensitive head of the penis when it is not erect?
Foreskin
What is the glands?
A fluid added to sperm to make semen
What is the urethra?
The tube that runs down the centre of the penis to carry either sperm or urine
What is the name of the organ that fills with blood to become erect and is used to place super into the body of a female during intercourse?
Penis
What is the testicles function?
To produce male gametes (sperm)
What does the sperm tube do?
Carries sperm from the testes to the penis
What is the stages of fertilisation?
In mammals fertilisation happens in the oviduct. The zygote then starts to divide repeatedly as it travels down the oviduct into the uterus. An embryo the implants into the lining of the uterus where it will develop further.
Plants asexually reproduce. Define these terms. Sepals. Style Petals. Ovaries Carpel. Nectary Stigma
Sepals- protects flower when in bud
Petals- large and brightly coloured to attract insects
Carpel- female part of the flower
Stigma- often sticky, where pollen grains land during pollination
Style- the stalk between the stigma and the ovary, through which the pollen tube grows
Ovaries- contains ovules. (female gametes)
Nectary- makes a sugary liquid called nectar as a reward for insect pollinators
What is the stamen, and what is it made up of?
The stamen is the male part of the flower. It is made up of the anther( where pollen grains are made) and the filament ( a stalk which holds the anthers in place)
What is pollination?
Pollination is the transfer of pollen grains from the anther of one flower to the the stigma of another flower of the same species
What are two methods of pollination?
- carried out by insects/ animals
- carried out by wind
What are the three main parts of the seed?
Embryo, seed coat and food store
What is germination?
Germination is the process involved when a seed starts to grow
What does germination require?
- a suitable temperature. An optimum temperature for enzyme activity.
- oxygen for respiration to give energy to grow
- water. Enzymes require water to diffuses from the embryo into a food store.
What is homozygous?
The term used to describe an individual who carries identical alleles of a particular gene. This can also be known as true-breeding
What is a punnet square?
A diagram used to predict the possible genotypes of the offspring produced at a genetic cross
What is inheritance?
Inheritance is genetic information passed on to you by your parents. This genetic information is important because it determines an organisms characteristics.
Sometimes what alleles we predict is wrong. Why is that?
The observation and predicted ratios often do not match because fertilisation is a random process. There is a element of chance
What is genetic engineering?
The process of altering an organisms characteristics
In genetic engineering how can alternate an organisms characteristics?
- adding new genes ( may be from other species)
- removing or replacing undesirable genes e.g. Those that cause disease.
- increasing number of copies of a desirable gene already present
What are two ways in which genetic information can be transferred from one cell to another?
Naturally or genetic engineering
How can DNA be transferred?
Naturally by viruses or bacterial plasmids
What are the stages of genetic engineering?
- Identify the required gene in the source of the chromosome
- Extract the required gene using enzymes ( restriction)
- Insert the required gene into bacterial plasmids using enzymes (ligase)
- Insert modified plasmid into host cell
- Grow transformed cells to produce a genetically modified organism
Give examples of genetically modified plants
Golden rice, blight resistant potatoes and tomatoes with longer shelf life
What is the use of insulin?
Insulin is a hormone produced by genetically engineered bacterial for people with diabetes.
What is factor VIII
People with haemophilia cannot make this protein.itcan be produced by genetically engineered bacteria and given to haemophiliacs to restore the blood clotting process
What is human growth hormone?
It can be produced by genetically engineered bacteria and given by injection to treat children who do not produce themselves
What is an ecosystem made up of?
An ecosystem is made up of a community of living organisms and their habitats
What is a community
All the species living in a certain area
What is the population?
The number of organisms of one species
What is the habitat?
The place where the organisms are living
Where does the energy used by living organisms originally come from?
The sun
In a food chain what do the arrows represent?
The direction of energy transfer
At each energy transfer in a food chain, how much is typically LOST?
90%
Name the three main ways that energy can be ‘lost’ from a food chain
- heat energy
- movement (kinetic) energy
- in indigested materials
Name three types of pyramids
- pyramid of biomass
- pyramid of energy
- pyramid of numbers
What is a pyramid of biomass?
A diagram showing the total mass of living matter present in a food chain
What is a pyramid of energy?
A diagram that shows the total energy availability at each level of the food chain ( 10% passed on)
What is the pyramid of numbers?
The pyramid of numbers are blocks representing the number (population size) of organisms at each level. The bigger the block the greater the number
Why is a pyramid of energy better than pyramid of numbers
A pyramid of energy is better than a pyramid of numbers because it takes into consideration the volume of energy passed on
What is the food chain?
A food chain is a diagram showing the flow of energy between organisms through their feeding relation ship
What is a food web?
A food web is a complex diagram to show the intersections between many different food chains
What is a producer?
An organisms that makes its own food by photosynthesis. Producer. Plant. Photosynthesis
What is a consumer?
A organism which eats other organisms to obtain energy
What is competition?
The struggle for existence between members of a community that is caused by a limited supply of an essential source
What is it called when a resource is in short supply
A limiting factor
What is intra specific completion?
When individuals of the same species compete for the exact same resource
What is inter specific?
When individuals of different species compete for the same resource
What is a niche?
A niche is a role that an organism plays in its environment
What is biodiversity?
The term used to describe the range of species present within the community of an ecosystem
What are factors affecting biodiversity?
Abiotic and biotic
What are abiotic factors?
Abiotic factors are non-living things that which can have have an effect on a organism. E.g. Light intensity, pH. Soil moisture
What are biotic factors?
Biotic factors are living things in an environment which can effect an organism. E.g. Predators, disease and food availability
How can you measure abiotic factors?
Using a moisture meter, a pH meter and a light meter
Name a piece of a apparatus used to sample organisms. And name a source of error
You can sample organisms using a quadrat. A qudrat is a piece of apparatus divided into small squares. It is thrown at random and the number of boxes containing plants are counted. A source of error is getting to small a sample size.
How do you set up a pitfall trap? And what are possible sources of error
Dig a hole in soil. Insert plastic up. Create a natural loose lid and leave for 2 days. Sources of error include flooding.
How can you sample biodiversity?
- qudrats
- tree beating
- sweep netting
- pitfall trap
- pond clipping
What are biomes?
Biomes (climate regions) are the various regions of planet earth distinguished by there similar climate, flora and fauna
What are global distribution of biomes influenced by?
Abiotic factors. I.e. temperature and rainfall
What are decomposers?
The term used to describe organisms that get energy from breaking down dead bodies and waste materials
What are the main decomposers?
Bacteria and fungi.
What role do bacteria and fungi play in recycling nutrients?
They recycle nutrients such as carbon and nitrogen through the ecosystem
What are examples of nutrients recycled?
Nitrogen and carbon
What is nitrogen essential for?
Organisms producing protein
What is decay?
Decay is carried out by bacteria and fungi which break down dead bodies and waste material and release ammonia into the soil. This process in known as decomposition.
What are notifying bacteria?
Nitrifying bacteria are found in soil and are responsible for…
Ammonia > nitrites > nitrates
This process is known as nitrification
What are denitrifying bacteria?
Denitrifying bacteria are found in soil and are responsible for…..
Nitrates> nitrogen
This process is known as denitrification
What are nitrogen- fixing bacteria?
Nitrogen- fixing bacteria cave found in the soil and in the root nodules of leguminous plants. These bacteria convert …
Atmospheric nitrogen> nitrates
This process is called nitrogen fixation
What are leguminous plants?
This is a group of plants that have nodules other roots containing nitrifying bacteria. These plants can grown in nitrogen poor soils and are very important in crop rotation systems as they ass nitrate to the soil. Examples of these plants are clover, peas and beans
How can humans have an effect not the nitrogen cycle?
By harvesting, growing leguminous crops, adding natural fertilisers and chemical fertilisers
What are fertilisers used for?
Nitrogen based fertilisers are used to increase crop yields
What are chromosomes made of?
DNA
What are located in chromosomes?
Genes
What does DNA carry?
Genetic information and instructions to make proteins
What is a gene?
A section of a chromosome which controls one particular characteristic of an organism by coding for on protein
Where does a individual inherit a unique combination of genes?
Half from each parent
What is discrete variation?
Differences between individuals of the same species that can be placed in one of a definite number of a distinct group.e.g.sex, blood group
What is continuous variation?
Differences between individuals of the same species that fall within a range of measurements or values. E.g,hand span
What is polygenic inheritance?
The type of inheritance where a characteristic is controlled by several genes which interact with each other. E.g.height
Most characteristics are…..
Polygenic (affected by multiple genes, me show continuous variation
Some characteristics are controlled by a single gene. What characteristics are expressed in clear cut groups showing discrete variation?
Mono hybrid inheritance
What is a phenotype of an organism?
The phenotype is the expression of the genotype I.e how an organism looks with regards to a particular characteristic
What are alleles?
Alternative forms of the same gene
What forms can alleles be?
Dominant or recessive
What is meant by dominant?
The term used to describe the allele that is show in the phenotype of an organism even if it has only one copy of the allele
What is recessive?
The term used to describe the allele that is shown in the phenotype only if the organism has two copies of the alleles
What is genotype?
The genetic make up of an organism. Each individual carries two alleles of a particular gene
What is heterozygous?
The term used to describe an individual who carries two different alleles for a particular gene.
