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