Genetics And Inheritance Flashcards
What is the the function of a cell membrane?
controls what enters and leaves the cell
What is the the function of the nucleus?
contains the DNA (chromosomes)
What is chromosome?
a strand/piece of DNA
What is the function of cytoplasm?
Where chemical reactions take place
What is the function of mitochondria?
where respiration occurs
What is the function of ribosomes?
site of protein synthesis in the cell
What is the function of the cell wall?
supports the structure of the cell
What is the function of chloroplasts?
Contains chlorophyll which is needed for photosynthesis
What is the function of the permanent vacuole?
Filled with cell sap to help keep the cell turgid (swollen and hard)
Where is DNA found?
inside the nucleus
What does DNA stand for?
Deoxyribonucleic acid
What is variation?
The difference between individuals of the same species
What are the 2 types of variation?
Genetic and Environmental
What is DNA?
the chemical molecule in the nucleus that carries our genetic code
What is the role of DNA?
it codes for our characteristics. eg. eye colour
How is DNA arranged?
strands called chromosomes
How much chromosomes does a normal human body cell have?
46
How much chromosomes do human sex cells have?
23
Genetic material is stored in the __________ of all cells. This material is called __________. It contains information needed to make an organism
Nucleus, DNA
DNA is arranged into strands called ______________.
chromosomes
You have ___ chromosomes in each cell, arranged into 23 ____
46, pairs
Half the chromosomes come from ____ and half from ____
mum, dad
What is it when the egg cell and sperm cell fuse?
fertilisation
What is a zygote?
a cell formed by fertilization
What is an embryo?
The initial stage of development of an organism
What is a gene?
A section of a chromosome that codes for a particular characteristic
What is chromosome?
A threadlike structure made up of protein and a single molecule of DNA.
What is an allele?
We inherit two forms of genes (one from mum and one from dad). Each form of gene is called an allele.
What is a dominant allele?
Expressed even if only one of the alleles is dominant. eg. BB or Bb
What is a recessive allele?
Expressed only if there are 2 recessive alleles. eg. bb
What are homozygous alleles?
When an individual has 2 identical alleles. eg. TT, tt
What are heterozygous alleles?
When an individual has 2 different alleles. eg Tt
What is a genotype?
Describes the the alleles of an individual. eg. BB, Tt, ss
What is a phenotype?
Describes the physical appearance of an individual. eg. brown eyes, tall, curly hair
What is nature vs nurture?
A debate between the influence of genetics (nature) and social environments (nurture) on the development of individual and which one is more dominant
What chromosomes does a male have?
XY
What chromosomes does a female have?
XX
Is a dominant allele represented by a lowercase of capital letter?
capital
Is a recessive allele represented by a lowercase of capital letter?
lowercase
What is a gamete?
A reproductive/sex cell. The female sex cell is the egg cell and the male sex sell is the sperm cell
What are the two types of sperm cell?
X and Y
What are the two types of egg cell?
X and X
Is cystic fibrosis a dominant or recessive gene ?
recessive
Is polydactyl a dominant or recessive gene?
dominant
What is cystic fibrosis?
-a disorder of cell membranes
-caused by a defective gene inherited from parents
-lungs produce a thick mucus that leads to blockages in air passages and chest infections
-mucus also occurs in pancreas which causes digestive problems
-you need two recessive alleles to get it
What is polydactyl?
-a genetic disorder of the 7th chromosome
-results in extra fingers or toes
-means extra digits
-you only need one dominant allele in order to get it
What is screening?
testing people for the presence of a particular allele or other genetic abnormality
What is selective breeding?
Changing the characteristics of animals or plants by selecting which members of a species you want to breed
What is the process of selective breeding?
-select 2 parents who show high levels of a characteristic you want
-breed them
-select the offspring that shows high levels of the desired characteristic
-repeat this for many generations until the offspring shows high levels of the desired characteristic
What is selective breeding also known as?
Artificial breeding
What are the advantages to selective breeding?
-higher economic gains
-eliminating disease
-creates new varieties of crops
-does not involve genetic modification
-produces fitter stronger animals
-can change the evolution of a species
What are the disadvantages to selective breeding?
-animal discomfort
-loss of variety and variation (inbreeding)
-no control of genetic mutations
-lower gene pool
What is genetic engineering?
A process that involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic
What is a genome?
the 23 pairs of chromosomes located in the cell’s nucleus
What are GM crops
Genetically modified crops. Crops that have been through genetic engineering
What are the advantages of genetic engineering?
-manufacturing insulin
-crops produce greater yield
-finding out where genes are expressed in the body
-crops resistant to disease and pests
-improving diet in developing countries
-it only takes 1 generation
What are the disadvantages of genetic engineering?
-the plant/animal can breed with wild plants/animals
-people don’t know the long term effects
-people feel that it is unethical
How is insulin manufactured?
-DNA taken from a human cell
-use an enzyme to cut/isolate the required gene from the DNA
-use a different enzyme to cut the plasmid of a bacterial cell
-use an enzyme to cut a section of DNA from the plasmid insert the gene for insulin into the plasmid
-use another enzyme to join the ends of the DNA
-put the plasmid with the insulin gene back into a bacterial cell
-leave the bacteria to divide
-insulin is removed and purified
-it is ready to use
What is cloning?
making a genetically identical copy of an individual
Which is easier to clone: mammals or plants?
plants
What is the process of cloning?
-take a normal body cell from the organism to be cloned and keep the nucleus
-take an egg cell from another organism and remove the nucleus (and discard it)
-insert the nucleus of the normal body cell into the empty egg cell
-electric shock is given to simulate cell division
-implant the embryo into the uterus of a surrogate organism to develop a clone
There are ethical arguments for and against human cloning. What reasons could be used to argue for human cloning?
-produces valuable tissues and organs that could be used to save peoples lives
-could cure diseases
-help those who are infertile
-could help the medical research into diseases
There are ethical arguments for and against human cloning. What reasons could be used to argue against human cloning?
-may produce more diseases in the natural world
-shows no respect for human life
-human life will be no longer unique
-playing God
-deformed failure clones
Organize the parts of a nucleus from largest to smallest
-nucleus
-chromosomes
-DNA
-genes
