B2.7 Flashcards
In plants and animals what are passed down
Characteristics
How would u present different characteristics
In a simple diagram
How are body cells divided
Mitosis
What do chromosomes contain
The genetic information
What happens during mitosis
Duplicate chromosomes Line up at centre Cell fibre pull them apart Membranes form around each chromosome Become nucleus Cytoplasm divides
What is mitosis used for
Growth or to produce replacement cells
How many sets of chromosomes do body cells have
2
How many sets of chromosomes do gametes have
One
What do cells in reproductive organs have to do to form gametes
Divide
What is meiosis
A type of cell division in which a cell divides to form gametes
Process of meiosis
Mitosis Pulled apart Pulled apart again Four gametes Each with a single set of chromosomes
What do gametes do at fertilisation
Join together and single body cell is formed
What is the difference between plant and animal differentiation
Animals differentiate at an early stage
Plants differentiate for life
What is cell division restricted to in mature animals
Repair and replacement
What can be differentiated into any human
Stem cells
What do we know if the reproduction process was asexual
Used mitosis
Why does sexual reproduction allow variation
Gametes fuse so one of each allele comes from each parent
How many pairs of chromosomes determine the gender of the child
1
What are the female sex chromosomes
XX
What are the male sex chromosomes
XY
What are some characteristics controlled by
A single gene
What is a dominant allele
Controls the development of a characteristics when it is present on only one of the chromosomes
What is recessive allele
Controls the development of q characteristics only if the dominant allele is not present
What is dna
Deoxyribonucleic acid- what chromosomes are made of in a double helix structure
What is a gene
Small section of dna
What is a gene code
A particular combination of amino acids which makes a specific protein
Everyone has unique dna expect
Identical twins
What is dna fingerprinting
Process to identify individuals, paternity test and forensic science
What are some diseases
Inherited
What is polydactyly
Extra fingers or toes caused by a dominant allele of gene and can only be passed by only one parent who has the disorder
What is cystic fibrosis
A disorder of cell membrane
How is cystic fibrosis inherited
Parents must be carriers or have the disease and caused by recessive allele
What can happen to embryos to show the allele that causes genetic disorders
Screened
What do genes do
They tell cells in what order to put amino acids together
What does DNA fingerprinting do scientifically
Cuts up a persons DNA into small sections and then separating them
What is mitosis
When a cell reproduces itself by splitting to form two identical offsprings
Advantages of stem cells
Cure diseases
Eradicate diseases
Disadvantages of stem cells
Embryos potential life
Curing patients are more important than embryos
What do genetic diagrams show
The possible combinations of gametes
What dis Mendel used
Pea plants
What conclusions did Mendel came to
Characteristics in plants are determined by hereditary units
Hereditary are passed on from both parents and one unit from each parent
Dominant allele is shown
What are alleles
Different versions of the same gene
How many alleles do gametes have
1
What so we call it when two alleles are the same
Homozygous
What do we call two different alleles
Heterozygous
What happens during ivf
Embryos are fertilised in a laboratory implanted into mothers womb
Why is more than one egg fertilised in ivf
More chance to be successful
How can cystic fibrosis be identified
IVF and embryo screening
Advantages of embryo screening
Help people suffering
Laws to stop going far
Treating disorders is too expensive
Disadvantages to embryo screening
Expensive
Could have been life if rejected
Desirable characteristics may be wanted
