Inheritance, variation and evolution Flashcards
What is DNA?
The chemical that all of the genetic material in a cell is made up from.
What does DNA stand for?
Deoxyribonucleic acid 
What are the long structures of DNA called?
Chromosomes
Where is DNA found?
nucleus
In what numbers do chromosomes usually come in?
Pairs
What is the shape of DNA?
Double helix
What is a gene?
A small section of DNA found in a chromosome
What does genes do?
they code for a particular sequence of amino acids, which are put together to make specific protein
Name a type of protein that cells produce?
haemoglobin
What does a proteins made from amino acids (from gene coding) determine?
What kind of cell it is
What is a Genome?
Is the term for the entire set of genetic material in an organism
why is the study of the human Genome important?
it allows scientists to identify genes that are linked to different types of disease, which could help them be cured, it also helps trace things like migration which tell us where ancestors come from.
What is sexual reproduction?
reproduction where genetic information from two organisms are combined to produce offspring are genetically different to either parent.
What is meiosis?
Sexual reproduction
In human cells how many chromosomes do each gamete have?
23
What are gametes?
Sex cells
What does sexual reproduction involve?
The fusion of male and female gametes. Because there are two parents. The offspring contain a mixture of the parents genes
Flowers have a egg cells but what is their version of sperm?
Pollen
What kind of cells does asexual reproduction produce?
Genetically identical cells
Why, in a sexual reproduction, are the offspring genetically identical?
Because there is only one parent and not a mixture of genetic information
what is the process of asexual reproduction called?
Mitosis
Why are there only 23 chromosomes in a gamete?
so that when they fuse the numbers add together to make a full set. 
What happens before a cell can divide?
duplicates it’s genetic information, forming to armed chromomes, Each arm is an exact copy of the other arm. Are you going to arrange themselves into pairs.
The chromosome pairs in line up in the centre of the cell so that they can be pulled apart so each new cell only has one copy of each chromosome. 
In the second division, the chromosomes lineup against the centre of the cell in the arms are pulled apart.
What happens after a gamete fusion happens?
The newly formed cell will divide by mitosis to make a copy of itself, then mitosis repeats many times to produce lots of new cells in an embryo. When the embryo develops the cells start to differentiate into different types of specialised cells to make a whole organism
How many pairs of chromosomes are there in every human cell?
23
What are the 23rd pair of chromosomes?
The XX or XY chromosome
what does the XX or XY chromosome decide?
It decides your sex
What chromosomes define males and which one defines females?
Males have the XY chromosome and females have The xx chromosome
which of the X and Y chromosomes are bigger?
The X chromosome
What do genetic diagrams to?
show the possible combinations of gametes?
Name a type of genetic diagram?
Punnet square
What is an allele?
Different versions of a gene
How many alleles of every gene are there in your body
Two
What is it called when the two alleles for a particular gene are the same?
Homozygous
What is the name for two alleles for a particular gene or different?
Hey
When two alleles are different, only one can determine the characteristic present. What is the name of the characteristic that shown in the one that isn’t?
Don’t show it is the dominant allele and the one that isn’t is the recessive
What does an organism have to have for recessive characteristic to should be shown?
both its alleles must be recessive.
What is your phenotype?
The physical features of your characteristic shown
what kind of allele is cystic fibrosis caused by?
Recessive
What kind of allele is polydactyly caused by?
Dominant
What is in vitro fertilisation (IVF) ?
Where embryos or fertilise an alarm for tree, and then implanted into a mother’s womb
What is embryo screening?
When before implantation, it’s possible to remove a cell each embryo and analyse its genes. Many genetic disorders can be detected this way, it’s also possible to look at the DNA.
Why might somebody disagree with embryo screening?
because bad alleles can be destroyed, it could also lead to a termination of pregnancy.
What are some reasons in favour of embryo screening?
It might help stop people from suffering, treating disorders cost lots of money, there are laws to stop it going too far.
