Adaptation and inheritance Flashcards
(34 cards)
Who worked out how DNA was arranged and won the noble prize?
Watson and Crick
What are the features of DNA?
Two strands, form a double helix( twisted together in spiral), held together by bonds between base pairs (connects strands of DNA)
Who discovered DNA the photograph 51?
Rosalind Franklin
What is the smallest, Gene, chromosome or genome?
A gene.
Where are chromosomes found?
In the Nucleus.
How many chromosomes do normal body cells have?
23 pairs (46)
How many chromosomes do sperm and egg have?
23
What is a gene?
A section of DNA that gives us our characteristics.
What is a genome?
One copy of all our DNA.
How many genes do we have?
Around 20,000
Boys and girls belong to the same……
Species
What is one of the processes involved in selective breeding?
choosing individuals with desirable features. They can’t reproduce without interference.
Which of these is a common example of selective breeding?
Cows that produce lots of meat
Tomato plants that produce fewer tomatoes
Crops that catch diseases
A common example of selective breeding is cows that produce lots of meat. Farmers want lots of tomatoes not a few.
How have humans developed so many varieties of dog?
by selective breeding
What can all organisms of the same species do?
Reproduce to have fertile offspring
What is special about a liger?
A liger cannot reproduce.
What does infertile mean?
Cannot reproduce
Where is most variation found?
Most variation is found between species. Lions and tigers can reproduce to have ligers but this isn’t relevant here.
Which organisms all belong to the same species?
Dogs all belong to the same species. There are many species of shark.
What fertile?
Capable of producing offspring
What is selective breeding?
An artificial process in which organisms with desired characteristics are chosen as parents for the next generation
What is variation?
Difference between individuals; distance from the norm.
What is continuous variation?
Vary over large range of values
What is discontinuous variation?
Only have certain values
