DNA and inheritance Flashcards
(27 cards)
What do most cells have?
A nucleus
Where are all chromosomes found?
The nucleus of the cell
What is a chromosome?
Chromosomes are coiled up molecules called DNA
What is DNA?
A chemical made up of two long strands, arranged in a spiral.
What is a gene?
A gene is a short section of a chromosome
What do genes control?
Genes control many of our characteristics e.g hair colour, eye colour etc.
How do genes work?
genes work in pairs, one will be dominant over the other
How many chromosomes do humans have?
46 chromosomes
How many chromosomes do egg and sperm cells have?
23 each
What happens during reproduction?
How many matched pairs of chromosomes are there in normal cells?
23 pairs each
a) What happens during reproduction?
b)What does this mean?
a)the nucleus of the egg fuses with the nucleus of the sperm and becomes fertilised.
b)This means that the fertilised egg contains each of the chromosomes. It contains a copy of each gene
What do genes control?
characteristics ( something that makes you special)
What does the fertilised egg develops in to?
It develops into an embryo
What is heredity?
The process where genes are passed down from parent to child
Who were the first scientists to build a model of DNA?
Crick and Watson
Who were the other two scientists who helped them to understand the structure of DNA?
Wilkins and Franklin
What is the structure of DNA called?
Double Helix
What is a Double Helix?
A spiral made of two chains wrapped together
How did they figure out the structure of DNA?
Using X-ray
What does DNA stand for?
Deoxyribonucleic acid
What are the 4 bases for DNA?
A+T, C+ G
What is Lamarckism, Darwin’s theory of natural selection?
the theory of inheritance of acquired characteristics
What is natural selection?
A mechanism of evolution
The discovery of DNA
DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher
