Genetics Flashcards
What is DNA made up of?
Nucleotides
What do Nucleotides consist of?
A sugar molecule, phosphate molecule and one ‘base’
What do the sugar and phosphate molecules form?
A backbone
What are the 4 different bases?
A denine
T hymine
C ytosine
G uanine
What is the shape of a DNA molecule?
2 strands coiled together in shape of a double helix.
What are the complementary base pairs joined together by?
Weak hydrogen bonds
What is DNA stored as?
Chromosomes
What does DNA contain?
Genes
What are Chromosomes?
Long, coiled up molecules of DNA.
found in the nucleus of eukaryotic cells
What is a Gene?
A section of DNA on a chromosome that codes for a particular protein
What can you use genetic diagrams for?
Predict how different characteristics will be inherited
What is Sexual Reproduction?
Where genetic information from two organisms is combined to produce offspring which are genetically different to either parent.
In sexual reproduction, what do the father and mother produce?
Gametes (sex cells)
What are the Gametes in animals called?
Sperm and Egg cells
How much Chromosomes do Gametes have? And what are they called?
Only contain half the number of chromosomes of normal cells. Called Haploid.
What are Normal cells with full number of chromosomes called?
Diploid.
What happens at fertilisation?
A male gamete fuses with a female gamete to produce a fertilised egg.
What is another word for a fertilised egg?
Zygote.
Is the Zygote a haploid or diploid?
Diploid.
What happens to the Zygote after fertilisation?
It undergoes cell division and develops into an Embryo.
What does the Embryo do?
Inherits characteristics from both parents, as it has received a mixture of chromosomes from its mother and father.
What is Meiosis?
A type of cell division. It’s different to mitosis because it doesn’t produce identical cells.
What happens before the cell starts to divide? (Meiosis)
It duplicates its DNA. One arm of each X-shaped chromosome is an exact copy of the other arm.
What happens in the first division of Meiosis?
The chromosomes line up in pairs in the centre of the cell. One came from the Mother and One from the Father.
The pairs are then pulled apart, so each new cell only has one copy of each chromosome. Some of the father’s chromosomes and some of the mother’s chromosomes go into each new cell.
