biolagy Flashcards
what results in characteristic diversity?
differences in the DNA
what is DNA?
an extremely large molecule containing millions of atoms joined by chemical bonds
What is a double helix
A pair of separate strands of DNA twisted together
What is a ladder?
Drawing of a double helix DNA
What is each DNA strand made of?
repeated molecule units called nucleotides
how are DNA strands created?
when sugar and phosphate become two different nucleotides bonded together forming the backbone
what are the four different bases of DNA?
Adenine thymine cytosine gumine
What are the groups of two that the letters can bond together in?
AT and GC
what is replication?
The process of copying one DNA double helix into identical double helix is
What tells the cell what proteins to make
The genetic information in DNA
What does protein do?
Make the structure of the cells
What is protein synthesis?
The process of making protein from DNA
what is transcription?
DNA gets transcribed into messenger RNA which can leave the nucleus
how does transcription begin?
MRNA fines to ribosome made up of RRNA
what is protein made up of?
Many amino acids bonded together in a long chain
How are protein strands made?
when a TRNA that is floating around in the cell finds a con match on the mRNA it bonds and its amino acid is linked with a peptide bond that is growing protein
How are amino acids connected?
Buy a peptide bond
what happens in inter phase?
DNA exit a fibre called chromatic
what happens in mitosis or meiosis?
The cell divides to make two identical cells
what are the four steps of DNA becoming chromosome
A double helix, then looped onto a protein, then twisted into a coil and then packed into a chromosome
how many chromosomes does the human body have?
46
how many pairs of homologous chromosomes do we have?
23
what is a karyotype
A photograph of pairs of homologous chromosomes in a cell
How many genes are in the human DNA?
27,000
