Living Environment Translated English 2014 | Page 18

17.Meiosis- a type of cell division which produces four sex cells
with ½ the original chromosome number of the mother cell.
18.Sperm- male sex cell ( haploid)
19.Egg- female sex cell ( haploid)
20.Fertilization- the joining of an egg and a sperm cell to form a
fertilized egg ( zygote). Restores the original chromosome
number
21.Zygote- a fertilized egg ( diploid)
22.Diploid- the normal chromosome number
23.Haploid- ½ of the normal chromosome number
24.DNA-( deoxyribonucleic acid) the genetic material of all
organisms; made up of two twisted strands of sugarphosphate molecules and nitrogen bases
25.Double helix- the structure of a DNA molecule
26.Gene- a section of DNA on a chromosome that contains
instructions for making specific proteins
27.Watson and Crick- two scientists who discovered the
structure of the DNA molecule
28.Transcription- the process in which messenger RNA copies
the code for a protein from DNA
29.Translation- the process that occurs at the ribosome when rRNA reads the code for a protein from messenger RNA and
builds the protein
30.RNA- ( ribonucleic acid)- a type of nucleic acid that carries
codes for making proteins from the nucleus to the ribsomes
31.Messenger RNA- form of RNA that carries genetic information
from the nucleus to the cytoplasm
32.Transfer RNA- form of RNA that brings amino acids to
ribosomes during protein synthesis
33.Ribosomal RNA- RNA that is in the ribosome and guides the
translation of messenger RNA into a protein
34.Adenine- a nitrogen base found in both DNA and RNA
35.Thymine- a nitrogen base found only in DNA