Download presentation
Presentation is loading. Please wait.
Published byMary Dunlap Modified over 11 years ago
1
Genetics in the Cell cell membrane nucleus cytoplasm
2
In the nucleus of a cell:
chromosomes – made of many different genes genes – hold the genetic information for each trait All the body cells of humans have 46 chromosomes
3
meiosis is the process used to make gametes (sex cells)
gametes have ½ the # of chromosomes in the body cells Human gametes have 23 chromosomes
4
chromosomes in body cells chromosomes in gametes
organism chromosomes in body cells chromosomes in gametes human 23 46 78 39 chicken goldfish 104 52 ant 1 2 corn 20 10 Horsetail fern 210 105 butterfly 380 190 chimpanzee 48 24
5
chromosomes are made of supercoiled DNA
6
DNA (DeoxyriboNucleic Acid)
structure discovered in 1953 by James Watson and Francis Crick Watson, Crick and Maurice Wilkins won the Nobel Prize in 1962
9
DNA is shaped like a double helix (a twisted ladder)
sides – alternating molecules of sugar (deoxyribose) and phosphate
10
A T T A A T G C C G A T A T G C A T C G G C Adenine (A) Thymine (T)
rungs – four types of nitrogen bases: T A A T Adenine (A) G C always bond Thymine (T) C G A T Guanine (G) always bond A T Cytosine (C) G C A T C G G C
11
nitrogen bases are attached with hydrogen bonds
nitrogen bases attach to sugars (deoxyriboses) not phosphates nitrogen bases are attached with hydrogen bonds A -- T
12
DNA is made of units called nucleotides.
and so on… Each nucleotide has a sugar, a phosphate and a nitrogen base. (deoxyribose)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.