chapter 4 heredity and evolution. dna dna is found in the nucleus of cells, organized into single-...
TRANSCRIPT
![Page 1: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/1.jpg)
Chapter 4
Heredity and Evolution
![Page 2: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/2.jpg)
DNA DNA is found in the
nucleus of cells, organized into single-stranded chromosomes, and tells the cell how to function and what type of cell it’s supposed to be (i.e. liver cell, hair cell, skin cell, bone cell, etc.)
DNA is made of nucleotides (a sugar, a phosphate and one of four nitrogenous bases)
Review…
![Page 3: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/3.jpg)
How DNA gets copied
RibosomesRibosomes
NucleusNucleus
DNADNA
Review…
Every cell must contain the genetic information and the DNA is therefore duplicated before a cell divides (replication)
After the DNA replicates inside the cell’s nucleus, it must get it’s message outside the nucleus…
…through the goopy cytoplasm of the cell…
…and into the Ribosomes! RNA
CytoplasmCytoplasm
![Page 4: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/4.jpg)
A chromosome is composed of a DNA molecule and associated proteins.
A gene is the entire sequence of DNA bases responsible for the synthesis of a protein.
Genes and ChromosomesReview…
![Page 5: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/5.jpg)
Exons are the only parts of genes that are expressed in an individual.
People also have Introns in their genes, copied faithfully copied by the mRNA that are later clipped out and not expressed for some reason not yet known.
GenesReview…
![Page 6: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/6.jpg)
Chromosome Structure During normal cell
functions, chromosomes exist as single-stranded structures.
During cell division, chromosomes consist of two strands of DNA joined at the centromere.
Since the DNA molecules have replicated, one strand of a chromosome is an exact copy of the other.
Review…
![Page 7: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/7.jpg)
Mitosis Mitosis is cell division in somatic cells. Mitosis occurs during growth and
repair/replacement of tissues. The result of mitosis is two identical
daughter cells that are genetically identical to the original cell.
Here’s the steps…
Review…
![Page 8: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/8.jpg)
Mitosis The cell is involved in
metabolic activities. DNA replication
occurs, but chromosomes are not visible.
Review…
![Page 9: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/9.jpg)
Mitosis The nuclear
membrane disappears, and double-stranded chromosomes are visible.
Review…
![Page 10: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/10.jpg)
Mitosis The chromosomes
align themselves at the center of the cell.
Review…
![Page 11: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/11.jpg)
Mitosis The
chromosomes split at the centromere, and the strands separate and move to opposite ends of the dividing cell.
Review…
![Page 12: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/12.jpg)
Mitosis The cell membrane
pinches in as the cell continues to divide.
The chromosomes begin to uncoil (below).
Review…
![Page 13: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/13.jpg)
Mitosis After mitosis is
complete, there are two identical daughter cells.
The nuclear membrane is present, and chromosomes are no longer visible.
Review…
![Page 14: Chapter 4 Heredity and Evolution. DNA DNA is found in the nucleus of cells, organized into single- stranded chromosomes, and tells the cell how to function](https://reader030.vdocument.in/reader030/viewer/2022032805/56649efa5503460f94c0cec8/html5/thumbnails/14.jpg)
Meiosis Cell division in
specialized cells in ovaries and testes.
Meiosis involves two divisions and results in four daughter cells, each containing only half the original number of chromosomes.
These cells can develop into gametes.
Review…