Introduction to Genetics. Why do biological relatives resemble one another?

Transcription

1 Introduction to Genetics Why do biological relatives resemble one another?

2 Heritage Hair color, eye color, height, and lots of other traits are passed down through families. How does that happen? REPRODUCTION & GENETICS

3 Asexual Reproduction: Natural Cloning Cell Cycle in Bacteria: Binary Fission Video

4 Asexual Reproduction: Natural Cloning Some animals can reproduce asexually Video Attached

5 Asexual Reproduction: Natural Cloning Plant Bulbs vs. Seeds Video Seeds (above) are produced by pollinators. Bulbs (left) are clones of the parent plant that spread underground. Bulbs are an example of asexual reproduction in plants.

6 Bacterial Conjugation: Not Sexual but Does Increase Genetic Diversity DNA is given to one bacteria from another through a bridge formed by a pili on the bacterial membrane.

7 Sexual Reproduction: Beneficial Increase of Genetic Diversity ½ like Mom and ½ like Dad = Completely Unique Remember that variation is good because it increases a species chance for survival. (You were a tree Did you survive? Why?) Video

8 Sexual Reproduction: Possible Due To The Production of Sex Cells Called Gametes Gametes such as sperm, egg, and pollen are HAPLOID meaning they contain HALF of the genetic material required for the organism.

9 Sexual Reproduction: Possible Due To The Production of Sex Cells Called Gametes 2 haploid cells join to create a DIPLOID cell through fertilization and create an offspring with a completely unique genetic make-up.

10 How Are Traits Passed Down? Gametes are HAPLOID (N) and carry one allele for each trait Zygotes are DIPLOID (2N) and carry two alleles for each trait, one allele from each parent. A child with White Forelock got a recessive allele from each parent. Her diploid genotype is ff. The egg and sperm each had a haploid genotype of f. *These are the same letter designations you used on Punnett squares last year.

11 Traits In Sexually Reproducing Organisms Can Be Traced Through A Pedigree Circle Female Square Male Colored In Has Trait Blank Does Not Have Trait Straight Line Mating Pair Line Down Offspring Bracket - Siblings

12 Sexual Reproduction in Non-Mammals

13 Nucleic Acids: Built of Nucleotides

14 DNA Structure: Phosphate, Sugar Deoxyribose, Nitrogen bases Thymine and Cytosine are Pyrimidines Adenine and Guanine are Purines

15 Chargaff s Rule Because A & T bind together in DNA, there is the same amount of adenine in the cell as thymine. Because C & G bind together in DNA, the same thing occurs.

16 DNA: What s Important? Nucleotide Sequence The more closely related two species are, the higher percentage of the DNA sequence that matches. The same is true for individuals within a single species.

17 RNA Structure: Sugar Ribose Uracil and Cytosine are Pyrimidines Adenine and Guanine are Purines

18 RNA: Single Stranded, 3 Types mrna: carries DNA nucleotide sequence (aka. Code) to the cytoplasm to be read rrna: part of the ribosome, the organelle that reads the code on the mrna to create proteins trna: transfers the code carried by the mrna into an amino acid sequence (aka protein) so that the information gets out to the cell

19 Unit Summary Reproduction can be sexual or asexual. Asexual reproduction is good because numbers increase quickly. Sexual reproduction is good because it increases genetic diversity by creating genetically unique individuals. Sexual reproduction includes gametes, which are haploid cells. Traits that are determined by genetics can be things that you can see (eye color) or things that you can t (immunities). DNA and RNA are nucleic acids which are built of nucleotides. DNA uses the sugar deoxyribose, the bases ATCG, is double stranded, and carries hereditary information from one generation to the next. RNA uses the sugar ribose, the bases AUCG, is single stranded, and comes in three forms that work together to read the code on the DNA sequence for the rest of the cell.