Genetics and Reproduction

Concepts

1) As shown in the Punnett square, the probability that the offspring of these two individuals will have dimples is 50% as there are two distinct genotypes.

2) Epistasis defines how the interaction of genes influences phenotypes. Modifier genes control the display of certain genes thereby modifying which phenotypes show (Mendelian genetics): a new one or a pre-defined one.

3) Within interphase, DNA is reproduced with continued protection around the nuclear membrane. During the second stage, prophase, the nuclear membrane is removed and DNA molecules create chromosomes. Thirdly, metaphase occurs when these chromosomes line up together at the central plane of the dividing cell (equatorial plate). In the anaphase, the chromosomes split; in telophase (step five), two distinct chromosomes are in place. Finally, cytokinesis occurs when two matching cells have an equal amount of chromosomes.

4) Messenger RNA transcribes the genetic code of DNA in protein synthesis.

5) An intron interrupts the protein code and gene sequence in DNA and RNA molecules.

6) In protein synthesis, the difference between transcription and translation should not be underemphasized. Transcription creates mRNA from DNA while translation creates amino acids from mRNA in the creation of proteins.

7) The advantages of internal fertilization include protection. Sperm and egg face no threats of external predators. This allows for economizing sperm and egg amounts since evolutionary adaptation does not overcompensate for an adequate amount of survivors. Finally, this method can also occur out of water environments.

8) The reproductive purpose of fruit is to protect and disseminate seeds contained within.

9) The benefits of sexual reproduction include increased genetic diversity and minimal defects.