MODULE 5: Heredity Flashcards
Identify and Compare two types of protein
Structural Proteins: provide support for cells as it form the basis of the cytoskeleton, organelles and major structures (macro-molecular structures: hair, nails etc)
Functional Proteins: involved in biochemical reactions (function as enzymes
DNA Profiling
Polymorphisms are called short tandems of DNA are specific regions of DNA that vary highly between people. Each DNA fragment (line) is highly specific and can be used to determine such relationships.
Justify why external fertilisation can be more advantageous then external fertilisation in ensuring the continuity of a species
For the continuity of a species, each generation must successfully reproduce to produce sufficient numbers of the next generation.
A critical number of embryos must survive to gestational maturity. This is less likely with external fertilisation. Organisms that reproduce by external reproduction spend a substantial amount of energy and resources in the production and release of very large numbers of sperm and eggs. This is because each sperm and egg and the resulting embryos have limited chances of survival, not being protected by the parent for example in the open ocean. Chances of successful fertilisation are low in such vast aquatic environments. Larger numbers ensure some will be fertilised. Internal fertilisation provides a smaller safer environment for release of gametes, fertilisation and maturation of the embryos. Chances of successful fertilisation are increased and embryos are protected from predators within the body of the parent. Even after birth/egg laying parental care assists survival of the offspring.
-genetic variability, evolutionary fitness
Describe the role and changes in levels of a hormone in pregnancy.
A hormone that is important in pregnancy is progesterone. Progesterone is initially produced by the corpus luteum in the ovary and causes the endometrium to thicken, which helps to support and maintain the pregnancy in the first weeks when the placenta is still developing. The developed placenta then produces progesterone at significantly higher levels to maintain the pregnancy. Prior to birth progesterone levels drop significantly to facilitate labour.
How does the segregation of chromosomes during meiosis lead to a wide variety of gametes being produced?
In meiosis, there is a reduction division. Chromosome pairs line up together and one of each pair goes into the daughter cells. For each pair, this process is independent – hence a large number of combinations is possible.
