Practice Exams 1 Flashcards
The enzymes that are required for the Krebs cycle in cellular respiration are found:
In the mitochondrial matrix
With respect ot the classification of ancestors and relative of modern humans it is true to say that:
Hominoids include gorillas, chimpanzees and Homo sapiens
Cells of the bacterium Pseudomonas fluorescens each have a flagellum that enables them to move. Removal of the master gene produced bacterium that did could not move. These bacteria were placed in a dish with a supply of food. Initially only the food immediately near the bacteria was consumed. After four days the bacteria were moving and almost all had flagella.
How do you explain these observations
Mutations in a gene enabled it to function as the master gene for flagella growth.
The specific 3-dimensional structure of a protein ultimately depends on the
Primary structure of the protein
As succinate dehydrogenase is involved in both the Kreb’s cycle and the electron transport chain it will therefore be found in the:
Inner membrane of the mitochondria
When apples are cut or damaged they become brown due to an enzymatic reaction involving the enzyme polyphenol oxidase (PPO). Scientists have developed an apple that does not brown by silencing genes involved in PPO production.They have used a genetic technique called RNA interferences (RNAi). RNAi is a natural process that cells use to silence the activity of a gene. The scientists introduced the appropriate RNAi into the plant using genetic engineering. The RNAi binds to the mRNA formed from the PPO gene. This silences the PPO expression to only 10%, which prevents the browning of the apple.
Is the new apple:
Transgenic?
Genetically Modified?
Transgenic = No
Genetically Modified = Yes
When apples are cut or damaged they become brown due to an enzymatic reaction involving the enzyme polyphenol oxidase (PPO). Scientists have developed an apple that does not brown by silencing genes involved in PPO production.They have used a genetic technique called RNA interferences (RNAi). RNAi is a natural process that cells use to silence the activity of a gene. The scientists introduced the appropriate RNAi into the plant using genetic engineering. The RNAi binds to the mRNA formed from the PPO gene. This silences the PPO expression to only 10%, which prevents the browning of the apple.
What is required for this technique?
The RNAi needs to have a nucleotide sequence complementary to the mRNA sequence that would be translated into the PPO enzyme.
When a naive B cell is activated by an antigen it first:
Undergoes clonal expansion followed by clonal selection.
Sometimes a break occurs in chromosomes and they then rejoin. One example is when the long arms of chromosomes 14 & 21 break and then fuse together with one centromere as shown in the diagram below.
This is an example of a:
Block mutation where the individual is phenotypically normal.
In the East African Lakes there exists a diversity of cichlid. The cichlids in Lake Tanganyika are genetically diverse coming from 11 ancestral species. Some cichlids left Lake Tanganyika and by entering the river system found their way to Lake Victoria and Lake Malawi.
Each lake has different species, but there are pairs of fish with similar body & jaw structures.
Cichlid fishes have evolved highly specialized modes of feeding through extensive adaptions of their jaws.
The similarity of the pairs of fish is an example of
Convergent evolution
When hominin fossil skeletons or parts thereof are found, scientists need to make careful observations to determine if they are of the genus Homo or of the genus Australopithecus.
Knowledge applied would be:
The feet of genus Homo are smaller with shorter toes.
