Answer:
The hominid pelvis displays many unique features (when compared to
that of quadrupedal primates) that support bipedalism. The major
adaptations are seen in the sacrum and the ilia, as well as in the
overall configuration and orientation of the pelvic bones.
Explanation:
These changes in the sacrum were for the adaption of standing on two legs,
The uniqueness is also that ilia are rotated and curved medially, bringing the lateral edge of the blade forward and projecting the top of the ilia outward laterally.
The right answer is B) gene.
A gene, in genetics, is a basic unit of heredity which in principle predetermines a specific trait of the form of a living organism, as defined in 1909 by Wilhelm Johannsen. From the physical point of view, a gene is a fragment of the determined locus of a DNA sequence.
A gene "parameter" the synthesis of a given RNA, by predefining its structure and, therefore, that of the possible protein or possible polypeptide synthesized from this RNA: this is what molecular biology studies .
These two aspects of the notion of gene are supposed to correspond, one at the physical and molecular level, the other at the level of principle and heredity.
Answer:
The environments in which cells grow often change rapidly. For example, cells may consume all of a particular food source and must utilize others. To survive in a changing world, cells evolved mechanisms for adjusting their biochemistry in response to signals indicating environmental change. The adjustments can take many forms, including changes in the activities of preexisting enzyme molecules, changes in the rates of synthesis of new enzyme molecules, and changes in membrane-transport processes.
Initially, the detection of environmental signals occurred inside cells. Chemicals that could pass into cells, either by diffusion through the cell membrane or by the action of transport proteins, and could bind directly to proteins inside the cell and modulate their activities.
Answer:
E. On in the presence of lactose and absence of glucose
Explanation:
Expression of lac operon synthesizes the enzymes required for catabolism of lactose sugar. When both glucose and lactose are available, glucose is preferred as a nutrient and the lac operon is not expressed.
Lac operon is expressed only when glucose is absent in the medium and lactose is present. If any of the two conditions deviate, the operon is not expressed.
In the absence of glucose and the presence of lactose, the repressor is rendered inactive to bind to the operator. RNA polymerase enzyme is free to bind to the promoter and continue the process of transcription.
The reduced levels of glucose increase the cAMP levels which in turn bind to the Catabolite activator protein (CAP). CAP is a positive regulator that binds to the promoter to facilitate the transcription of the operon by RNA polymerase.
Answer:
A) altering the nucleotide sequence of the DNA fragment
Explanation:
Gel electrophoresis is a technique to separate the DNA fragments on the basis of their charges and size. DNA fragments are made to migrate through a gel in an electric field. DNA has nucleotides and the presence of phosphate groups makes it a negatively charged molecule. In the gel electrophoresis, DNA fragment migrates through the gel toward the positive pole. Also, the gel slows down the large molecules more than the small molecules. Therefore, the DNA fragments are separated by size. However, the sequence of the nucleotide of DNA fragments does not affect the rate of their migration in the gel.
