<h2>Scurvy </h2>
Explanation:
(a) Collagen is the major structural component of cartilage,bones and tendons
- The basic unit of collagen is tropocollagen and each tropocollagen consists of three coiled left handed polypeptide chains called α chains
- Generally each α chain consists of a repeating tripeptide sequence called: G-X-Y
- Here G represents glycine; X represents proline and Y represents hydroxyproline
- Rigidity of collagen molecule is due to presence of proline and hydroxyproline
- Hydroxylation of proline is catalysed by prolyl hydroxylase enzyme which use ascorbate,α ketoglutarate and oxygen
- α ketoglutarate is oxidatively decarboxylated to form carbon dioxide and succinate
- Sequence of events leading from a dietary vitamin C deficiency to symptoms such as bruising and breakdown of supporting tissues includes: tissue levels of ascorbic acid is low; enzyme prolyl hydroxylase is inactive; proline is not hydroxylated; the triple helix is inadequately stabilized; collagen breaks down; defects in tissues that depend on collagen
; tissues that depend on collagen are subject to breakdown and bruising
(b) Sailors are no longer susceptible to scurvy because fresh fruits which are the source of vitamin C source are available now
British sailors called "limeys" to this day,this term reflects the British navy's use of limes
Answer:
Dominant genes mask recessive genes.
Explanation:
Alleles are different variations of a gene. Every person has two alleles - one from each of their parents. Depending on whether it is expressed, an allele can be dominant or recessive.
A dominant allele is the one that is expressed even if the individual has one dominant and one recessive allele. This means that dominant alleles mask recessive alleles.
An example of a dominant allele is the one for brown eyes. This means that you need only one allele of this type to have brown eyes, which is why brown eyes are the most common.
Answer:
Mold fossils A fossilized impression made in the substrate; a negative image of the organism.
Cast fossils Formed when a mold is filled in.
Trace fossils or Ichnofossils Fossilized nests, gastroliths, burrows, footprints, etc.
True form fossils Fossils of the actual animal or animal part.
The correct answer is B, I know this because none of the other answers are even reasonable. For example-
A is wrong because the size of elephant tusk has not changed over time, elephant tusk just grow...
C is wrong because it makes no sense to hunt elephants with no tusk :/
D is completely wrong because tusk have nothing to do with reproduction, those are two completely separate bodily functions.........
