Answer:
The principal components of the plasma membrane are lipids (phospholipids and cholesterol), proteins, and carbohydrate groups that are attached to some of the lipids and proteins.
It is probably the l<span>amellae.
The lamellae are sheets of bony matrix. This bony matrix is produced by o</span>steoblasts, which are cells that synthesise collagen<span> and specialised proteins like </span>osteocalcin<span> and </span>osteopontin. These are then the most important constituents of the bony matrix.
The possible genotypes for someone who can roll their tongue are RR or rr, where the R allele is dominant over the r allele.
<h3>What do you mean by Genotypes?</h3>
Genotypes may be defined as the ultimate combination of alleles of those genes which are selected for a particular study or interest.
If R represents the dominant allele and a person rolls their tongue having this allele, while the r represents the recessive allele and a person can not roll their tongue having this allele. To roll their tongue, a person needs only one dominant allele. Thus the person could have genotypes of RR or Rr.
Therefore, the possible genotypes for someone who can roll their tongue are RR or rr, where the R allele is dominant over the r allele.
To learn more about Mendelian Genetics, refer to the link:
brainly.com/question/2240360
The only option given above that is true for natural selection to occur is option d: 'there must be competition for resources'. Natural selection would also occur under predatory pressure. Natural selection occurs through individuals with advantageous characteristics (phenotypes) surviving and passing on their genes (genotypes) to their offspring.
