Answer:
Seven other species are extinct, prehistoric species known from fossils. The giraffe's chief distinguishing characteristics are its extremely long neck and legs, its horn-like ossicones, and its distinctive coat patterns. It is classified under the family Giraffidae, along with its closest extant relative, the okapi.
Answer:
The answer is D
Explanation:
Fiber cells; cylinder-shaped
Answer:
Natural selection causes change in allele frequencies within a population.
So option A is correct one.
Explanation:
Natural selection generally work on an organism’s phenotype, or observable features. Phenotype is often largely a product of genotype (the alleles, or gene versions, the organism carries). When a phenotype produced by certain alleles helps organisms survive and reproduce better than their peers, natural selection can increase the frequency of the helpful alleles from one generation to the next – that is, it can cause microevolution.
Answer:
B) nuclei of gland cells.
Explanation:
DNA carries the blueprint for the production of all the proteins including enzymes in human beings. Humans are eukaryotes and their DNA is present in the nucleus of their cells. All the cells that make the complex human body are derived from division in the zygote and therefore, are genetically identical and have the same DNA.
However, gene expression is regulated by the expression of specific genes in specific cells and at a different time of developmental stages. Amylase is the enzyme that digests starch in humans. Amylase is secreted by salivary glands. So, the nuclei of these glands would have genetic information for the synthesis of amylase.
