Answer:
a. There are different possible ways that homologous pairs might line up
c. Different alignments of homologous pairs will cause different combinations of alleles in gametes.
Explanation:
The law of independent assortment, proposed by Mendel, states that the alleles of one gene segregate into gametes independently of the alleles of another gene. This means that the segregation of one gene does not affect another. This law of independent assortment is evident during gamete formation in sexually-reproducing organisms know as meiosis. Specifically, in the Metaphase 1 stage of meiosis 1, homologous chromosomes (similar but non-identical chromosomes received from each parent) lines up at the metaphase plate (cell equator).
The lining up of chromosomes in this stage occurs randomly making it possible for chromosomes to align in different possible ways. The way/manner the chromosomes align at the equator determines which chromosome combination gets separated into which gamete. The homologous chromosomes are randomly distributed at the cell's equator before segregates into gametes. This random orientation enables the alleles of each gene on a chromosome to combine in different random ways, hence, allowing genetic diversity in the resulting gametes (sperm and egg) they get segregated into.
Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Answer:
<u><em>The correct option is C) genetic variation</em></u>
Explanation:
Genetic variation can be described as the differences present in the genetic material i.e DNA of organisms present in a population. Genetic diversity allows organisms of a species to better adapt to an environment. A population in which the genetic variability is scarce might become wiped out by a disease or an invading predator.
As the birds show different variations hence the term that best described them is genetic variation.
Answer: c) and b) are correct.
The brain is encased in a protective bony or cartilaginous housing in craniates.
The anterior end of the nerve cord is elaborated to form a brain in craniates.
Explanation: The craniates include the chordata with well-defined heads. This includes mammals, reptiles and fishes. So we can discard the other answers. Because most craniates have functional jaws, and the adults do not lose their chordate characteristics. The last one does not apply as a specific feature because the tunicate have neural crest but are not recognized as craniata.
Answer:
The correct answer will be option-B.
Explanation:
Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. The structure of DNA is made up of two strands of nucleotides coiled in a helical structure thus providing a double-helical shape to the structure.
Each nucleotide of a strand is composed of a five-carbon sugar, phosphate group and nitrogenous bases. These molecules are arranged in anti-parallel fashion in DNA which provides the polarity to the DNA strand. One strand is read from the 5' to 3' direction whereas another form 3'to 5' direction.
Thus, Option-B is the correct answer.
