Answer:
DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.
A Cleavage Furrow forms between the two plant cells.
Answer:
The parent's genotypes are:
Ddpp - tall, white parent
ddPp - dwarf, purple parent.
Explanation:
This question involves two different genes coding for height and flower color in pea plants. The alleles for tallness (D) and purple color (P) are dominant over the alleles for dwarfness (d) and white color (p) respectively.
According to this question, a tall plant with white flowers is crossed with a dwarf plant with purple flowers to produce the following proportion of offsprings: 1/4 tall purple, 1/4 tall white, 1/4 dwarf purple, and 1/4 dwarf white.
Since some of the offsprings contain recessive alleles for both or either genes, the dominant traits of the parent is controlled by an heterozygous genotype. This means that the tall plant with white flowers has a genotype: Ddpp while the dwarf plant with purple flowers has the genotype: ddPp. In a cross between Ddpp × ddPp, 1/4 of each combination of alleles is produced in the offsprings (see punnet square in the attachment).
Answer:
Option-B
Explanation:
The brain is an organ composed of neurons which controls all the voluntary and involuntary of animals. In humans, the brain is located in the skull where the brain is suspended in a fluid called cerebrospinal fluid.
As humans ages and becomes old aged, the neurons in the brain losing their ability to perform their function, if they are lost they cannot be regenerated.
The lesions appear on the white matter of the brain and the brain shrink. Due to these known and other unknown features, the process controlled by these neurons become inadequate and shows slower brain processing and weak memory.
Thus, Option-B is the correct answer.
The autonomic nervous system<span> plays an essential </span>role<span> in </span>keeping the body'sinternal environment (temperature, salt concentration, blood sugar, oxygen and carbon dioxide level in blood, etc) in proper balance, a condition calledhomeostasis<span>. ... These and other </span>body<span> actions are controlled by the autonomic</span>nervous system<span>.
Hope this helps :)</span>
