Answer:
3rd generation = 2 Hybrid DNA molecules + 6 Light DNA
In Percentage 2÷8 × 100 = 25%
25% of the DNA are hybrid
Explanation:
Semi conservative model proposed by Watson and Crick states that one strand of the DNA comes from parent DNA which act as a template for the other newly formed strand.
First generation:
If cells containing 15 N DNA are transferred to a medium with only 14 N then in initial first generation two parent strands becomes separated and act as template for newly synthesized strands. this means that in first generation both DNA molecules are hybrid, one strand of 15 N DNA and other strand of 14 N DNA
Ist generation = 2 Hybrid DNA molecules
Second generation:
In Second generation these two hybrid molecules become unzip. Two strands are 15N and two strands are 14N. All these 4 strands act as template and 4 new strands are synthesized. The molecules of Hybrid DNA is still 2 with 2 molecules of Light DNA.
2nd generation = 2 Hybrid DNA molecules + 2 Light DNA
Third generation:
In Third generation these two hybrid molecules and two light DNA molecules become unzip. Two strands are of 15N and six strands are of 14N. All these 8 strands act as template and 8 new strands are synthesized. The molecules of Hybrid DNA is still 2 with 6 molecules of Light DNA.
3rd generation = 2 Hybrid DNA molecules + 6 Light DNA
In Percentage 2÷8 × 100 = 25%
25% of the DNA are hybrid
B. xylem and phloem. they transport water and nutrients throughout the plant
Answer:
So that each cell has a full copy of DNA
Explanation:
Answer:
a. midbrain
b. thalamus; hypothalamus, epithalamus
c. cerebral aqueduct
d. medulla oblongata
e. choroid plexus
f. pons; medulla oblongata; midbrain
g. hypothalamus
h. cerebrum
i. epithalamus
j. cerebrum
k. cerebellum
Explanation:
The brainstem is the posterior part of the brain that connects the cerebrum with the spinal cord. The brainstem can be divided into three parts: midbrain (i.e., mesencephalon), the pons (i.e., metencephalon), and the medulla oblongata (i.e., myelencephalon). The mesencephalon is a region of the brain composed of the tectum and tegmentum, which play fundamental roles in motor movement, auditory and visual processing. The corpora quadrigemina is found at the tectum region of the midbrain. The diencephalon is a small part of the brain located above the brainstem (between cerebral hemispheres); which contains the thalamus, hypothalamus, subthalamus, and epithalamus. In turn, the epithalamus is composed of the habenular nuclei, pineal gland, and the stria medullaris thalami. The cerebral aqueduct is a narrow channel (approx. 15 mm) in which the cerebrospinal fluid flows between the third ventricle and the fourth ventricle. The medulla oblongata is a long stem-like structure located in the brainstem of the brain, just in the place where the brainstem connects the brain to the spinal cord. The choroid plexus is a complex network of capillaries located at the cerebral ventricles of the brain, which serve to produce cerebrospinal fluid through ependymal cells that line the ventricles of the brain. The cerebellum is a major structure of the hindbrain and consists of the cerebellar cortex and a core of white matter having the cerebellar nuclei.
