Answer:
d. dilation of the blood vessels serving the skin and digestive viscera.
Explanation:
Cardiovascular effects of the sympathetic division include all of the following EXCEPT dilation of the blood vessels serving the skin and digestive viscera.
Answer:
It is the process where the plants use sunlight to gain their food.
Explanation:
Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
Hope this helps!
Answer:
Unlike the queen bee, which has 32 chromosomes, drones have half the chromosomal charge (n= 16), so they are considered haploid.
Explanation:
The system of determination of the sex in the bees —like in other insects— is called haplodiploidy, and consists of which the females of the species possess complete charge of chromosomes, whereas the males only possess half. This is what happens with the queen bee with 32 chromosomes, while drones only have 16 chromosomes, so they are considered haploid.
Additionally, as a characteristic of haplodiploidy, males only proceed from female gametes, so they can only contribute gametes to produce females of the species.
The other options are not correct because:
- <em>Drones, with half of the chromosomal charge, </em><u><em>cannot be diploid</em></u><em>.
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- <u><em>Monosomy and trisomy</em></u><em> are defects in the distribution of chromosomes during meiosis, which imply one chromosome less or one chromosome more in the normal chromosome charge respectively.</em>
Answer:
c. ¼ heavy, ¾ light
Explanation:
DNA replication follows semi conservative model which means that both the strands separate during replication and the newly formed DNA molecule has one old and one new strand. If instead of semi conservative, conservative mechanism is used, old strands will not separate from each other and the two newly synthesised DNA strands will come together to form a DNA molecule.
Here the cells were first grown in heavy 15N medium so all the DNA molecules had 15N and thus were heavy. Then the cells were transferred to 14N medium where only lighter 14N were available for replication process.
In first generation, 14N DNA molecules were synthesised from 15N DNA molecules so 1/2 DNA molecules were 15N and other half were 14N. In the second generation, 14N molecules will give rise to new 14N molecules and 15N molecules will also give rise to 14N molecules hence 1/4 molecules will be 15N (heavy) and 3/4 will be 14N (light).
