C. Protective over young cubs
Insect populations can develop resistance to insecticides over time. The evolution of resistance is associated with an increase in the frequency of adaptive genes in the population.
- In the case above described it is expected that a few mosquitoes in the population were resistant to DDT before it was ever used (Option a is correct).
- Dichlorodiphenyltrichloroethane (DDT) is a pesticide used in agriculture.
- After exposure to DDT, those individuals in the mosquito population that didn't carry gene variants (i.e., alleles) associated with the resistance to this pesticide died.
- Subsequently, insects having adaptive alleles associated with DDT resistance survived and reproduced, thereby increasing the frequency of adaptive genes/alleles in the population.
Learn more in:
brainly.com/question/6389591?referrer=searchResults
The answer is d. chromosomes help an organism produce usable energy
Within a gymnosperm megasporangium, the following developmental sequences that are correct, assuming fertilization occurs is: megaspore, female gametophyte, egg cell, sporophyte embryo. The last Option (Option D) is correct.
In gymnosperm megasporangium, the meiotic division produces four haploid megaspores from a single cell, three of which generally degenerate. The female gametophyte is formed by mitosis from the surviving megaspore.
Prior to fertilization, the male mature gametophyte needs to be transferred to the female gametophyte for fertilization to take place.
When the nuclei of the sperm encounter the nucleus of the egg cell in gymnosperms, it fuses with the egg nucleus to produce a diploid zygote.
Mitosis occurs in the fertilized egg to initiate the growth of a new sporophyte generation (the multicellular embryo of the seed.)
Therefore, we can conclude that we've understood the mechanism of developmental sequence in the gymnosperm megasporangium.
Learn more about the gymnosperm here:
brainly.com/question/4526473?referrer=searchResults
