Biology Notes, Questions, and Study Resources

class 12 NCERT BIHAR BOARD (INDIA)

what is inhibitory gene interaction or dominant supressor gene interaction?

To cause cancer, proto-oncogenes require _____ allele(s) to be mutated and therefore are considered ________. The mutation results in a ___ of function.

While webbed feet were evolving in ancestral ducks, with each generation: a) most ducks had about the same amount of webbing on their feet as their parents b) most ducks had more webbing on their feet than their parents c) most ducks had less webbing on their feet than their parents d) the amount of webbing on duck's feet had no relationship with the amount thier parents had

"Q5.1. Which of the following is FALSE? • If a genetic disease reduces fertility and the allele that causes the disease offers no other advantage, the allele will likely eventually disappear, due to natural selection. Natural selection does not favor individuals who are homozygous for the sickle-cell allele, because these individuals typically die before they are old enough to reproduce. Individuals who are heterozygous HbA/HbS are protected from malaria, and this is why sickle-cell disease persists in wetter, mosquito-prone regions in Africa. In regions where malaria does not occur, individuals who are heterozygous HbA/HbS have a fitness advantage over those who are homozygous for the normal hemoglobin allele (HbA)."

"Multiple choice question. Which of the following best describes alleles? Alleles allow DNA to be wrapped and organized into chromosomes. Alleles are the basic unit of inheritance for cells. Alleles are variations of genes and include examples such as eye color, height, and ability to digest lactose. Alleles are specific locations on genes that code for proteins and other protein products. "

What are the four main steps of cellular respiration?

What are 10 biotic factors of the desert? Cacti Desert shrubs Lizards Snakes Desert tortoises Coyotes Desert foxes Insects (e.g., beetles, ants) Birds (e.g., hawks, owls) Scorpions