Answer:
Evolution is driven by rare mutations that occur in the DNA of organisms. These mutations could be lethal, neutral and some advantageous. The lethal mutations cannot exist in a population because the offspring is unable to survive to term in pregnancy or dies just after birth. The neutral are ones that do not considerably affect the organisms – though they could result in a disadvantage. The beneficial ones are the one that is kept in the population by natural selection because they confer an advantage e.g in the fight for resources or escaping predation and etcetera. Therefore, it's like a game of chances by nature. Paleontologists discover many species of organisms some of which are imperfect because nature produced them but they died off because their mutations gave them a disadvantage against better-adapted individuals.
The <em>Tiktaalik</em> fish from 375 million years ago became extinct because it did not well-developed eardrum for detecting vibrations in water which is significant in survival.
Dinosaurs during development of feathers had many imperfect species before the right wings for flight were conjured up by nature. An imperfect species is the <u><em>Tianyulong confucius</em></u> had stiff feathers that lacked vanes hence were not ideal for flight
Answer:
The question is incomplete, it lacks the main questions, those questions are:
a. What is the genotype for black chickens?
b. What is the genotype for white chickens?
c. What is the genotype for erminette chickens?
Explanation:
This question involves a gene coding for feather colour in some birds, in which the black allele (B) and white allele (W) is involved. According to the question, the gene coding for feather colour exhibits co-dominance i.e. both the black (B) and white (W) allele are expressed in a heterozygous state (BW) to form an erminette phenotype.
Hence, if the neither alleles is dominant or recessive over the other. The black phenotype will only be expressed when the genotype is BB.
The white phenotype will only be expressed when the genotype is WW
The combination of both alleles which results in the simultaneous expression of both in the erminette phenotype, will be BW genotype.
The axe is an example of a simple machine, as it is a type of wedge<span>, or dual inclined plane. </span>
Answer;
The amnion
Explanation;
-The amnion is a tough, thin membrane that surrounds a developing fetus in mammals, reptiles, and birds. It is the first of the three cavities (amnion, chorion and yolk sac) in the embryo and is formed on 8 dpc.
-In the human body, the amnion is the first of three cavities, including the chorion and yolk sac, that work together to keep the developing fetus nourished and protected.
-The amnion provides a protective environment in which the fetus' temperature is regulated and protects the fetus from friction caused by the mother's movements.
