Answer:
'Cross experiments done by Morgan, illustrating the X-inheritance link of a mutation Thomas Hunt Morgan moved intensely in a program of breeding and crossing miles of fruit flies at New York University in a room that was renamed the Fourth of the Flies. He tried to mutate the flies with various means (X-rays, centrifuges, etc.) .The fruit fly which has 4 pairs of chromosomes. One of those pairs was identified as containing X and Y sex chromosomes. He applied Mendelian principles in flies. Morgan's inheritance study demonstrated inheritance linked to sex, and is one of the first evidences that confirm the chromosomal theory of cross-based inheritance. In 1909, Morgan detected a fruit fly (Drosophila melanogaster) with a strange mutation which he called "white eyes", due to the coloration of his eyes (contrary to normal, which is red). Analyzing this fly under the microscope Morgan discovered that it was a male, and could use it as a stallion so that he could observe how the new characteristic of white eyes would pass from generation to generation.All the offspring of this cross will have red eyes, which He made Morgan suspect that something strange had happened, since the color of the father's eyes could not have disappeared. He decided to take a couple of "daughters flies" and cross them together, just to see what happened. Morgan's surprise was very great, observing that among the "granddaughters" flies only males had white eyes. The problem then was to explain what had happened during the hereditary transmission for the color of the white eyes only the males possessed. .
Answer:
Normal daughters and Hemophiliac son
Explanation:
Females exhibit hemophilia and colorblindness in homozygous genotype only.
The genotype of hemophiliac woman= X^hX^h
The genotype of colorblind man= X^cY
A cross between X^hX^h and X^cY would produce progeny in the following phenotype ratio= 1 Normal but carrier daughters:1 Hemophiliac son
biotic- living things
abiotic- non living things
The energy from sunlight comes in the form of photons, and this energy is used in the light dependent reactions of photosynthesis. The first function carried out by the photons in energizing electrons in the chlorophyll. The energized electron travels through the electron transport chain and subsequent steps are carried out to utilize this energy to form ATP.
Answer: The study, by Dr. Tim Brodribb and Dr. Taylor Field of the University of Tasmania and University of Tennessee, used plant physiology to reveal how flowering plants, including crops, were able to dominate land by evolving more efficient hydraulics, or 'leaf plumbing', to increase rates of photosynthesis.
Explanation: The reason for the success of this evolutionary step is that under relatively low atmospheric C02 conditions, like those existing at present, water transport efficiency and photosynthetic performance are tightly linked. Therefore adaptations that increase water transport will enhance maximum photosynthesis, exerting substantial evolutionary leverage over competing species.
The evolution of dense leaf venation in flowering plants, around 140-100 million years ago, was an event with profound significance for the continued evolution of flowering plants. This step provided a 'cretaceous productivity stimulus package' which reverberated across the biosphere and led to these plants playing the fundamental role in the biological and atmospheric functions of the earth.
