I think the correct answer would be the last option. Monozygotic twins are identical, while dizygotic twins are fraternal. Identical twins involves developing from one zygote where it splits, forming two embryos so that the twins would have more or less the same characteristics. This type of twins can share the same amniotic sac depending on the time the fertilized egg is divided. On the other hand, fraternal twins developed from two eggs wherein they are being fertilized by two different sperm cells resulting to twins which has different characteristics. For this type, the two fertilized eggs would develop separate amniotic sacs.
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.
<span>A pedal steel guitar uses foot pedals and knee levers. It </span>allows the player to change pitches with his feet and knees (apex). <span>A pedal (or foot pedal) is something you can use if you want to alter the sound coming from your guitar or add various sound effects.</span>