HW #26 - AP Biology Period 4 #22 Liem Nguyen 1/4/10...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
AP Biology Period – 4 #22 Liem Nguyen 1/4/10 Homework #26 ( 090213 ): Chapter 26 (due Friday 090213 ) Total points: 40 for Attempt on all questions Concept Map: 10 Points The Tree of Life: An Introduction to Biological Diversity Objectives The Origin of Life 1. Describe the four stages of the hypothesis for the origin of life on Earth by chemical evolution. abiotic synthesis joining of monomers protobionts self-replicating Life on Earth is hypothesized to have emerged through four steps, the first of which being abiotic synthesis of small organic molecules. These molecules join together to form polymers, which package themselves into protobionts, and finally, the origin of self-replicating molecules that eventually made inheritance possible. 2. Describe the contributions that A. I. Oparin, J.B.S. Haldane, and Stanley Miller made toward developing a model for the abiotic synthesis of organic molecules. Describe the conditions and locations where most of these chemical reactions probably occurred on Earth. reducing environment lightning and UV radiation lab experiment nitrogen/carbon dioxide volcanoes and deep-sea vents Oparin and Haldane thought that Earth’s atmosphere was a reducing environment, or constantly adding electrons. The energy could have come from lightning and intense UV radiation. They thought that organic molecules came from oceans. Miller and Urey, created a lab experiment, mimicking conditions of Earth’s beginnings, which produced organic compounds. They discovered that early atmosphere was made up mostly of nitrogen and carbon dioxide, and that the first organic compounds originated from volcanoes and deep-sea vents. 3. Describe the evidence that suggests that RNA was the first genetic material. Explain the significance of the discovery of ribozymes. Thomas Cech (Colorado) Sidney Altman (Yale) central role
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
ribozymes catalytic functions replication It was discovered by Thomas Cech and Sidney Altman that not only does RNA play a central role in protein synthesis, but it also carries out a number of enzyme-like functions. The enzyme-like RNA was called ribozymes. Ribozymes were capable of replicating RNA. 4. Describe how natural selection may have worked in an early RNA world. RNA molecules assume different shapes best-suited sequence of RNA molecules descendants are closely related RNA molecules are capable of forming a variety of specific three-dimensional shapes. Those molecules whose sequence are best suited to the surrounding solution and have the greatest autocataytic activity will replicate most often. The descendants will be a closely related family, due to copying errors, leading to more diversity.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/06/2011 for the course AP BIO 101 taught by Professor Chan during the Fall '05 term at JFK.

Page1 / 6

HW #26 - AP Biology Period 4 #22 Liem Nguyen 1/4/10...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online