English class VI
Critical Thinking Worksheet
1. Read the following passage and answer the
questions at the end.
And yet it is one of the simplest ideas that anyone ever
had. Here I want to persuade you how evolution
explains the beginning of life on earth. Darwin
uncovered the theory of evolution and the method of
natural selection. The idea of evolution is probably one
of the most important ideas that anyone has ever had.
Today, thanks to Darwin, we know why life is the way
it is. We can predict how life will be in the future. We
can even postulate about the life on other planets.
Q 1. Give the central Idea of the passage.(word limit
from 30 to 40 words)
2. Read the paragraph and answer the question
that follows:
Sedimentary rocks are formed by the process of
sedimentation. Layer after layer of minerals is
deposited over a great span of time, resulting in the
formation of a sedimentary rock. As a result, each layer
is different if the conditions under which its deposits
were different. Thus we can say that a sedimentary
rock is a sort of museum, holding the records of all the
time over which it was formed, which by all means can
be as long as a billion years.
Q1. Explain the meaning of the passage in your
own words.(word limit from 30 to 40words)
Answers
Answer:
Ans- Q1 Introduction of evolution-
Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species, and share a common ancestor.
The mechanism that Darwin proposed for evolution is natural selection. Because resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations.
Natural selection causes populations to become adapted, or increasingly well-suited, to their environments over time. Natural selection depends on the environment and requires existing heritable variation in a group.
The basic idea of biological evolution is that populations and species of organisms change over time. Today, when we think of evolution, we are likely to link this idea with one specific person: the British naturalist Charles Darwin.
In the 1850s, Darwin wrote an influential and controversial book called On the Origin of Species. In it, he proposed that species evolve (or, as he put it, undergo "descent with modification"), and that all living things can trace their descent to a common ancestor.
Ans- Q2 Formation of sedimentary rock- Sedimentary rock, rock formed at or near Earth’s surface by the accumulation and lithification of sediment (detrital rock) or by the precipitation from solution at normal surface temperatures (chemical rock). Sedimentary rocks are the most common rocks exposed on Earth’s surface but are only a minor constituent of the entire crust, which is dominated by igneous and metamorphic rocks.
Sedimentary rocks are produced by the weathering of preexisting rocks and the subsequent transportation and deposition of the weathering products. Weathering refers to the various processes of physical disintegration and chemical decomposition that occur when rocks at Earth’s surface are exposed to the atmosphere (mainly in the form of rainfall) and the hydrosphere. These processes produce soil, unconsolidated rock detritus, and components dissolved in groundwater and runoff. Erosion is the process by which weathering products are transported away from the weathering site, either as solid material or as dissolved components, eventually to be deposited as sediment. Any unconsolidated deposit of solid weathered material constitutes sediment. It can form as the result of deposition of grains from moving bodies of water or wind, from the melting of glacial ice, and from the downslope slumping (sliding) of rock and soil masses in response to gravity, as well as by precipitation of the dissolved products of weathering under the conditions of low temperature and pressure that prevail at or near the surface of Earth.
The three major categories of sedimentary rocks are recognized: (1) terrigenous clastic sedimentary rocks, (2) carbonates (limestone and dolomite), and (3) noncarbonate chemical sedimentary rocks.