Question

directed reading b
section: eras of the geologic time scale
circle the letter of the best answer for each question.

1. what are the four eras pass in geologic history?

a. precambrian, paleozoic, mesozoic, and cenozoic
b. precambrian, paleozoic, mesozoic, and mammals
c. paleozoic, mesozoic, cenozoic, and modern
d. paleozoic, mesozoic, mammals, and modern
precambrian time

1. what first appeared on earth during precambrian time?

a.
b.
c.
d. bacteria
how did life begin?

1. what do scientists think the earliest living things grew near?

a. oxygen
b. rocks
c. volcanic chimneys
d. photosynthesis

1. how many cells did the first living things, prokaryotes, have?

a. many
b. one
c. thousands
d. hundreds

directed reading b continued
photosynthesis and oxygen
read each description. then draw a line from the dot next to each
description to the matching word.

1. i drop things into the mud

a. photosynthesis
b. ozone
c. cyanobacteria
d. oxygen

1. i turn sun, water, and carbon dioxide into food from sunlight
2. i screen out some of the sun’s harmful rays

multicellular organisms
circle the letter of the best answer for each question.

1. after prokaryotes first formed, what kind of living things appeared?

a. bacteria, less complex
b. archaea, more complex
c. eukaryotes, more complex
d. virus

1. what key advantage do eukaryotes have over prokaryotes?

a. organelles made of new cell
b. organelles
c. eukaryotes made of new cell
d. nucleus
the paleozoic era

1. which geologic era came after the precambrian era?

a. mesozoic
b. paleozoic
c. modern
d. primary

Explanation:

Since the problem is about the geologic time scale and related topics like the origin of life and early organisms, the relevant subfield under Natural Science is Geology (which can be considered under the "Geography" or "Others" subfield as per the given list, but more accurately, it's a part of Earth Science which is related to Natural Science). Let's solve one of the questions, say question 3: "What do scientists think the earliest living things grew near?"

Step1: Recall knowledge about early life

Scientists believe that the earliest living things (like prokaryotes) grew near deep - sea hydrothermal vents or areas with chemical energy sources, often associated with volcanic activity or areas rich in simple chemicals. Among the options (though the options are a bit unclear from the image, but from typical questions on this topic), the answer is related to simple chemicals or areas with chemical energy. If the options are like a. oxygen, b. rocks, c. simple chemicals, d. photosynthesis, then the correct answer is c. simple chemicals.

Step2: Eliminate other options

• Option a: Oxygen was not abundant in the early Earth's atmosphere, so early life couldn't grow near oxygen - rich areas.
• Option b: Rocks don't provide the necessary energy or building blocks for early life in the way simple chemicals do.
• Option d: Photosynthesis came later with the evolution of more complex organisms (like cyanobacteria), so early life didn't grow near photosynthesis - related areas.

Step1: Recall prokaryote structure

Prokaryotes are unicellular organisms, meaning they have only one cell.

Step2: Confirm with knowledge

The first living things were prokaryotes, and they are single - celled. So if the options are a. many, b. one, c. hundreds, d. thousands, the correct option is b.

Answer:

c. simple chemicals (assuming the options are as inferred)

For another question, say question 4: "How many cells did the first living things, prokaryotes, have?"