CH: 1 Introduction to botany Flashcards
Chapter 1
The word botany means?
Plants
List some of the ways plants are important:
Food, fiber for clothes, wood, shelter, fuel, drugs for medicine, and the oxygen we breathe.
Stromatolite fossils are 3.5 billion years old. What type of evidence of life do these rocks contain?
These rocks contain several kinds of microorganisms that resemble bacteria.
What has been discovered on Mars?
It was discovered that water flowed across the planet.
List the 4 characteristics of life:
the ability to grow, reproduce, pass their characteristics to subsequent generations, respond to stimules.
Which evolved first, heterotrophic or autotrophic, life forms?
Heterotrophic
What is the geological evidence of autotrophic activity at 3.4 billion years ago?
Evidence of photosynthetic organisms was found in rocks.
From 3.4 to 2.2 billion years ago organisms with photosynthesis released oxygen, but the world’s atmosphere remained anaerobic. Why?
The oxygen released into the ocean and lakes reacted with dissolved iron and precipitated as iron oxides, It took a billion years to oxidize all the minerals, and decsuse of this no oxygen was in the atmosphere.
Why did landforms only appear after 450 million years ago?
Some oxygen molecules in the outer layer of the atmosphere were converted into ozone. Ozone absorbs ultraviolet rays, 450 million years ago it protected organisms sufficiently so they could survive in the surface layers.
Eukaryotic cells appear about 2.1 billion years ago. What factor, or process, was related to their evolution?
The increase of abundant free oxygen made eukaryotic cells appear since the Krebs cycle was being done.
Multicellular life, 650 million years ago, had an advantage over unicellular life forms. What environmental factor was limiting?
Life began to develop at shore and it was more difficult than at open sea. Organisms evolved in which many cells were linked together to form a multicellular body.
Why were cell walls formed by plants moving into freshwater?
Cell walls enabled them to survive and thrive in less stable and more challenging freshwater environments.
Conducting cells in algae were needed for parts growing in low light. why?
Parts of the organisms were not photosynthesizing, this tissue extended their length and connected the parts that photosynthesize to ones that couldn’t.
If an epidermal cuticle prevents desiccation, what structures evolved to allow gas exchange?
The stomata open and close in response to environmental and physiological signals, this helps the plant maintain a balance in water and lose oxygen and carbon dioxide.
Compare annual and perennial
Annual- Short life span
Perennial- More life span
