Cell Unit Test Flashcards Practice

Where did earth start

Earth likely started under water near white smokers, or hydrothermal vents because these were not too hot and had the necessary compounds and molecules for life to begin. They also had a chemical gradient as a stable energy source, and the harmful UV radiation, meteors/asteroids, and volcanic eruptions resulted in a hostile environment for life to begin.

Describe the levels of life.

cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere.

What is science

the systematic study of the structure and behavior of the physical natural world through observation, experimentation, and the testing of theories.

What are the 7 characteristics of life?

responding to stimuli, growing and developing, reproducing, using energy, being made of cells, having homeostasis, and containing genetic material.

Why is it difficult to define life?

Origins of life were gradual, there is no exact line of characteristics, life can be either more chemically or physically based, and living-things are mad of non-living things which confuses.

What are the differences between prokaryotic and Eukaryotic cells?

Prokaryotic cells lack nucleus and other membrane bound organelles, they came first about 3.7 bya, they are bacteria and archaea, they are unicellular, and microscopic. On the contrary, eukaryotic cells have nucleus and other membrane bound organelles, they’re more complex, they came later about 2.7bya, they can multi or unicellular, and have a huge variation is size.

Define the nucleus

The nucleus is membrane bound, where DNA is stored and replicated, and DNA is converted to RNA for transcription as it cannot fit through pores. It is the control center of the cell.

Nucleolus

The densely packed part of the nucleus which creates parts for ribosomes

Ribosomes

The protein complex, it translate RNA into proteins for the cell that can be exported to other parts of the organism to work.

1. List 3 differences between prokaryotic and eukaryotic cells

1. Prokaryotic cells lack the nucleus and other membrane-bound organelles unlike eukaryotic cells.

2. Prokaryotic cells came before eukaryotic cells, they’re older.

3. Prokaryotic cells are unicellular but eukaryotic cells can be single or multicellular.

what does being membrane bound mean

To be membrane bound means to be surrounded by the cell membrane, or having a layer of lipids enclosing the organelle.

What organelle is responsible for creating proteins?

Ribosomes are responsible for creating proteins for the cell.

1. How are proteins used in the body (in other words, what do proteins do?)?

Proteins repair your tissues and help metabolic processes take place for bodily functions.  *Forms Channels going through membranes, pumps to get things In and out.

1. What is the function of the nucleus, mitochondria, endoplasmic reticulum (ER), and plasma/cell membrane?

Nucleus: The nucleus is the control center of the cell which contains most genetic material Mitochondria: Mitochondria is the powerhouse of the cell, and packs energy from food (glucose) into ATP molecules. Larger cells needing more work have more mitochondria ER: Smooth ER makes lipids in the cells and helps detoxify harmful substances whereas the rough ER has ribosomes and helps protein synthesis occur. ER helps transport proteins out too, and protein is created.  Plasma/cell membrane: It separates the rest of the environment from the inside of the cells, it is made of 2 layers of lipids. Holds the contents of the cell, allows homeostasis.

1. What are 3 differences between plant and animal cells?

Animal cells do not have chloroplasts whereas plant cells do. Animal cells have many small vacuoles whereas the plant cell has one, big vacuole. Plant cells have cell walls whereas animal cells don’t.

Why was “young earth” too harsh for life to begin? What conditions were needed to kick-start life?`

Earth was initially way too hot and did not have enough oxygen for life to begin.  The UV rays were too harsh and all in all, the atmosphere wasn’t ok. A stable environment with oxygen was necessary for life. There was way too much volcanic activity and hostile conditions. Asteroids and meteors would always be hitting earth. Earth needed the right types of molecules such as oxygen, carbon, hydrogen, etc. and needed a stable energy source to lead to life. Smokers provided all of this such as water, and they hit the mantle to take out all of these molecules.    

What is a virus?

A virus is something that infects and  has genetic material like DNA or RNA surrounded in a coat of protein, and is defined by the scientific community. A virus uses hosts for energy and reproduction. It has a genome and is quite close to living thing.

cells

protein based robots too small to feel/experience anything, ha properties we assign to life, wall seperating it from surroundings creating order, regulates itself and maintains constant state, eats to stay alive, grows and develops, eveolves, reacts to environment, multiplies NONE OF THIS IS ALIVE

viruses are

strings of rna or dna in a small hull needing cells to function

what did scientists find out about luca

luca lived in an oxygen free hot place, which was probably in white smokers hydrothermal vents cuz it wasnt as hot as black smokers which were too hto but had the necessary chemicals for life but the mid atlantic ridge or lost city was prob where white smokers with adjacent black smokers were helpful for cradle of life luca