LEC3

Question 1

A scientist confirms their resource by proving their hypothesis, true or false?

Answer 1

False! No amount of testing can “prove” a hypothesis, we can only confirm it. When we figure out something, we are not sure if we are spot on.

Question 2

How does a hypothesis gains support?

Answer 2

By surviving various tests. This testing falsifies other alternative hypothesis.

Question 3

Experiments must be designed to test control groups and experimental groups, why?

Answer 3

You must have something to compare your experimental design to.

Question 4

Is evolution a hypothesis?

Answer 4

No, because it is a theory.

Question 5

What is the difference between a hypothesis and a theory?

Answer 5

A scientific theory is supported by a large body of evidence. It is much broader than a hypothesis, and generates new hypothesis.

Question 6

When can you call something a theory?

Answer 6

When a hypothesis is always confirm over and over again.

Question 7

Why don’t we call a theory a fact, or a law?

Answer 7

Because in science we know that we have biases. We’re always going to be imperfect humans, in our way of grasping objective reality.

Question 8

Why must you submit your experiment for peer review?

Answer 8

So that experts can point out flaws in the experiment and suggest doing it in another way. If they accept it, it will be publish for others to test out for accuracy.

Question 9

Has the Theory of Evolution been falsified?

Answer 9

No! It has been confirmed and expaneded by many experiments over a hundred years.

Question 10

What is the difference between information revealed by religious leaders, and scientists?

Answer 10

Knowledge gained from science focus on the accuracy of the natural universe. It can be added to, and modified as new information arises. The world is changing fast?

Question 11

Does science disprove religion?

Answer 11

No! There are lots of scientists that have religious faith. Even the pope acknowledged there is no contradiction for religous people to accept that evolution is operating all around and on us.

Question 12

In science you must be vigilant in recognizing your what?

Answer 12

Biases!
・€Always aim for objectivity
・€Always open to new possibilities

Question 13

What is another theory that has been confirmed, expanded and never contradicted?

Answer 13

The Cell Theory! It has been around for over 300 years. It states that cells are the unit that built structures of all living things.

Question 14

What is the best characteristic that best distinguishes living things?

Answer 14

The ability to reproduce.

Question 15

Reproducing start by cell division in a cycle. What is this cycle called, and how does it work?

Answer 15

The Cell Cycle. The cell go through the process of copying it’s genetic materials, and divid into two cells that are identical to the original. It is one of Biology’s major themes.

Question 16

Unicellular(single cell) organisms reproduce by division. What will become of the new cells?

Answer 16

Each new cell will be an individual organism, becoming two identical daughter cell. They can divide almost instantly.

Question 17

Multicellular organisms use cell division for what?

Answer 17

Development, Growth, and Repair. This process is always happening in our body.

Question 18

What can cell division do for multicellular organisms such as plants, by cutting and replanting?

Answer 18

Produce their offsprings.

Question 19

What does cell genetically produces during Cell Division?

Answer 19

Identical daughter cells. Each parent cell duplicates its genetic material before it divides, so each daughter cells has an exact copy of the parent’s DNA.

Question 20

What does the DNA in each cell contains?

Answer 20

The complete genome for an entire organism. This means that each cell has all the information to make an entirely new you.

Question 21

How many base pairs are in one DNA strand that make up a human?

Answer 21

About 6 billion.

Question 22

How many cells make up a human body?

Answer 22

Roughly 200 trillion.

Question 23

What is the total length of a human’s DNA?

Answer 23

About 400 billion kilometers. That’s about 1000 trips to the sun and back.

Question 24

DNA molecules that are packaged into structures are called?

Answer 24

Chromosomes.

Question 25

What are the typical body cells called, that have 2 sets of chromosomes? How many pairs of chromosomes does it have inside humans?

Answer 25

Somatic cells! There are 23 pairs, totaling up to 46 chromosomes. They make up almost the entire human body.

Question 26

What are the sex cells called that has one set of chromosomes? How many chromosomes does it have inside humans?

Answer 26

Gametes! Human gametes have 23 total.

Ex: Sperm and egg.

Question 27

Before cell division, the DNA in each chromosomes uncoils and gets replicated in a cell. What is this process called?

Answer 27

Synthesis!

Question 28

Once the DNA been replicated, what happens to it?

Answer 28

The DNA coils back up into chromosomes, it separate and form two identical daughter cells.

Question 29

Once a DNA/chromosome replicates in a cell, it creates two identical halves called?

Answer 29

Sister chromotids! They are different from chromosomes. They will seperate into two chromosomes, and will be distributed into two daughter cells.

Question 30

What are two major phrases in eukaryotic organisms like humans that the cell cycle has?

Answer 30

1) Interphase - cells spend 90% of their time growing, taking in energy, and replicating their DNA.
2) Cell division: Mitosis - when cells are ready, they divide into two daughter cells. The daughter cells then repeats the cycle.

Question 31

How many times can a cell repeat the cell cycle before they die?

Answer 31

About 50 times.

Question 32

How often does a typical human cell divide?

Answer 32

They might divide once every 24 hours depending on what body parts the cells come from.
Ex: Cells in you skin and blood do it more often.

Question 33

The final end of the division process is called?

Answer 33

Cytokinesis, or cleavage. It forms a furrow in the cell membrane, where it will divide.

Question 34

How can you tell if DNA synthesis has occured in a cell?

Answer 34

When every chromosomes are duplicated and each has two identical sister chromatids.

Question 35

What kind off cells don’t respond normally to the body’s control mechanisms and form tumors, while dividing indefinately to regular cells?

Answer 35

Cancer cells!

Question 36

A common cancer is breast cancer. It start with one cells that divides over and over, forming a tumor that can what?

Answer 36

Metastasize! In other words, export cancer cells to other parts of the body where they may form secondary tumors.

Question 37

What explains how sex cells are produced in the gonalds?

Answer 37

Meiosis!