Bio key concepts

Question 1

cell theory

Answer 1

• All living things are made up of one or more cells and their products
• The cell is the simplest unit that can carry out life processes
• All cells come from other cells, they do not come from non-living matter

Question 2

Organelle

Answer 2

a specialized part of a cell having a specific function

Question 3

Cell cycle

Answer 3

-The Cell Cycle has 2 parts:
1. Interphase:
Cell repairs any damages, re-energizes, grows and prepares for division.
2. Mitosis & Cytokinesis:
Division of the cell into 2 identical “daughter”cells.

Question 4

Interphase

Answer 4

ongest stage of the cell cycle, a cell spends 90% of its time here.
The cell is growing while still performing its usual tasks
First Gap Phase (G1):
Cells grow in size. New proteins and organelles are made.
Synthesis Phase (S):
DNA is replicated (known as chromatin).
Second Gap Phase (G2):
Cells prepare for division.

Question 5

Mitosis - Stage 1 of Cell Division

Answer 5

Process that divides up the contents of the nucleus)
Has 4 phases:
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis (division of the cytoplasm/organelles)
Original cell splits into two daughter cells

Question 6

Chromosomes

Answer 6

Human cells contain 23 pairs of chromosomes.
When a cell divides, each daughter cell gets the same 23 pairs of chromosomes.

Question 7

Prophase

Answer 7

Nuclear membrane breaks down.
DNA condenses to form paired chromosomes (sister chromatids joined together by a centromere).
Centrioles move to each pole.
Nucleolus disappears.

Question 8

Metaphase

Answer 8

Spindle fibers form each pole attach to the centromere of each chromosome.
All chromosomes line up at metaphase plate in the middle of the cell

Question 9

Anaphase

Answer 9

Centromere of each chromosome splits, separating each sister chromatid into “daughter chromosomes”
Spindle fibers shorten, pulling each daughter chromosome to opposite poles of the cell
Cell elongates

Question 10

Telophase

Answer 10

Spindle fibers disappear.
Daughter chromosomes untangle and stretch out becoming chromatin again and are no longer visible
Nuclear membrane reappears around DNA of each new cell

Question 11

Plant Cells

Answer 11

A Cell plate forms in the middle of the cell and splits the cell into two new daughter cells

Question 11

Cell Division Part 2 - Cytokinesis

Answer 11

Final stage of cell division
Cell membrane pinches inwards.
Cytoplasm and all contents are divided into two new daughter cells
Daughter cells return to interphase

Question 12

Animal Cells:

Answer 12

A cell furrow pinches in from middle of the cell creating two new daughter cells

Question 13

Cancer

Answer 13

Genetic mutations can cause cells to mutate and undergo abnormal cell division.
Instead of undergoing apoptosis, these cells divide uncontrollably, spreading cancer and causing different types of cancer.

Question 14

Cellular Differentiation

Answer 14

The process of creating specialized cells
All cells in the body originated from the zygote undergoing mitosis.
As an embryo develops, cells change their shape, contents and function.

Question 15

Stem Cells

Answer 15

Cells that can differentiate into many different cell types.

The daughter cells have the same DNA, but different genes may be turned on or off.

Question 16

Tissue Types

Answer 16

Tissues are a collection of similar cells that perform specific functions.
Animals have 4 types of tissue:
1. Epithelial.
2. Muscular.
3. Connective.
4. Nervous.

Question 17

Epithelial Tissue

Answer 17

Line the internal and external surfaces of the body.
Form a barrier by connecting adjoining cell membranes.

Question 18

Muscular Tissue

Answer 18

Move the body or organ by contracting and relaxing.

Question 19

Connective Tissue

Answer 19

Strengthens, supports and protects other tissues.
Cells are in an extracellular matrix.

Question 20

Nervous Tissue

Answer 20

Made of neurons with long projections that send and receive signals.
Coordinates body actions.

Question 21

organs

Answer 21

heart, liver, alveoli, esophagus, trachea, capillaries, bronchioles, lungs, arteries, and small intestine

Question 22

organ system

Answer 22

digestive - The organ system that takes in food, digests it, and excretes the remaining waste.

Consists of:
1. The Digestive Tract (mouth, esophagus, stomach, small intestine, large intestine, anus)
2. Accessory Organs (liver, gall bladder, pancreas)

respiratory - Is responsible for taking in oxygen and removing carbon dioxide from the body
the lungs, the bronchi , and the trachea (windpipe)
Air comes in through the mouth and/or nose then travels down the pharynx (throat)
the air goes down the trachea and then divides into 2 branches, one for each bronchi.The bronchi lead to the lungs

Circulatory - The circulatory system carries blood and dissolved substances to and from different places in the body.
1. artery - Arteries carry blood away from the heart
2. vein - Veins carry blood towards the heart
3. capillaries - Capillaries link arteries with veins