Unit 2 concept 1-3 notes

Question 1

Unicellular:

Answer 1

Made of a single cell

Question 2

Multicellular:

Answer 2

Consisting of many cells

Question 3

Organelle:

Answer 3

specialized structure that performs important cellular functions within a eukaryotic cell

Question 4

List the 3 principles of cell theory:

Answer 4

1. All living things are made of cells
2. Cells are the basic unit of life
3. All cells come from other cells

Question 5

Create a Venn diagram comparing prokaryotic and eukaryotic cells.

Answer 5

Prokaryotic: Has cell wall, no nucleus
Eukaryotic: Has nuclues, has membrane beyond organelles
Both: Cytoplasm, Ribosomes.

Question 6

List the structures that distinguish plant cells from animal cells

Answer 6

The structures that only plant cells have and not animal cells have are that plant cells have chloroplasts, cell walls, and central vacuoles.

Question 7

Describe the function of the following organelles: cell (plasma) membrane, cytoskeleton, cytoplasm, nucleus, nucleolus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuole, centrioles (centrosome), cilia, flagella, mitochondria, chloroplast, and cell wall.

Answer 7

Cell membrane: The cell membrane’s job is to control what goes in and out of the cell.

Cytoskeleton: The cytoskeleton gives the cell its shape.

Cytoplasm: The cytoplasm holds everything in place

Nucleus: The nucleus protects the DNA that controls the activities of the cell.

Nucleolus: The nucleolus makes the rRNA which makes up ribosomes.

Rough Endoplasmic Reticulum: The rough endoplasmic reticulum or rough ER makes proteins, packages them for secretion and sends them in the vesicles to the Golgi.

Smooth Endoplasmic Reticulum: The smooth endoplasmic reticulum or smooth ER makes lipids and stores Ca+2.

Golgi Apparatus: The Golgi apparatus gets the vesicles of protein from the ER and transports them around the cell.

Lysosomes: Lysosomes break down dead stuff and can be programmed to self-destruct.

Vacuoles: Vacuoles hold storage like water, nutrients, waste, etc.

Centrioles (Centrosome): Appear during cell division and help cells divide by pulling chromosomes apart.

Cilia an

Question 8

Defend the claim that ribosomes are the most essential organelle in the cell. In your reasoning include evidence of at least 3 organelles that support the ribosome in accomplishing its function for the cell.

Answer 8

Ribosomes are the most essential organelle in the cell because they are intertwined with 3 other organelles. The smooth and rough ER as well as the cytoplasm. Ribosomes are in the rough ER and they help make proteins. The smooth ER is attached to the rough ER and shares lipids with the rough ER and the ribosomes. Ribosomes are also in the cytoplasm and help it make proteins to use in the cell.

Question 9

Homeostasis

Answer 9

The need of an organism to stay stable by regulating internal conditions

Question 10

Solute

Answer 10

What gets dissolved

Question 11

Solvent

Answer 11

Does the dissolving

Question 12

Solution

Answer 12

Uniform mixture of two or more substances

Question 13

Concentration

Answer 13

Amount of solute dissolved in a solvent

Question 14

Concentration gradient

Answer 14

Difference in concentration of a substance from one location to another

Question 15

Phagocytosis

Answer 15

cell eating

Question 16

Pinocytosis

Answer 16

cell drinking

Question 17

Differentiate between dynamic and state equilibrium with regard to homeostasis.

Answer 17

Dynamic equilibrium is maintained though it doesn’t stay the same it’s within the range while homeostasis stays stable the entire time.

Question 18

Describe the relationship between a response to stimuli and homeostasis.

Answer 18

A response to stimuli compared to homeostasis is that a stimulus is a change in environment so it has to react to stay in homeostasis but homeostasis is something that stays the same no matter what.

Question 19

Differentiate between positive and negative feedback loops. Include two examples of each.

Answer 19

In a positive feedback loop the output of the system intensifies the response like childbirth or fruit ripening.

In a negative feedback loop the output of the response causes the system to counter response to return to the set point like the human body temperature or blood sugar regulation.

Question 20

Explain the role of the cell membrane in maintaining homeostasis on a cellular level. Include which substances can and cannot pass through easily.

Answer 20

The role of the cell membrane in maintaining homeostasis is by controlling what goes in or out of the cell. The substances that can go through the cell are small, nonpolar, hydrophobic, neutral molecules as well as water. What can’t go through the cell are polar and large molecules.

Question 21

Differentiate between passive and active transport.

Answer 21

Passive transport requires no extra energy because it moves from high concentration to low concentration. Active transport requires extra energy because it moves from low concentration to high concentration.

Question 22

Describe (either with words or drawings) the six types of transport. List examples of substances transported via each method.

Answer 22

The 6 types of transportation are simple diffusion, facilitated diffusion, osmosis, molecular pumps, exocytosis, and endocytosis.

Simple diffusion: carries O2 and CO2 and small nonpolar molecules

Facilitated diffusion: Carries large molecules like glucose and polar molecule like calcium

Osmosis: Carries water

Molecular pumps: Carries potassium, chlorine, and sodium.

Exocytosis: When nerve cells secrete neurotransmitters to send signals throughout the body.

Endocytosis: When white blood cells engulf bacteria in order to fight infections.

Question 23

Explain the difference between hypotonic, isotonic, and hypertonic solutions. You may use a picture to help you describe it.

Answer 23

The difference between hypotonic, isotonic, and hypertonic is that hypotonic water is lower the cells cytoplasm while hypertonic water is higher than the cells cytoplasm. Isotonic means its equal inside and outside.

Question 24

Differentiation

Answer 24

A process that creates special structures and functions

Question 25

Stem cells

Answer 25

Stem cells: Undifferentiated cells that become differentiated into one or more types of specialized cells

Question 26

Gastrula

Answer 26

Embryo with 3 differentiated germ layers

Question 27

Organogenesis

Answer 27

The process of body organ and organ system formation that follows gastrulation.

Question 28

Cell cycle

Answer 28

A repeated pattern of growth, DNA duplication and cell division that occurs in eukaryotic cells.

Question 29

Chromosome

Answer 29

One long continuous thread of DNA that consists of thousands of genes and regulatory information.

Question 30

Gene

Answer 30

A section of DNA that contains the instructions for making a protein.

Question 31

Sister chromatids

Answer 31

Two identical chromatids.

Question 32

Centromere

Answer 32

Region of the condensed chromosomes that looks pinched.

Question 33

Telomere

Answer 33

Ends of the DNA molecule.

Question 34

Cancer

Answer 34

Uncontrolled cell division.

Question 35

Metastasize

Answer 35

Spreading of disease from one organ to others.

Question 36

Carcinogens

Answer 36

Cancer causing agents; chemicals that cause cancer by mutating DNA.

Question 37

Summarize the order of events from egg and sperm to embryo.

Answer 37

The sperm enters the egg and fertilizes it.

Question 38

Explain the difference between specialized cells and stem cells.

Answer 38

Specialized cells come in different types like tissues, organs, and organ systems while stem cells can transform into any of them.

Question 39

List the levels of organization from cell to organism that result from differentiation.

Answer 39

Cell, Tissue, Organ, Organ system, and Organism.

Question 40

List the two main purposes for cell division.

Answer 40

The two main purposes for cell division are growth and repair.

Question 41

Sketch and label a homologous chromosome pair before and after S phase. Include a brief description of the importance of S phase.

Answer 41

Because of S phase, at the end of interphase the cells has 2 full set of chromosomes.

Question 42

Describe all the phases of the cell cycle, including the phases in interphase and mitosis, in order.

Answer 42

The phases of the cell cycle start with the interphase phases.

G1 or gap 1 phase: the cells grow and make proteins.

Synthesis phase: DNA replication occurs by doubling the number of chromosomes.

Gap 2 phase: More cell growth and protein synthesis.

Mitosis: Division of the cell cycle.

Prophase: Chromosomes are condensed and are visible as sister chromatids.

Metaphase: Spindle fibers connect to the centromere of each sister chromatid.

Anaphase: sister chromatids separate pulling away from each other and becoming individual chromosomes.

Telophase: Chromosomes decondense and start to look like chromatin again.

Cytokinesis: Division of cytoplasm into 2 individual cells.

Question 43

Differentiate between cytokinesis in plants and animal cells.

Answer 43

Cytokinesis in plants forms midway between divided nuclei and gradually develops into a membrane. Cytokinesis in animal cells forms cleavage furrow that pinches the cell into 2 equal parts.

Question 44

Summarize how cells know when they need to divide. Include examples of the difference between internal and external regulation.

Answer 44

Cells know when they need to divide because each cell divides at a different time based on its needs. If they are in the internal lining of intestines its every 5 days but if it’s like of liver cells its every year. The difference between internal and external regulation is that during internal regulation it sends out signals from inside their nucleus like DNA inside a cell but external regulation sends signals out from outside of the cell like hormones or nutrients.

Question 45

Explain the key roles of checkpoints and apoptosis in the regulation of the cell cycle.

Answer 45

The key role of checkpoints and apoptosis in the regulation of the cell cycle is that the checkpoints are the critical points where stop and go signal regulate. What the apoptosis does is that it has a programmed cell death and it produces self- destructive enzymes.

Question 46

Define tumors and differentiate between the two types.

Answer 46

Tumors are clumps of cells that divide uncontrollably. The difference between the two types which are benign and malignant is that benign tumors are clustered and can be harmless and easily removed unlike malignant tumors where they break away and move to other parts of the body making it dangerous and harder to remove.

Question 47

List several potential causes of cancer.

Answer 47

Some potential causes of cancer are biological factors like your age, skin type and inherited genetic mutations. Your life style like your diet, physical activity, exposure to uv radiation. Viruses and other infections like HPV. Another possible cause is exposure to carcinogens like cancer causing agents, chemicals that cause cancer by mutating your DNA like tobacco smoke, asbestos and many more.