Chapter 9

Questions :

What are Mendel's four hypothesis ?

There are alternative versions of genes that account for variations in inherited chracters.

For each character, an organism inherits two alleles, one from each parent.

If the two alleles of an inherited pair differ, then one determines the organism's appearance and is called the dominant allele,the other has no noticeable effect and is called and is called the recessive allele.

A sperm or egg carries only one allele for each inherited character because allele pairs separate from each other during the production of

gametes.

How technology helps find the chromosomal disorders ?

Due to new technologies we are to get tested for chromosomal disorders. For examples fetal testing, during which the doctor is able to detect harmful genetic conditions of the child, such as Down syndrome etc.... This testing is very helpful because our recessive alleles don't show themselves until we passed them on then they might have chance to affect the genes which could cause some harmful effects.

What is the difference between phenotype and genotype ?

Phenotype is genetic composition that is expre

ssed by organisms. This could be eye color, shape of nose, skin color etc.. On the other hand genotype is the genetic information that is inside the DNA. These are the traits that we're not able to see but we can pass them on and they could show in the next generation.

Diagram :

This diagram shows Punnett square. This square helps to discover the genetic combination if you have two heterozygous plants reproduce.

5facts:

Sex-linked disorders affect mostly males.

One single gene is capable of affecting many phenotype characters.

Environment we are living in may affect many characters.

We have two types of disorders recessive cause by the recessive gene and dominant disorders cause by the dominant gene.

Punnett square shows the possible gene combination based on the Mendel's hypothesizes

Key terms :

Alleles - alternative versions of a gene

Homozygous organism - organism that has two identical alleles

Heterozygous organism - organism that has two different alleles

Phenotype - organism's physical traits

Genotype - organism's genetic traits

Character - heritable feature

Trait - variant for a character

Hybrids - offsprings of two different varieties

Complete dominance - the dominant allele had the same phenotypic effect whether present in one or two copies

Incomplete dominance - some character's phenotype falls between two parental varieties

Video :

Punnett square

Summarize :

Chapter 9 gives a lecture about genetic informations and how are genes inherited. It describes Mendel's hypothesis and Punnett square which shows us the probability of inherited factors.

Chapter 8

Questions:

What are the phases of mitosis ?

First is interphase which lasts the longest time (about 90% of cell's life cycle) during this phase cell performs normal actions. Also this p

hase is divided into 3 sub-phases G1, S (division of DNA), G2. After interphase prophase follows. During prophase cell looses the nucleus and chromosomes become visible. Then there's prometaphase during this phase spindle is created. At metaphase chromosomes align on the metaphase plate. Then during anaphase the chromosomes separate and move toward the pole's of the cell. Telophase is finishing up the division and cytokinesis divides cytoplasm.

What is the difference between cytokinesis and mitosis ?

Cytokinesis represents the process of cytoplasmic division. Also during cytokinesis the cell finally separates into two daughter cells. On the other hand mitosis represents only the division of nucleus and chromosomes.

What is the difference between the products of Mitosis and Meiosis ?

The main difference between the products of Meiosis and Mitosis is that Meiosis produces cells with haploid number of chromosomes (23 for humans); Meiosis leads into creation of four daughter cells not two and these four cells are sex cells (sperm and egg).

Diagram:

This diagram shows Mitosis. The process and sub phases of Mitosis are described in Question 1.

5facts :

Mitosis is cell division.

Due to cross overs during Meiosis the daughter cells have different genetic variation than parent cells.

Meiosis produces four haploid cells and mitosis produces two diploid cells.

Karyotype is display of magnified images that helps the doctor diagnose any chromosomal diseases.

Down's syndrome is one of the most common chromosome number abnormality.

Key terms :

Karyotype - display of magnified images of an individual's chromosomes

Genetic recombination - the production of gene combinations different from those carried by the original chromosomes

Diploid cells - cells with two homologous sets of chromosomes

Haploid cells - cells with a single chromosome set

Fertilization - process when egg and sperm fuse together

Zygote - the resulting fertilized egg

Sex chromosomes - X and Y chromosomes

Autosomes - 22 pairs of chromosomes (sex chromosomes are not included)

Somatic cell - typical cell in human body

Tumor - an abnormally growing mass of body cells

Video :

Mitosis

Summarize : Chapter 8 was presenting Mitosis and Meiosis. The process of cell reproduction and also the abnormalities that can arise from mistakes during the cell division.

Chapter 7

Questions:

Why is photosynthesis so important ?

Photosynthesis creates oxygen out of CO2. That is very important especially for living organisms that need oxygen to be able to breathe.

What does photosynthesis use to make energy ?

At first the plant absorbs light and uses H2O to produce O2. During this time photosynthesis also creates NADPH and ATP so the plant can use it in second process to create sugar out of CO2

What happens during Calvin cycle ?

Calvin cycle occurs in the stroma of the chloroplast. It is a serie of r

eactions that assembles sugar molecules using CO2 and the energy containing products of the light reactions. this stage is named after Melvin Calvin. During this stage happens the most important process the change from inorganic material into organic material.

Diagram :

This diagram shows overall process of photosynthesis. It also shows the flow of ATP and NADPH between the Photosystem I and II and Calvin cycle , which is very important for the phases of photosynthesis.

5facts:

Light reactions include the steps that convert light energy into chemical energy.

Chlorophyll a is light-absorbing pigment in the chloroplast. Chlorophyll plays main role during photosynthesis.

Plants produces O2 as a secondary product of photosynthesis.

Some plants such as C4 and CAM plants are able to save water better than C3 plants, because they first fixate CO2 into a four-carbon compound not three-carbon compound (Calvin cycle).

Photosynthesis can be divided into 2 phases. 1 is when the plant needs light and the 2 is when plant can sustain the process of photosynthesis without light.

Key terms :

Mesophyll - green tissue in the interior of the leaf

Thylakoids - interconnected membranous sacs

Stroma - thick fluid filling up chloroplast

Chlorophyll - light-absorbing pigment

Photoautotrophs - organisms that are able to produce organic molecules from inorganic molecule using the energy of light

Photon - fixed quantity of light energy

Wavelength - distance between the crests of two adjacent waves

Photosystem - consists of a number of light-harvesting complexes

C3 plants - called because the first organic compound produced is three-carbon compound 3-PGA

Global warning - slow but steady rise in the Earth's temperature

Video :

Photosynthesis

Summarize :

This chapter explained the process of photosynthesis. The way plants can transform inorganic molecules into organic molecules. It described the way the light is accepted by chlorophyll and how the process continues inside Photosystems I and II and how it finishes up in Calvin cycle

Chapter 6

Questions :

What are the three main stages of cellular respiration ?

First stage is Glycolysis (breaking of glucose into pyruvate); the second stage is the Citric acid cycle (completes the the breakdown of glucose by decomposing a derivative of pyruvate to carbon dioxide); the third stage is Oxidative phosphorylation (here is generated H+ concentration and and thanks to electron transport chain the H+ molecules are transported back during chemiosmosis to generate A

TP).

What can interrupt cellular respiration ?

Certain poisons can block the cellular respiration. For example Cyanide and carbon monoxide, they bind with an electron carrier in forth protein complex. Cause of that electron cease to flow through and this stops the cellular respiration.

Another poison is oligomycin which blocks the passage of H+ through the channel in ATP synthase.

What is the outcome of ATP's for each phase ?

Glycolysis produces outcome of 2 ATPs and 2 NADH. Citric acid cycle produces 2 ATP, 6 NADH and 2 FADH2 . The oxidative phosphorylation produces the biggest number of ATP about 34 ATP molecules.

Diagram :

This diagram shows the citric acid cycle during which we breath out CO2. It's very complex cycle of reactions that repeats twice per molecule of glucose.

5facts :

Oxidative phosphorylation creates the biggest outcome of ATP (around 34).

Photosynthesis and cellular respiration provide energy for life.

C6H12O6 +6O2 -> 6CO2 + 6H2O + ATP energy - this is equation of cellular respiration.

Certain poisons are able to stop the process of cellular respiration .

Fermentation enables cells to produce ATP without oxygen.

Key terms:

Redox reaction - movement of electrons from one molecule to another

Oxidation - loss of electrons from one substance

Reduction - gain of electrons from one substance

Obligate anaerobes - prokaryotes that are poisoned by oxygen, they require only anaerobic conditions

Facultative anaerobes - can make ATP by either fermentation or oxidative phosphorylation

Lactic acid fermentation - process that enables the cell to create ATP without oxygen, some types of bacteria can regenerate NAD+

Intermediates - compounds that form between the initial reactant and the final product

Glycolysis - begins cellular respiration by breaking glucose into pyruvate

Kilocalories - the quantity of heat required to raise the temperature of 1 kilogram of water by 1C

Video :

Citric acid cycle

Summarize:

Chapter 6 described the cellular respiration. Basically the process that is going on inside our body everyday. It described the Citric acid cycle which is very important because it's the cell breathing. During this process we breath in O2 and breath out CO2. Also this chapter explained other phases of cellular respiration as well, such as glycolysis and oxidative phosphorylation during which our cells create most of ATP molecules.