Food Chains

A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals.

Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal.
Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water.
Animals cannot make their own food so they must eat plants and/or other animals. They are called consumers. There are three groups of consumers.
Animals that eat ONLY PLANTS are called herbivores (or primary consumers).
Animals that eat OTHER ANIMALS are called carnivores.
carnivores that eat herbivores are called secondary consumers
carnivores that eat other carnivores are called tertiary consumerse.g., killer whales in an ocean food web ... phytoplankton → small fishes → seals → killer whales
Animals and people who eat BOTH animals and plants are called omnivores.

FOOD CHAINS

On last class we was talking abaut food chains.

A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals. For example, a simple food chain links the trees & shrubs, the giraffes (that eat trees & shrubs), and the lions (that eat the giraffes). Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal.
1. Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water.
2. Animals can not make their own food so they must eat plants and/or other animals. They are called consumers. There are three groups of consumers.
a. Animals that eat only plants are called herbivores (or primary consumers).
b. Animals that eat other animals are called carnivores.
-carnivores that eat herbivores are called secondary consumers
-carnivores that eat other carnivores are called tertiary consumerse.g., killer whales in an ocean food web ... phytoplankton → small fishes → seals → killer whales.
3. Animals and people who eat BOTH animals and plants are called omnivores.
4. Then there are decomposers (bacteria and fungi) which feed on decaying matter. These decomposers speed up the decaying process that releases mineral salts back into the food chain for absorption by plants as nutrients.

In a food chain, energy is passed from one link to another. When a herbivore eats, only a fraction of the energy (that it gets from the plant food) becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore to carry out its life processes (movement, digestion, reproduction). Therefore, when the herbivore is eaten by a carnivore, it passes only a small amount of total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the carnivore, some energy will be "wasted" or "used up" by the carnivore. The carnivore then has to eat many herbivores to get enough energy to grow.Because of the large amount of energy that is lost at each link, the amount of energy that is transferred gets lesser and lesser ...

THE CALICO CAT!!

X-inactivation (also called lyonization) is a process by which one of the two copies of the X chromosome present in female mammals is inactivated. The inactive X chromosome is silenced by packaging into transcriptionally inactive heterochromatin. X-inactivation occurs so that the female, with two X chromosomes, does not have twice as many X chromosome gene products as the male, which only possess a single copy of the X chromosome (see dosage compensation). The choice of which X chromosome will be inactivated is random in placental mammals such as mice and humans, but once an X chromosome is inactivated it will remain inactive throughout the lifetime of the cell. Unlike the random X-inactivation in placental mammals, inactivation in marsupials applies exclusively to the paternally derived X chromosome. All mouse cells undergo an early, imprinted inactivation of the paternally-derived X chromosome in two-cell or four-cell stage embryos. The extraembryonic tissues (which give rise to the placenta and other tissues supporting the embryo) retain this early imprinted inactivation, and thus only the maternal X chromosome is active in these tissues. In the early blastocyst, this initial, imprinted X-inactivation is reversed in the cells of the inner cell mass (which give rise to the embryo), and in these cells both X chromosomes become active again. Each of these cells then independently and randomly inactivates one copy of the X chromosome. This inactivation event is irreversible during the lifetime of the cell, so all the descendants of a cell which inactivated a particular X chromosome will also inactivate that same chromosome. This leads to mosaicism if a female is heterozygous for an X-linked gene, which can be observed in the coloration of calico cats. X-inactivation is reversed in the female germline, so that all ova contain an active X chromosome. We hope you've got a nice time in Portugal kisses by Álvaro and Yesi

Calico cats are not a breed of cat; calico is a color pattern. To be called "calico", a cat must have black, white and orange in its coat. Variations of these colors include gray, cream and ginger. True calicos have large patches of these three colors, whereas a tortoiseshells or "torties" have a mix of these colors often blended or swirled together, rather than separate blocks of color. The size of the patches can vary from a fine speckled pattern to large areas of colour. Typically, the more white a cat has, the more solid the patches of color. In the UK, these cats are called "tortoiseshell and white".


Many people are surprised to learn that most cats with this coat pattern are female. This is due to genetics. Coat color in cats is a physical characteristic related to gender. Female animals have two X chromosomes (XX), males have one X chromosome and one Y chromosome (XY). The genetic coding for black or orange coat color is found on the X chromosome. The coding for white is a completely separate gene.



Since females have two X chromosomes, they can show two colors (orange and black, or variations of these) and white; creating the 3-color calico mix. Since males have only one X chromosome, they can only be orange OR black. The complex process of dominant and non-dominant genes comes into it too, but that is the basis for coat color in these cats. I did say that most calicos are female. They can be male in rare instances. In this case, the cat will have two X chromosomes and one Y chromosome (XXY). Cats with this chromosomal composition are usually sterile...is similar to a human condition called Klinefelter's syndrome.

http://es.youtube.com/watch?v=6A4fqf4YIkw&feature=related



This video shows the lessons that we were studying these weeks in class,
you can take to study or review the information so amazing about the human genetics that
here it explained that very well

sorry for the last error

http://es.youtube.com/watch?v=6A4fqf4YIkw&feature=related

HOMINIDS

Now we'll talk about hominids, one of the subjects that we studied in class.
The most important hominids are: the Homo Habilis, the Homo Erectus, the Homo Neanderthalensis and the Homo Sapiens (actual).

- THE HOMO HABILIS:

It lived approximately since 2'5 million years ago to 1'4 million years ago. Homo habilis is the first species of the homo genus to appear. It was the least similar to modern humans of all species of this genus. Homo habilis had a cranial capacity slightly less than half of the size of modern humans. Some fossils were found in Tanzania (Afric).

- HOMO ERECTUS:

It appeared 1'3 million years ago. its craneal capacity is larger than the Homo habilis one and the teeth are smaller These early hominines were tall, on average standing about 1.79 m and much stronger than modern humans. The brain size was expanding with time.
Some of the most important fossils were found in India, Tanzania, Indonesia, China and Kenia.

- HOMO NEANDERTHALENSIS:

It appeared in Europe about 500 thousand years ago and by 50,000 years ago, Neanderthalensis disappeared from Asia. Their cranial capacity was larger than modern humans, indicating that their brains may have been larger. This hominid may have live with Homo Sapiens up to 15,000 years after they had migrated into Europe.

Important fossils were found in China.

- HOMO SAPIENS:

It's the only one survival of the Homo genus. Compared to other species, humans have a highly developed brain, capable of abstract reasoning, language, introspection, and emotional suffering.

This mental capability, combined with an erect body that frees the arms for manipulating objects, has allowed humans to make a greater use of tools than any other species. Modern humans originated in Africa about 200,000 years ago. The human population on Earth now is estimated in 6.6 billion people.

Hominids

Now we'll talk about hominids, one of the subjects that we studied in class.

The most important hominids are: the Homo Habilis, the Homo Erectus, the Homo Neanderthalensis and the Homo Sapiens (actual).

- THE HOMO HABILIS:

It lived approximately since 2'5 million years ago to 1'4 million years ago. Homo habilis is the first species of the homo genus to appear. It was the least similar to modern humans of all species of this genus. Homo habilis had a cranial capacity slightly less than half of the size of modern humans. Some fossils were found in Tanzania (Afric).

- HOMO ERECTUS:

It appeared 1'3 million years ago. its craneal capacity is larger than the Homo habilis one and the teeth are smaller These early hominines were tall, on average standing about 1.79 m and much stronger than modern humans. The brain size was expanding with time.

Some important foss

ALBINOS

On the last class, on Friday, 16th of May, we studied the alleles, genotypes and the phenotypes. And with this theme we had an exercise of albinos and so we began to talk about these humans.
Our teacher showed us the news of the newspaper "El País" from the day, 6th of May of 2008. The news surprised us greatly; it spoke about the plight of albinos in Tanzania. Where, nothing else birth, they are rejected. Usually by their fathers, who abandoned their children’s and their mothers. For the fathers, the mothers are the guilty of the condition.
These children have got many difficulties at school to see to the blackboard. Teachers and classmates discriminate and insult these people. Finding a job is very difficult, they are marginalized. The albinos suffer problems optical and the African sun, harsh, causing sores and burn them. Many albinos die young, caused of a skin cancer.

In fishing areas in Tanzania, where poverty is combined with superstition, it isn’t treating as a marginalized, but as a murder. 20 people with albinism were killed and maimed in the last year.
The president of Tanzania, Jakaya Kikwete, is determined to end with the superstition and he said in a televised speech last month that he will finish with the ideas of the sorcerers. So far they have arrested more than a hundred people involved in the murders and it has been appointed the first parliamentary albino, Al Shaymaa Kwegyr, to combat against the discrimination that people suffered with this genetic condition.

The “TAS” is the Organization of Albinos in Tanzania, which count with the help of Action on Disability and Development, that is looking that the albinism is recognized as a disability.

Between the first tasks of Kwegyr is to conduct a census of people with albinism to ensure their access to education and health treatments.

Sometimes in occasions, mothers are accused of having sex with white men, in others, to have maintained relations with “tokoloshes”, evil spirits.

It’s estimated that there are more than 200,000 albinos in Tanzania. South Africa is one of the few countries, which recognizes the genetic condition as a disability

There are more albinos in Africa than anywhere else in the world. In fact, the first Portuguese colonizers designated these humans as a breed apart.

Jennifer and Silvia

GENETIC

Last class, we talked about genetic. That it’s what we learnt

Genetics, a discipline of biology, is the science of heredity and variation in living organisms.

Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides: adenine (A), cytosine (C), guanine (G), and thymine (T).

Genes are arranged linearly along long chains of DNA sequence, called chromosomes. In bacteria, each cell has a single circular chromosome, while eukaryotic organisms have their DNA arranged in multiple linear chromosomes.

While haploid organisms have only one copy of each chromosome, most animals and many plants are diploid, containing two of each chromosome and thus two copies of every gene.

In humans and other mammals the Y chromosome has very few genes and triggers the development of male sexual characteristics, while the X chromosome is similar to the other chromosomes and contains many genes unrelated to sex determination. Females have two copies of the X chromosome, but males have one Y and only one X chromosome—this difference in X chromosome copy numbers leads to the unusual inheritance patterns of sex linked disorders

A genotype describes the actual set (complement) of genes carried by an organism. In contrast, phenotype refers to the observable expression of characters and traits coded for by those genes.

Although phenotypes are based upon the content of the underlying genes comprising the genotype, the expression of those genes in observable traits (phenotypic expression) is also, to varying degrees, influenced by environmental factors.

A clear example of the relationship between genotype and phenotype exists in cases where there are dominant and recessive alleles for a particular trait. Using an simplified monogenetic (one gene, one trait) example, a capital "B" might be used to represent a dominant allele at a particular locus coding for tallness in a particular plant, and the lowercase "b" used to represent the recessive allele coding for shorter plants. Using this notation, a diploid plant will possess one of three genotypes: BB, Bb, or bb (the variation bB is identical to Bb). Although there are three different genotypes, because of the laws governing dominance, the plants will be either tall or short (two phenotypes). Those plants with a BB or Bb genotype are observed to be tall (phenotypically tall). Only those plants that carry the bb genotype will be observed to be short (phenotypically short).

Here the relation between genotype and phenotype is illustrated for the character of petal colour in pea. The letters B and b represent genes for colour and the pictures show the resultant flowers.

Same of Biology..

The biology refers to a Life Science, is the study of life.

With the biology we can examine the structure, function, growth of living bains.


Are different tipes of Biology studys:

Zoology, the study of animals; and microbiology, the study of microorganisms. The fields within biology are further divided based on the scale at which organisms are studied and the methods used to study them: biochemistry examines the fundamental chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellullar biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues and organ systems of an organism; and ecology examines how various organisms and their environment interrelate.



Moderns biology and its theories:


Cell theory. All living organisms are made of at least one cell, the basic unit of function in all organisms. In addition, the core mechanisms and chemistry of all cells in all organisms are similar, and cells emerge only from preexisting cells that multiply through cell division.


Evolution. Through natural selection and genetic drift, a population's inherited traits change from generation to generation.


Gene theory. A living organism's traits are encoded in DNA, the fundamental component of genes. In addition, traits are passed on from one generation to the next by way of these genes.

All information flows from the genotype to the phenotype, the observable physical or biochemical characteristics of the organism.



Important Biologist:

Charles Darwin, is the creater of the theory of Natural Selection.
Alexander von Humboldt, investigated the interaction between organisms and their environment.
Thomas Hunt Morgan and his students, and by the 1930s the combination of population genetics.
Watson and Crick, proposed the structure of DNA...

Chema, álvaro y María

Group 1

Our classmates

Sabela & Reyes

have been selected to participate
in the Galician stage of the
Chemistry Mini-Olympics

¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡ CONGRATULATIONS !!!!!!!!!!!!!!!!!!