Answer:
Explanation:
A convex lens acts a lot like a concave mirror. Both converge parallel rays to a focal point, have positive focal lengths, and form images with similar characteristics. A concave lens acts a lot like a convex mirror.
Answer:
Soma
Explanation:
Soma is the site at which the error of integrating an excitatory signal with other incoming signals occurred. Another name for Soma is perikaryon.
This signal integrates chemical encoding of signal transduction from all other incoming signals and this signal is not integrated properly with other incoming signals to that neuron.
Growth and repair
creation of gametes (sex cells)
method of reproduction in unicellular organisms
Binary Fission - type of reproduction that occurs in bacterial cells, single celled organism splits and becomes two identical organisms
Chromosomes and DNA
Chromosomes are DNA wrapped around proteins to form an X-shaped structure.
The diagram will help you see the relationship.
1. Chromosomes are found in the nucleus
2. Chromosomes are made of DNA
3. Sections of chromosomes are called genes
DNA - deoxyribonucleic acid (it is the genetic code that contains all the information needed to build and maintain an organism)
Chromosome Structure
Chromosome Numbers
Each organism has a distinct number of chromosomes, in humans, every cell contains 46 chromosomes. Other organisms have different numbers, for instance, a dog has 78 chromosomes per cell.
Somatic Cells - body cells, such as muscle, skin, blood ...etc. These cells contain a complete set of chromosomes (46 in humans) and are called DIPLOID.
Sex Cells - also known as gametes. These cells contain half the number of chromosomes as body cells and are called HAPLOID
Chromosomes come in pairs, called Homologous Pairs (or homologs). Imagine homologs as a matching set, but they are not exacly alike, like a pair of shoes.
Diploid cells have 23 homologous pairs = total of 46
Haploid cells have 23 chromosomes (that are not paired) = total of 23
Homologous Chromosomes
Sex Determination
Chromosomes determine the sex of an offspring. In humans, a pair of chromosomes called SEX CHROMOSOMES determine the sex.
If you have XX sex chromosomes - you are female
If you have XY sex chromosomes - you are male
During fertilization, sperm cells will either contain an X or a Y chromosome (in addition to 22 other chromosomes - total of 23). If a sperm containing an X chromosome fertilizes an egg, the offspring will be female. If a sperm cell containing a Y chromosome fertilizes an egg, the offspring will be male.
Creation of a Zygote
When two sex cells, or gametes come together, the resulting fertilized egg is called a ZYGOTE
Zygotes are diploid and have the total 46 chromosomes (in humans)
Karyotype
A karyotype is a picture of a person's (or fetus) chromosomes. A karyotype is often done to determine if the offspring has the correct number of chromosomes. An incorrect number of chromosomes indicates that the child will have a condition, like Down Syndrome
Compare the Karyotypes below
Notice that a person with Down Syndrome has an extra chromosome #21. Instead of a pair, this person has 3 chromosomes - a condition called TRISOMY (tri = three)
Trisomy results when chromosomes fail to separate - NONDISJUNCTION - when sex cells are created. The resulting egg or sperm has 24 instead of the normal 23.
Other conditions result from having the wrong number of chromosomes:
Klinefelters Syndrome - XXY (sex chromosomes)
Edward Syndrome - Trisomy of chromosome #13
Answer:
The correct answer is "the S layer may play a role in protecting cells from viruses and predatory bacteria found in nature but not in laboratory cultures".
Explanation:
The S-layer (surface layer) is a part of the cell's envelope comprised of of identical proteins or glycoproteins that could be found in archaes and some bacterias in nature. The function of the S-layer is unknown, however the fact that is only seen in nature suggest that it may play a role in protecting cells from viruses and predatory bacteria found in nature but not in laboratory cultures. It is likely that archaes and bacteria synthesize the S-layer when they recognize viruses and predatory bacteria in nature, the S-layer is not synthesized in laboratory cultures because these pathogens are not present.
The kind of knowledge that Rhonda used in the situation above is TACIT KNOWLEDGE. Tacit knowledge is not learned, it an inborn type of knowledge that helps one to understand and relate with other people as needed. Tacit knowledge usually have its foundation in one's belief, culture, value, mental models, skills, etc.
