photosynthesis and cellular respiration practice quiz

New Students

Welcome new students! I hope everyone had a great summer.
Supplies you will need for this class:
1) Composition notebook or a one subject notebook
2) Three ring binder and tabs for notes, quizzes and handouts
3) Blue or black pen and pencils.

Biology 1 Final!!

Refer to above schedule for your exam schedule!

Leave Questions here if you have any!!

Good Luck!

NOTES FOR CH. 13

13.1 RNA

Lesson Objectives

Contrast RNA and DNA.

Explain the process of transcription.

Lesson Summary

The Role of RNA RNA (ribonucleic acid) is a nucleic acid like DNA. It consists of a long chain of nucleotides. The RNA base sequence directs the production of proteins. Ultimately, cell proteins result in phenotypic traits. The main differences between RNA and DNA are:

The sugar in RNA is ribose instead of deoxyribose.

RNA is generally single-stranded and not double-stranded like DNA.

RNA contains uracil in place of thymine.

RNA can be thought of as a disposable copy of a segment of DNA. Most RNA molecules are involved in protein synthesis. The three main types of RNA are:

Messenger RNA (mRNA) carries copies of instructions for polypeptide synthesis from the nucleus to ribosomes in the cytoplasm.

Ribosomal RNA (rRNA) forms an important part of both subunits of the ribosomes, the cell structures where proteins are assembled.

Transfer RNA (tRNA) carries amino acids to the ribosome and matches them to the coded mRNA message.

RNA Synthesis Most of the work of making RNA takes place during transcription. In transcription, segments of DNA serve as templates to produce complementary RNA molecules. In prokaryotes, RNA synthesis and protein synthesis takes place in the cytoplasm. In eukaryotes, RNA is produced in the cell’s nucleus and then moves to the cytoplasm to play a role in the production of protein. The following focuses on transcription in eukaryotic cells.

The enzyme RNA polymerase binds to DNA during transcription and separates the DNA strands. It then uses one strand of DNA as a template from which to assemble nucleotides into a complementary strand of RNA.

RNA polymerase binds only to promoters, regions of DNA that have specific base sequences. Promoters are signals to the DNA molecule that show RNA polymerase exactly where to begin making RNA. Similar signals cause transcription to stop when a new RNA molecule is completed.

RNA may be “edited” before it is used. Portions that are cut out and discarded are called introns. The remaining pieces, known as exons, are then spliced back together to form the final mRNA.

13.2 Ribosomes and Protein Synthesis

Lesson Objectives

Identify the genetic code and explain how it is read.

Summarize the process of translation.

Lesson Summary

The Genetic Code A specific sequence of bases in DNA carries the directions for forming a polypeptide, a chain of amino acids. The types and order of amino acids in a polypeptide determine the properties of the protein. The sequence of bases in mRNA is the genetic code. The four bases, A, C, G, and U, act as “letters.”

The code is read three “letters” at a time, so that each “word” is three bases long and corresponds to a single amino acid. Each three-letter “word” in mRNA is known as a codon.

Some codons serve as “start” and “stop” signals for protein synthesis.

Translation Ribosomes use the sequence of codons in mRNA to assemble amino acids into polypeptide chains. The process of decoding of an mRNA message into a protein is translation.

Messenger RNA is transcribed in the nucleus and then enters the cytoplasm.

On the ribosome, translation begins at the start codon. Each codon attracts an anticodon, the complementary sequence of bases on tRNA.

Each tRNA carries one kind of amino acid. The match between the codon and anticodon ensures that the correct amino acid is added to the growing chain.

The amino acids bond together, each in turn. The ribosome moves along the mRNA, exposing codons that attract still more tRNAs with their attached amino acids.

The process concludes when a “stop code” is reached. The newly formed polypeptide and the mRNA molecule are released from the ribosome.

DNA REPLICATION STUDY GUIDE

        









                                      






                                    **Remember**
- DNA strands are anti-parallel (if one strand goes 3'-5' then the other strand goes 5'-3')
- DNA can only replicate 5'--3'
- Leading strand goes from the origin to the Fork
- Lagging strand goes from the fork to the origin
- Adenine always bonds with Thymine (A-T)
- Cytosine always bonds with Guanine (C-G)

Answers for Study guide!

1.       Give an example of a Homozygous Dominant, Homozygous Recessive and Heterozygous genotype.

 Homozygous Dominant = TT

 Heterozygous = Tt

 Homozygous resessive = tt

2.       What is a phenotype?

 It is the physical characteristic. What does the trait look like?

TT = Tall ;Tt = Tall; tt = Short

3.       Why did Mendel use Pea plants?

Easy to grow, create lots of offspring, can make pure traits, can control cross fertilization

4.       What were the parent and offspring genotypes and phenotypes in Mendel’s P1 cross?

 TTxtt         Genotypes = All Tt         Phenotype = All Tall

                  G. Ratio = All Alike           P Ratio = All alike

5.       What were the parent and offspring genotypes and phenotypes in Mendel’s F1 cross?

              TtxTt                     Genotypes = TT, Tt, tt                   Phenotypes = Tall; short

                                            G. Ratio = 1:2:1                            P. Ratio = 3:1

6.       What is the Law of Dominance?

 In a cross of pure contrasting traits all offspring will have heterozygous genotyoe and all take the dominant trait!

7.       What is the Law of Segregation?

          Alleles seperate in the formation of Gametes (sex cells) (sperm and egg) and then recombine during fertilization.

8.       What is the law of Independent assortment? And what kind of cross will show this?

 Alleles for different traits will seperate independently from one another. tall doesn't follow wrinkled seeds and short doesnt follow round seeds and so forth. You can see this in a Dihybrid cross

9.       How does Meiosis increase Genetic variability? And name where it happens.

1) Crossing over = Prophase 1
2)Independent assortment = Metaphase 1
3) Random fertilization = when the sperm fertilizes the egg
 

10) answers for pictures

1. Anaphase 1
2. Anaphase 2
3. Prophase 1
4. Metaphase 1
5. Metaphase 2
6. Telophase 1
7. Prophase 2
8. Telophase 2/ cytokinesis  This is the end product!

*** LEAVE ANY OTHER QUESTIONS UNDER THIS POST!!***

EXAM SCHEDULE

EXAM SCHEDULE:

WED JAN. 19: 
MOD A 8:00-9:30 - MOD B 10:00-11:30 - MAKE-UP 1:OO

THU. JAN. 20:
MOD C 8:00-9:30 - MOD D 10:00-11:30 - MAKE-UP 1:00

MON. JAN 24: 
MOD E 8:00-9:30 - MOD F 10:00-11:30 - MAKE-UP 1:00

TUE JAN. 25: 
MOD G 8:00-9:30 - MOD H 10:00-11:30 - MAKE-UP 1:00

** Leave a comment here if you have any questions about your review sheet!!**