Asexual Reproduction

Asexual reproduction involves _1_ parent. As a result, the offspring tend to have the same genotype (genes) and phenotype (look); they lack _diversity_. No _sex_ cells/gametes are involved.

Benefits: In a _stable_ environment a large number of offspring can be produced in a short time. Its _efficient_, takes less energy and all the offspring are viable (can reproduce)!

Drawbacks: If the environment is _unstable_ (think global warming or infectious diseases), offspring will have the same limited genes as their parent. The lack of gene variety mean that offspring are more vunerable to extinction!

 

Types of Asexual reproduction:

Binary Fission: offspring divide in half dividing the cytoplasm _equally_.

  • ex. Bacteria, ameoba, paramecium

Budding: offspring divide in half diving the _cytoplasm_ unequally

  • ex. Hydra, yeast

Vegetative Propagation: the reproduction of plants without _sex_

  • Bulb- an underground stem with fleshy leaves. ex. _garlic and tulips_
  • Tuber- a fleshy underground _stem_. ex. Sweet Potato
  • Stem Cutting- a _stem_ that can grow roots when planted. ex. Pothos
  • Runner- a _stem_ that grows roots. ex. Strawberries
  • Rhizome- an underground stem without leaves. ex. _ginger or iris__
  • _Grafting_- a root stock of one plant is connected to a shoot (scion) of another plant. ex. Apple trees

Sporulation: a single celled reproductive body with a _hard_ coating

  • ex. Bread mold

Regeneration: the regrowth of part of an animals body after its been _severed__

Parthenogenesis: development of an embryo from an unfertilized _sex_ cell

  • ex. Insects such as aphids and bees and some _reptiles_

Cloning: placing a nucleus of one cell into the egg cell of another (that's had its _nucleus__ removed)

  • Sheep, cats and __dog_ species

     

Vocabulary Words:

  • Binary Fission
  • Vegetative Propagation
  • Budding
  • Sporulation
  • Regeneration
  • Parthenogenesis
  • Cloning

Essential Questions:

  1. Know the different types of asexual reproduction.
  2. Be able to give examples of animals and plants that reproduce asexually
  3. Know the advantages and disadvantages of reproducing asexually

 

Parts of a Cell

 

How do animal cells differ from plant cells?

Animal Versus PLant Cells

  • Plant cells have cell _walls_, animal cells have cell membranes
  • Plant cells have chlorophyll/ chloroplast, animals don't
  • Plant cells have large _vacuole_
  • Animal cells have _centrioles_ and centrosomes, plants don't

Scale of the Small

Vocabulary Words:

  • Cell Membrane
  • Nucleus
  • Nucleolus
  • Nuclear pores
  • Nuclear membrane
  • Centrosome
  • Centrioles
  • Ribosomes
  • Rough Endoplasmic Reticulum
  • Mitochondria
  • Vacuole
  • Cell Wall
  • Cytoplasm
  • Chloroplast
  • Cell Wall

Essential Questions:

  1. Know the difference between animal and plant cells
  2. Be able to label the parts of an animal or plant cell given an illustration.
  3. Know which part of a cell is involved in reproduction.

 

 

DNA

  • DNA is a molecule that stores the hereditary material of organisms.
  • The information in DNA is used as a _genetic_ code to make an organism.
  • The DNA stands for deoxyribonucleic acid and is found in the _nucleus_ of a cell.
  • DNA is shaped like a double _helix_. Discovered by Watson and Crick.
  • The smallest unit of DNA is a nucleotide illustrated below. It has three parts: deoxyribose _sugar_, phosphates and one of the four possible nitrogen bases.
  • The nitrogen bases always join the _two_ DNA strands together in set pairs.
    • Adenine must pair with thymine, A=T or T=A
    • Guanine always pairs with cytosine, G=C or C=G
  • The two strands of DNA with its opposite nitrogen base pairs are called __complimentary_ DNA and are connected by a hydrogen bond.

 

DNA replication

  • When the cell is ready to duplicate, the DNA divides in ______ and creates an exact copy of itself!
    • DNA genetic code is unzipped by an enzyme that breaks the weak ___________ bond between the bases.
    • The split side acts as a template (pattern) for complimentary _______ bases.
  • Once the DNA duplication is complete, the cell divides in half forming _______ identical cells.

Mutations

  • Any change in the __________ of nucleotides in a DNA molecule can create a gene mutation.
  • If the mutation is in the sex cell it can be inherited, if it is in a __________ cell it can't.
  • Mutations may involve addition, ___________ or substitution of one nitrogen base for another.
  • Things that cause mutations include ____ light, radiation and toxic chemicals.

DNA Candy Lab!

 

DNA versus RNA

  1. DNA is the blueprint for who we are. RNA facilitates the process but doesn't ___________ it.
  2. DNA is double stranded/ RNA is ________
  3. DNA base pairs are adenine-thymine and guanine-cytosine. The RNA base pairs are adenine-_________ and guanine-cytosine. RNA replaces the thymine with uracil.
  4. DNA uses a deoxyribose sugar and RNA has a 5-carbon sugar called ________.

 

Steps to Creating New Proteins

  1. The ultimate goal of DNA is to instruct our cells to create ____________ (polypeptides).
  2. The DNA unzips when an enzyme breaks its weak __________ bonds.
  3. m-RNA called the messenger RNA reads (______________) the exposed DNA code by forming a complimentary strand of RNA from the nitrogen bases of the DNA. The DNA serves as the template of information to be read.
  4. The m-RNA travels from the nucleus to the ___________ in the cytoplasm (remember the rough endoplasmic reticulum?) to synthesize the proteins.
  5. T-RNA (transfer RNA) travels in groups of three base pairs with a specific amino acid. The tRNA ____________ the mRNA code on the ribosome by reading its complementary opposite code from the corresponding 3 adjacent nitrogen bases on the mRNA (codon). This causes the animo acids to be positioned close together so they can join together.
    • There are _____ different amino acids in cells.
  6. The amino acids join together and make a long stand called a ___________!

Proteins participate in every process of a cell. They form hormones, enzymes, new somatic (body) cells and much, much more!

 

Vocabulary Words:

  • DNA
  • Double Helix
  • Deoxyribose sugar
  • Phosphate
  • Nitrogenous base
  • Nucleotide
  • Adenine
  • Thymine
  • Guanine
  • Cytosine
  • Uracil
  • Chromatin
  • Chromosome
  • Complementary
  • Codon
  • Translation
  • Transcription
  • Protein
  • Hydrogen bonds
  • Polypeptide
  • mRNA (messenger)
  • tRNA (transfer)
  • Watson and Crick
  • Gene
  • Chromosome

 

Essential Questions:

  1. How does DNA differ from RNA
  2. What is the function of DNA?
  3. Describe the steps in replicating DNA and synthesizing protein.
  4. Where does protein synthesis occur?
  5. Where is the DNA located in the cell?
  6. What can happen during DNA replication that can cause mutations?
  7. What determines whether a mutation is inheritable or not?
  8. How many nitrogen bases are there and how are they paired?
  9. Be able to create a complementary m_RNA sequence from a DNA strand.
  10. What is the shape of DNA? Who discovered the shape?
  11.  What is a protein?
  12. What holds the nitrogen base pairs together in a DNA molecule?
  13. What makes up a nucleotide?
  14. Be able to label the parts of a codon.