Invertebrates/Description of Crayfish/Clam/Starfish/Squid

Complete a virtual dissection of a crayfish, clam, starfish and squid.

1. Detailed drawing of the organism and its organs/systems/parts with labels.
   2. Written description of the following system including level of complexity, organs, and function.
   a. digestive system
   b. circulatory system (indicate if it has one)
   c. nervous system
   d. excretory system
   e. reproductive system
   f. integumentary system (structure ie skin, exoskeleton, shell, etc.)
   g. body plan
   3. Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.

-Cray Fish-

Crayfish are found in streams, rivers, lakes and ponds where the water contains adequate amounts of calcium salts. They are primarily nocturnal, hiding in crevices and under rocks during the day and emerging to feed at night. They will eat almost anything organic - plant or animal, living or dead. Crayfish are arthropod because, it has invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin.

-Clam-

Hard clams inhabit the subtidal regions of bays and estuaries to approximately 15 meters in depth. They are generally found in mud flats and firm bottom areas consisting of sand or shell fragments. They can tolerate a wide range of salinities and live in brackish to saltwater conditions. Hard clams are extremely efficient filter feeders, and large hard clams can filter about a gallon of water per hour. As a result, they benefit water quality in coastal estuaries. Hard clams are also an important fisheries species.

-Starfish-

Starfish or sea stars are found in most of temperate and tropical oceans of the world. They are exclusively common and are bottom dwellers. Sea stars are found in a variety of habitats from the intertidal zone down to the bottom of deep seas but they are mainly found in shallow marine environments. They are found in sand, amongst rubble and on coral reefs and rocky bottoms below low tide as well as in estuaries and under the sand on beaches.

-Squid-

The squid is a member of the cephalopod family and is related to the octopus. Squid and other members of the cephalod family are actually mollusks that unlike clams or scallops lost most of their hard shells, although the squid does have the remnant of its shell which is called a cuttlebone. Squid are arrow shaped and have eight tentacles. They have the ability when excited to change their color, though they generally have a whitish hue.

Nudibranch

The fascinating Nudibranchs!!!.........???..

Fist of all, nudibranchs, also known as sea slugs, are soft-bodied marine snails belonging to the suborder Nudibranchia, the largest suborder of the order Opisthobranchia. There are more than 3,000 described species.

Do you know what nudibranch <- name means? Well, it comes from Latin "nudus" meaning nude, and from the Greek "brankia" meaning gills. So basically it means "naked gill."

Nudibranchs have cephalic (head) tentacles, which are sensitive to touch, taste, and smell. Also, they are hermaphrodictic, meaning that they can rarely fertilize themselves.

Here is the 180 degree turn, mostly everyone thinks that nudibranchs are herbivores. Well! they are wrong, because nudibranchs usually feast on sponges, hydroids, tunicates, anemones, corals, sea pens, bryozoans, barnacles, and sometimes other nudibranchs!

where in the ocean does it live: They are found in all over the world, also including British Isles, the tropics, and even the Antartics.
Description of life cycle (egg to death)

After mating, nudibranchs lay their egg masses either on or near the organism on which they feed. These egg masses vary in shape, size and colour depending on species. Some sea slugs lay single coils of eggs, while others are in the shape of a thick ribbon wound into a spiral. The egg masses are often white, but they can also be red, pink, orange or any other colour depending on the species. Egg development can take between 5 and 50 days, and is strongly influenced by temperature. Warmer waters generally result in a shorter embryonic period.
Usually the eggs develop first into a larval form called a veliger, which drifts in the ocean currents as plankton. Specific environmental conditions trigger the larvae to settle and metamorphose into the adult form. This larval dispersal is important in the successful exploitation of new areas, since adult nudibranchs move very slowly and cannot travel long distances.

How does it move (if it moves) The nudibranch moves by some mantle like structure.
Unique characteristics: It can feed on corals.
Role in the ecosystem: Anonymous!!!!!!!!!!!!!!!!!!!!!!!!!!

Kingdom-Animilia

Phylum- Mollusca

Class-Gastropoda

Sub Class-Opisthobranchia

Order- Nudibranchia

Family- Chromodorididae

Genus-Chromodoris

Species- Magnifica

DNA and RNA questions?? Oct 2nd

1. What is DNA? Deoxyribonucleic acid/ the blue print of life

2. What are the 4 bases? Adenine/thymine/cytosine/guanine

3. What 2 pieces of information did the scientists need to solve the elusive structure of DNA? Phosphate backbone was on the outside with bases on the inside; another that the molecule was a double helix

4. What are the specific base pairs? A/T/G/C

5. How does the pairing rule affect the shape and structure of DNA? Adenine-thymine pair that form a two-hydrogen bond together or a cytosine-guanine pair that form a three-hydrogen bond

6. What does the DNA do during cell division? During the cell division the DNA is copied in other words “unzipped” and copied exactly

7. How many base pairs does E. coli have? How long does it take to replicate? How is the DNA packaged in the cell? E. coli has 4,639,221 base pairs. It takes 40 minutes to replicate. E. coli is package in the DNA as eukaryotic chromosomes are packaged into the nucleus.

8. How many base pairs does Human DNA have? How long does it take to replicate? How is the DNA packaged in the cell? Over than 3 billion pairs. 12~24 hours. In a nucleus.

AFTER YOU'VE ANSWERED THE QUESTIONS, TRY PLAYING THE GAME. THEN MOVE ONTO THE NEXT ACTIVITY.

1. What is RNA? How different is it from DNA?

Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers. RNA is different from DNA by RNA is single stranded, while DNA is double stranded. Also, RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA uses predominantly uracil instead of thymine present in DNA.

2. How are the RNA messages formed?

RNA messages are formed by the grouping together of 3 of the letters to create a triplet or codon.

3. How are the RNA messages interpreted?

Ribosomes read the messages and then attach the amino acids together to make up a protein.

1. Describe cell cycle. Ribosomes read the messages and then attach the amino acids together to make up a protein.
Gap 1 phase: cell growth beginsSynthesis phase: chromosomes duplicate and divide; cell growth continuesGap 2 phase: cell reaches proper sizeMitosis phase: cell division

2. What is nuclear division. Nuclear division is the division of the nucleus and genetic information into more than one cell from a parent cell, usually through mitosis or meiosis.

3. What is interphase. When the cell or nucleus is not in mitosis.

4. Cytokinesis. The stage in meiosis in which the cytoplasm of the cell is divided after the nuclear division.

5. Homologous chromosomes. Pair of chromosomes that have the same genetic sequencing because they come from the same parent cell.

6. Phases of mitosis (5 of them). Prophase/Metaphase/Anaphase/Telophase/Interphase

7. Phases of meiosis and how it is different from mitosis. Early prophase/Late prophase/Metaphase/Anaphase/Telophase/Second Telophase/ *meiosis is different from mitosis because the cell goes through 2 divisions instead of just one and results in 4 daughter cells instead of only 2.

8. Describe the process and purpose of crossing over.Crossing over occurs when the sperm and egg chromosomes pair up and swap genetic information, reducing the number of chromosomes to a complete set.