Help with a spider?

Question

Spider-

Symmetry:

a) asymmetrical

b) radial

c) bilateral

Circulatory system:

a) none

b) open

c) closed

Reproduction:

a) asexual

b) sexual-- hermaphrodite

c) sexual-- seperate sexes

Digestion:

a) simple

b) complex

Nervous system:

a) none

b) rudimentary

c) developed

Locomotion:

i looked on wikipedia, and in my book and i can´t find it anywhere

Answer 1

The Spider has:

1)  Symmetry:

c)  bilateral symmetry : Symmetrical arrangement, as of an organism or a body part, along a central axis, so that the body is divided into equivalent right and left halves by only one plane.

2) Circulatory system:

b) open : Rear side of a spiderSpiders have an open circulatory system; i.e., they do not have true blood, or veins to convey it. Rather, their bodies are filled with haemolymph, which is pumped through arteries by a heart into spaces called sinuses surrounding their internal organs.

3) Reproduction:

c) sexual-- seperate sexes: Spiders reproduce by means of eggs, which are packed into silk bundles called egg sacs. Spiders often use elaborate mating rituals (especially the visually advanced jumping spiders) to allow conspecifics to identify each other and to allow the male to approach and inseminate the female without triggering a predatory response. If the approach signals are exchanged correctly, the male spider must (in most cases) make a timely departure after mating to escape before the female's normal predatory instincts return.

Sperm transmission from male to female occurs indirectly. When a male is ready to mate, he spins a web pad upon which he discharges his seminal fluid. He then dips his pedipalps (also known as palpi), the small, leg-like appendages on the front of his cephalothorax, into the seminal fluid, picking it up by capillary attraction. Mature male spiders have swollen bulbs on the end of their palps for this purpose, and this is a useful way to identify the s*x of a spider in the field. With his palps thus charged he goes off in search of a female. Copulation occurs when the male inserts one or both palps into the female's genital opening, known as the epigyne. He transfers his seminal fluid into the female by expanding the sinuses in his palp. Once the sperm is inside her, she stores it in a chamber and only uses it during the egg-laying process, when the eggs comes into contact with the male sperm for the first time and are fertilized; this may be why the vivipary has never evolved in spiders.[citation needed]

4) Digestion:

b) complex : The digestive system consists of a branched tube that extends from the mouth to the a**s. In the cephalothorax, the tube enlarges to form a stomach with powerful muscles. When these muscles contract, they produce a powerful sucking action that pulls food into the midgut.

Spider digestion is unusual in that it begins outside of the spider’s body. When a spider captures an insect or other animal, it uses its chelicerae to pierce the prey and inject poison into the wound to paralyze or kill the animal. The spider then vomits juices containing digestive enzymes into the wound of the victim to break down and liquefy its body tissue. This liquefied tissue is then drawn through the spider’s mouth and into its body by the sucking action of the stomach. Two mechanical filters in the mouth prevent solid food particles from passing into the digestive system.

From the stomach, food passes into the midgut, which branches throughout the entire body. Enzymes secreted by the midgut further break down the liquefied food into nutrient molecules small enough to pass through the walls of the midgut into the blood. Nutrients can be stored for a long time in the spider’s extensive digestive system, enabling many spiders to go for weeks or even months without the need to catch any prey.

5) Nervous system:

c) developed : Most arthropods have a central nervous system made up of a long chain of nerve cell centers called ganglia that run throughout the body. In spiders the ganglia are concentrated in the cephalothorax, where they condense into two compact masses: the sub-esophageal ganglion and the supra-esophageal ganglion. The sub-esophageal ganglion directs spider locomotion. The supra-esophageal ganglion is considered the brain of the spider. Sense organs throughout the body send information to this nerve center, where information processes and complex functions begin. A spider’s brain is relatively highly developed, enabling spiders to easily adapt to changes in their environment. Some scientists believe spiders can learn, and some have observed that spiders can remember where in their web they have stored captured prey; if the prey is removed, the spiders will continue searching for it in the same place for hours.

6) Locomotion:

Spiders have what is called an open circulatory system. The heart pumps blood through a series of vessels and arteries, but spiders lack the complex system of capillaries that in vertebrates exchange oxygen, nutrients, and wastes between the blood and body tissues. Instead, blood seeps between the spider's tissues, collects in little pockets on the underside of the body, and flows back to the heart. Not all blood passes through the spiders respiratory organs. An efficient, high-pressure ciculatory system is crucila for a spider's locomotion. Spiders have seven leg segments, and their movements are controlled by muscles and by pressure changes in the body's cirulatory fluid. Spiders use muscles to retract their legs, but they lack extensor muscles. Instead, spiders extend their legs by means of changes in body-fluid pressure. When spiders do not receive enough water to replenish their body fluids, their legs fold up and they are unable to extend them.

thank you for asking this question as I know all about spiders now :-)

Answer 2

Okay. The spider's symmetry is C: Bilateral

The spider's circulatory system is B: Open

The spider's reproduction is C: Seperate Sexes

The spider's digestion is fairly complex, so I would say B: complex.

The nervous system is, I believe C: Developed.

I'm sure about the first two questions. I am fairly sure about the next three questions

Answer 3

Symmetry: c) bilateral

Circulatory system: b) open

Reproduction: c) sexual-- seperate sexes

Digestion: b) complex

Nervous system: c) developed