blog #12

What surprised you from the worm's dissection?

It surprised me that the worm had so many internal organs. When I look at a worm from the outside of its body, it looks like it would just be all the same inside.  It just really surprised me how there was a brain, heart, intestines, etc.

 http://sekotin.co.cc/_cacheimg/w/o/worm%20dissecting.jpg

Blog #11

Alternation of generations (also known as alternation of phases or metagenesis) is a term primarily used in describing the life cycle of plants (taken here to mean the Archaeplastida). A multicellular diploid sporophyte, with N paired chromosomes (i.e. 2N in total), alternates with a multicellular haploid gametophyte, with N unpaired chromosomes. A mature sporophyte produces spores by meiosis, a process which results in a reduction of the number of chromosomes by a half. Spores germinate and grow into a gametophyte. At maturity, the gametophyte produces gametes by mitosis. Two gametes (originating from different organisms of the same species or from the same organism) fuse to produce a zygote, which develops into a diploid sporophyte. This cycle, from sporophyte to sporophyte (or equally from gametophyte to gametophyte), is the way in which all land plants and many algae undergo sexual reproduction.

All animals develop differently. A mature animal is diploid and so is, in one sense, equivalent to a sporophyte. However, an animal directly produces haploid gametes by meiosis. No haploid spores capable of dividing are produced, so neither is a haploid gametophyte. There is no alternation between diploid and haploid forms.

Other organisms, such as fungi, can have life cycles in which different kinds of organism alternate. The term 'alternation of generations' has also been applied to these cases.

Life cycles, such as those of plants, with alternating haploid and diploid phases can be referred to as diplohaplontic (the equivalent terms haplodiplontic, diplobiontic or dibiontic are also in use). Life cycles, such as those of animals, in which there is only a diploid phase are referred to as diplontic. (Life cycles in which there is only a haploid phase are referred to as haplontic.)

original text 

Bloh #10

Why is dissection an important part of a biology curriculum? Which animals and/or plants should be included in biological studies?

 I think that dissection is important for many reasons. It helps us better understand internal organs and how they work. There is no better way of understanding the insides of an animal and how they work than to actually open one up and observe the organs for yourself. hands on work is the best work.

http://www.newton.dep.anl.gov/askasci/gen06/gen06348.htm

 

 

1995 ^^^ 

2010vvv

blog #9

Define the different forms of community interaction: competition, commensalism, mutualism, predation, parasitism Give an example and a picture for each

competition: interaction in which organisms of the same or different species attempt to use the same
                   ecological resource in the same place at the same time.

 
mutalism: symbiotic relationship in which both species benefit from the relationship.

 

Predation: interaction in which one organism captures and feeds on another organism.

 

Parasitism: one organism, the parasite, benefits at the expense of the other, the host

Blog #4

Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words.

Directional Selection:

any genetic selection that shifts the population mean in the direction wanted by the breeder.

Stabilizing Selection:

the selection that the heterozygotes have the advantage

Disruptive Selection:

the slection that the natural selection favors the phenotypic extremes

  

Blog 8

Your choice talk about something you learned or ask a question about something that is confusing you

The only thing that I do not understand, is how 99% percent of the Earths animals that have ever existed are now extinct. I dont understand how this can happen.